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MANUAL 
 
 oF 
 
 MINERALOGY AND LITHOLOGY: 
 
 ' CONTAINING THE 
 
 ELEMENTS OF THE SCIENCE OF MINERALS 
 AND ROCKS. 
 
 FOR THE USE OF 
 
 THE PRACTICAL MINERALOGIST AND GEOLOGIST, AND FOR 
 INSTRUCTION IN SCHOOLS AND COLLEGES. 
 
 By JAMES D. DANA. 
 
 Fourth Cvition, 
 
 RE-ARRANGED AND RE-WRITTEN. 
 
 —sMustrated bp Iumerous Wloodcuts, 
 
 LONDON: 
 
 TRUBNER & CO., LUDGATE HIML. 
 
 1882. 
 [All rights reserved. | 
 

 
 
 
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PREFACE. 
 
 Ty1s Manual in its present shape is new throughout. In the reno- 
 vation it has undergone, new illustrations have been introduced, an im- 
 proved arrangement of the species has been adopted, the table for the 
 - determination of minerals has been reconstructed, and the chapter on 
 rocks has been expanded to a length and fullness that renders it a 
 prominent part of the work. But while modified greatly in all its 
 parts, it is still simple in its methods of presenting the facts in crys- 
 tallography, and in all other explanations ; and special prominence is 
 given, as in former editions, to the more common minerals, with only 
 a brief mention of others. The old practical feature is retained of 
 placing the ores under the prominent metal they contain, and of giving 
 ‘in connection some information as to mines and mining industry. 
 
 The student is referred to the Text-book of Mineralogy, prepared 
 mainly by Mr. HE. 8. DANA, for a detailed exposition of the subject of 
 crystallography after Naumann’s and Miller’s systems, and also of 
 optical mineralogy and other physical branches of the science; to 
 the Manual of Determinative Mineralogy and Blowpipe Analysis by 
 Professor GrorcE J. Brusu, for a thorough work on the use of the 
 blowpipe, and complete tables for the determination of minerals ; 
 and to the author’s Descriptive Mineralogy and its Appendixes fora 
 comprehensive treatise on all known minerals. 
 
 | JAMES D. DANA. 
 New Haven, Nov. 1, 1878. 
 

 
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TABLE OF CONTENTS. 
 
 MINERALOGY. 
 
 Mrneraus: General Remarks ............... eee sree eee 1 
 
 I CRYSTALLIZATION OF MINERALS: CRYSTALLOGRAPHY. 
 
 1. General Remarks on Crystallization. ......---++-+++++++- 4 
 9, Descriptions of Crystals. ......0.---. sere ere tree rete 8 
 Explanation of Terms. .........---- sess seer eer eeces 8 
 Measurement of Angles ; Goniometers..........-.--- 9 
 
 J. Sysrems oF CRYSTALLIZATION : Forms and Struc- 
 
 ture of (rystals..........--.-. see cence ences: eel 
 
 1, Isometric System............-. eee eee eee FA. GR 17 
 
 9 Dimetric or Tetragonal System........-. eee ee eee reer 30 
 
 3. Trimetric or Orthorhombic System.......-. +--+ +++s sees ays 
 
 4, Monoclinic System.......----. 2+ eee tere tees nee Pees 40 
 
 5. Triclinic System.......-.--+sseeseeeer eres etree te 2 AO 
 
 6. Hexagonal System.......--20++-- cree erste rete er ents 45 
 
 1. Hexagonal Section.........---. sess eeeer eee AG 
 
 9 Rhombohedral Section. ......---.++e seer seers 49 
 
 7. Distinguishing Characters of the Systems.......-.----+! ». 54 
 
 Il. Twin oR CoMPOUND CRYSTALS.........-.0:0- +0200 e> 55 
 
 II]. CRYSTALLINE AGGREGATES. ........ 00. cere e rece eres 58 
 Il. PHYSICAL PROPERTIES OF MINERALS. 
 
 Et re ie sg hs dr sees eee ee 63 
 
 eG ier oad ss kes vee ene eT 64 
 
 Be Mele Gravity...5 wee ce Orne Cont gg Se ne 64 
 
 4. Refraction and Polarization ........+++-+sseerec strstr 66 
 
 5. Diaphaneity, Lustre, Color......-++++s+sestrrsrersr sree 70 
 
 6. Electricity and Magnetism. ......--.++++sserrrctere trent: 73 
 
 Pe acts Ot yen sno oes esr careers bee Tse eS 74 
 
inf. 
 
 TABLE OF CONTENTS. 
 Ill. CHEMICAL PROPERTIES OF MINERALS. 
 
 PAGE 
 
 1. Chentical Composition. . ig)... ..<2.+5 +055 sae eee 76 
 2. Chemical "Reactions. 2.4 i250. .<55. s+ cn « dee eee 81 
 1. Trials inthe Wet) Way........ +22 sien 81 
 
 2. Trials with the Blowpipe..............:4.)se 82 
 
 IV. DESCRIPTIONS OF MINERALS. 
 
 1. Classification .. . 0% 058s i<. 600.04 0h sacs gee ee 91 
 2. General Remarks on Ores, .:........+ «&olse 2s eee 92 
 
 I. MINERALS CONSISTING OF THE ACIDIC ELEMENTS. 
 
 1, Salphar Group 3... . i.s.c5 ofan cic » wie s2es eee 94 
 2. BOTONPOATOUD, oo 0s aise oe ses toe 5 +» kee See o7 
 8. Arsenic Group... | oo. 6 6.4 es sue 2 98 
 4, Carbon Group, ... 5 .-20:ss'¢0+cei00 46 5 ie «aie geet an 102 
 
 MINERALS CONSISTING OF THE BASIC ELEMENTS WITH 
 OR WITHOUT ACIDIC—THE SILICATES EXCLUDED. 
 GOL. wise + ee bs 5 sate g's 06 Bellen mie clei miattelstn 5a oer 109 
 Silver and its Compounds, .\.5.5..5.<52--< sree eae 116 
 Platinum, Iridium, Rutheninm..4 7... ee 124 
 Palladium... 0.22000 tae «ie ce ew 5 reine ores 127 
 Mercury and its Compounds... ...... . .\e:gesee eee 128 
 Copper and its Compounds. ............ sees nee 1380 
 Lead and its Compounds.......5 .s- sss 00h ee oe eee 145 
 Zine and its Compounds......:.........0. 29 a"e 154 
 Cadmium, Tin: 2. cee 6s 6d one wince Gon wee ogee te eer 159 
 Compounds of ‘Titanium.,........5.,....-5= 5 thee oe ee 162 
 Cobalt and Nickel and their Compounds.................... 163 
 Uranium and its Compounds... ........- 9 seeee ee 169 
 Tron and its Compounds... .....22...4.-5- see eee 171 
 Manganese and its Compounds,........,..s004s see seen 188 
 Compounds of Aluminum. 5. 15% sa~ «==. ee 192 
 
 Compounds of Cerium, Yttrium, Expinne Lanthanum and 
 Didymitim 5200.22 202% eed os fen eee PE i 201 
 Compounds of Magnesium... :..:...:. .2se5 esewa eee 204 
 Compounds of Calcium.:-.). 6.05. 6.60.0. «<s0g ae Oana 207 
 Compounds of Barium and Strontium....................-. 220 
 Compounds of Potassium and Sodium....................-. 223 
 Compounds of Ammonium... 2.252205 sss « set eens 230 
 
 Compounds of Hydrogen........ WOOTETE EE 231 
 
TABLE OF CONTENTS. vii 
 IIf. SrnicA AND SILICATES. 
 1. SILICA. PAGE 
 SE: Sete PE SIRS cea a a dt Sa a 233 
 Ie OM aes oa 5c eins © Ne wlns oui oles odeeitee esas + 239 
 9, SILICATES 
 Cierra Rear... ces hace etter eset ewer see eee serer ences 242 
 1. Anhydrous Silicates 
 
 PRGA LOR oes ene va ren ene ens een en wean es enee se cits 243 
 Pyroxene and Amphibole Groupriiee esi vost vee se 244 
 CHa rcs feces teers ot tnt rte ears sce: R02 
 
 Ste TGAUCa co. wy occr she erin sree rsh eos apemes fee 204 
 Chrysolite Group. ....--se ee eee cere sete e ence cece ees 259 
 ERR LOUD cy vas os er ene de we er ase ese s 256 
 Pircon Group... ...- 20. e cece ede ce eters secre ccsecies 209 
 Idocrase, Epidote, etc. ...... eee ee reese eee e reer ees 261 
 Axinite, Iolite.........: 5 ORES Pierre ee ee 264 
 Mipa GTO: gies ers n ee ee eee sree eters aisae ee 265 
 Beapolite Groupseem. ---- 0... esos cent ers sewn enlnee 268 
 Nephelite, Sodalite, Leucite......-.+++eeeeererreeeee 269 
 Waldspar toupee oe. wes tee. oe ek nite wet ia oe 7 
 
 B, Subsilicates........-.-.--e sees cree reeset ee certs pa Ae 280 
 
 Chondrodite, Tourmaline..........-+seeeee reer tees 281 
 Andalusite, Fibrolite, Cyanite........+-.-+e+srereees 284 
 Topan, Puclate. . 2. ves. wee sss ne verre eee cee et ee 288 
 Datolite, Sphene, Staurolite.........-seeeeee eer ereees 289 
 
 2. Hydrous Silicates. 
 
 Perr) BOCHON: cc 6). oe. sees ce ees ee eee rete ree 292 
 Pectolite, Laumontite, Apophyllite cuth vat Ge «pete chien 293 
 Prehnite, Allophane. ......-..-sssereveererterrcetes 299 
 
 ee HO asmeet Ol s oat fa cc ashe Abinto <M steice eset Qt wet 297 
 Thomsonite, Natrolite, Analcite, Chabazite......+..-- 298 
 Harmotome, Stilbite, Heulandite.........--++ses-re> 301 
 
 8. Margarophyllite Section. ......---esseseeeere seers ttt 304 
 Talc, Pyrophyllite, Sepiolite......-+:.-seeeereeereees 304 
 Serpentine, Deweylite, Saponite......-ce.eeerssseeres 307 
 re ANG se PDTC, nies Mosel + sobs ei cers or NN = Hong? 310 
 Hydromica Group... ...-+.sseeecereeeeetere ss ‘en Whee 312 
 Fahlunite, Hisingerite...........eceecere cere centres old 
 CMe he ALOU Dy diets vies ee eens vier atte ee eens 516 
 
Vill TABLE OF CONTENTS. 
 
 IV. HyprocarBon CompounpDs. 
 
 PAGE 
 1.. Simple Hydrocarbons:.. (seers. we. = oa aoe ee 821 
 2. Oxygenated Hydrocarbons. |... 5... + -psiu cee eee 320 
 3. Asphaltum and Mineral Coals... ... #0 Gee. ieee eet 326 
 
 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 1. Catalogue of American Localities of Minerals............. 3080 
 2. Brief Notice of Foreign Mining Regions.................. 375 
 IV. DETERMINATION OF MINERALS. 
 
 + General Remarks. ......5.%.0.0s0s5 aces ss see 9h ener 379 
 Table for the Determination of Minerals............+.++-2++-+6: 384 
 ON ROCKS. 
 
 2. Constituents of Rocks. <.1.:wiec.-e es = Mmmm di oe oye ane ne 409 
 2. Classes of Rocks... 24. 5..5 500 ss. en eee 412 
 8. On some Characteristics of Rocks............-.0-0.0eeceeeees 414 
 Use of the Microscope in the Study of Rocks.............. 422 
 4, Kinds of Rocks..........0¢...00 0050 0s 0 )0 = on 424 
 1, Fragmental Rocks, exclusive of Limestones............ 426 
 2. Limestones or Calcareous Rocks..............-.--.+26- 430 
 8. Crystalline Rocks, exclusive of Limestones............ 434 
 1. Siliceous Rocks.....<... .. ss se 52) oe) ee 485 
 2. Mica and Potash-Feldspar Series...............-. 437 
 38. Mica and Soda-lime Feldspar Series...........- 443 
 4. Hornblende and Potash-Feldspar Series.......... 444 
 5. Hornblende and Soda-lime Feldspar Series..... .. 446 
 6. Pyroxene and Soda-lime Feldspar Series......... 450 
 7. Pyroxene, Garnet, Epidote, and Chrysolite Rocks, 
 containing little or no Feldspar.............. 452 
 8. Hydrous Magnesian and Aluminous Rocks...... 458 
 9, Tron-ore Rocksi ss cssesseresy eee w een enee 455 
 
MINERALOGY. 
 
 MINERALS. 
 
 Minerats are the materials of which the earth consists, and 
 plants and animals the living beings over the surface of the 
 mineral-made globe. A few rocks, like limestone and quartz- 
 yte, consist of a single mineral in more or less pure state; but 
 the most of them are mixtures of two or more minerals. 
 Through rocks of each kind various other minerals are often 
 distributed, either in a scattered way, or in veins and cavities. 
 Gems are the minerals of jewelry; and ores, those that are im- 
 portant for the metal they contain. Water is a mineral, but 
 generally in an impure state from the presence of other miner- 
 als in solution. The atmosphere, and all gaseous materials set 
 free in volcanic and other regions, are mineral in nature, 
 although, because of their invisibility, seldom to be found 
 among the specimens of mineral cabinets. Even fossils are 
 mineral in composition. This is true of coal which has come 
 from buried plant-beds, and amber from the buried resin of 
 ancient trees, as well as of fossil shells and corals. 
 
 It is sometimes said that minerals belong to the mineral 
 kingdom, as plants to the vegetable kingdom, and animals to 
 the animal kingdom. Substituting the term inorganic for min- 
 eral, the statement is right ; for, as there are the two kingdoms 
 of life, so there is in Nature what may be called a kingdom, or 
 grand division, including all species not made through the 
 organizing principle of life. But this inorganic kingdom is not 
 restricted to minerals; it embraces all species made by inor- 
 ganic furces—those of the earth’s crust or surface, and, also, 
 whatever may form under the manipulations of the chemist. 
 The laws of composition and structure, exemplified in the consti- 
 tution of rocks, are those also of the laboratory, A species made 
 
 1 
 
2 CHARACTERS OF MINERALS. 
 
 by art, as we term it, is not a product of art, but a result solely 
 of the fundamental laws of composition which are at the basis 
 of all material existence; and the chemist only supplies the 
 favorable conditions for the action of those laws. Mineral 
 species, are then, but a very small part of those which make up 
 the inorganic kingdom or division of Nature. 
 
 CHARACTERS OF MINERALS. 
 
 1. Minerals, unlike most rocks, have a definite chemical 
 composition. This composition, as determined by chemical 
 analysis, serves to define and distinguish the species, and indi- 
 cates their profoundest relations. Owing to difference in com- 
 position, minerals exhibit great differences when heated, and 
 when subjected to various chemical reagents, and these peculi- 
 arities are a means of determining the kind of mineral under 
 examination in any case. The department of the science treat- 
 ing of the composition of minerals and their chemical reactions 
 is termed CHEMICAL MinEeratoey. 
 
 2. Each mineral, with few exceptions, has its definite form, 
 by which, when in good specimens, it may be known, and as 
 truly so as a dog or cat. These forms are cubes, prisms, double 
 pyramids, and the like. They are included under plane sur- 
 faces arranged in symmetrical order, according to mathematical 
 law. These forms, in the mineral kingdom, are called crystals. 
 Besides form there is also, as in living individuals, a distinctive 
 internal structure for each species. ‘he facts of this branch of 
 the science come under the head of CrystaLLocRaPHic MinER- 
 ALOGY. 
 
 3. Minerals differ in hardness—from the diamond at one end 
 of the scale to soapstone at the other. There is a still lower 
 limit in liquids and gases; but of the hardness or cohesion in this 
 part of the series the mineralogist has little occasion to take 
 note. 
 
 Minerals differ in specific gravity, and this character, like 
 hardness, is a most important means of distinguishing species. 
 
 Minerals differ in color, transparency, lustre, and other opti- 
 cal characters. 
 
 A few minerals have taste and odor, and when so these char- 
 acters are noticed in descriptions. 
 
 The facts and principles relating to the above characters 
 are embraced in the department of PHysicaL MINERALOGY. 
 
 In addition to the above-mentioned branches of the science 
 
CHARACTERS OF MINERALS. a 
 
 of minerals there is also (4) that of DescripriveE MINERALOGY, 
 under which are included descriptions of the mineral species 5 
 and (5) that of DerrrminativeE MinERALOGY, which gives a 
 systematic review of the methods for determining or distinguish- 
 ing minerals. 2 
 
 These different branches of the subject are here taken up in 
 the following order: I. Crystallographic Mineralogy; II. Phys- 
 ical Mineralogy; III. Chemical Mineralogy; IV. Descriptive 
 Mineralogy ; V. Determinative Mineralogy. On account of 
 the brief manner in which the subjects are treated in this 
 volume, the heads used for the several parts are, (1) Zhe Crys- 
 tallization of Minerals ; (2) Physical Properties of Minerals ; 
 (3) Chemical Properties of Minerals ; (4) Descriptions of Spe- 
 
 cies » (5) Determination of Minerals. 
 
4 CRYSTALLOGRAPILY, 
 
 1. CRYSTALLIZATION OF MINERALS: 
 CRYSTALLOGRAPHY. 
 
 1. GeneraL REMARKS ON CRYSTALLIZATION. 
 
 THE attraction which produces crystals is one of the funda- 
 mental properties of matter. It is identical with the cohesion 
 of ordinary solidification ; for there are few cases outside of the 
 kingdoms of life in which solidification takes place without some 
 degree of crystallization. Cohesive attraction is, in fact, the 
 organizing or structure-making principle in inorganic nature, it 
 producing specific forms for each species of matter, as life does 
 for each living species. A bar of cast-iron is rough and hackly 
 in surface, because of the angular crystalline grains which the 
 iron assumed as solidification took place. A fragment of mar- 
 ble glistens in the sun, owing to the reflection of light from in- © 
 numerable crystalline surfaces, every grain in the mass having 
 its crystalline structure. When the cold of winter settles over 
 the earth in the higher temperate and colder latitudes it is the 
 
 
 
 CRYSTALS OF SNuW., 
 
 signal for crystallization over all out-door nature; the air is 
 filled with crystal flakes when it snows; the streams become 
 coated with an aggregation of crystals called ice; and windows 
 are covered with frost because crystal has been added to crystal 
 
CRYSTALLOGRAPHY. 5 
 
 in long feathered lines over the glass—Jack Frost’s work being 
 the making of crystals. Water cannot solidify without crystal- 
 lizing, and neither can iron nor lead, nor any mineral material, 
 with perhaps half a dozen exceptions. Crystallization produces 
 masses made of crystalline grains when it cannot make distinct 
 crystals. Granite mountains are mountains of crystals, each 
 particle being crystalline in nature and structure. Toe lava 
 current, as it cools, becomes a mass of crystalline grains. In 
 fact the earth may be said to have crystal foundations; and if 
 there is not the beauty of external form, there is everywhere 
 the interior, profounder beauty of universal law—the same law 
 of symmetry which, when external circumstances permit, leads 
 to the perfect crystal with regular facets and angles. 
 
 Crystals are alone in making known the fact that this law 
 of symmetry is one of the laws of cohesive attraction, and that 
 under it this attraction not gnly brings the particles of matter 
 into forms of mathematical @rometry, but often develops scores 
 of brilliant facets over their surface with mathematical exact- 
 ness of angle, and the simplest of numerical relations in their 
 positions. Crystals teach also the more wonderful fact that 
 the same species of matter may receive, under the action of this 
 attraction, through some yet incomprehensible changes in its 
 condition, a great diversity of forms—from the solid of half a 
 dozen planes to one of scores. ‘The following figures represent a 
 few of the forms in a common species, pyrite, a compound of 
 iron and sulphur. 
 
 
 
6 CRYSTALLOGRAPHY. 
 
 Sore « 
 
 
 
 Many more figures might be given for this one species, py- 
 rite. The various forms or planes in any such case have, it is 
 true, mutually dependent relations—a fact often expressed by 
 saying that they have a common Jundamental form. But it is 
 none the less a remarkable fact, giving profound interest to the 
 subject, that the attraction, while having this degree of unity 
 in any species, still, under each, admits of the multitudinous 
 variations needed to produce so diverse results, 
 
 At the time of crystallization the material is usually in a 
 
ORYSTALLOGRAPHY. 1 
 
 state of fusion, or of gas or vapor, or of solution. In the case 
 of iron the crystallization takes place from a state of fusion, and 
 while the result is ordinarily only a mass of crystalline grains, 
 distinct crystals are sometimes formed in any cavities. If in 
 the cooling of a crucible of melted lead, bismuth, or sulphur, the 
 crust be broken soon after it forms, and the liquid part within be 
 turned out, crystals will be found covering the interior. Here, 
 also, is crystallization from a state of fusion. When frost or 
 snow-flakes form it exemplifies crystallization from a state of 
 _vapor. Ifa saturated solution of alum, made with hot water, 
 be left to cool, crystals of alum after awhile will appear, and 
 will become of large size if there is enough of the solution. A 
 solution of common salt, or of sugar, affords crystals in the 
 same way. Again, whenever a mineral is produced through 
 the change or decomposition of another, and at the same time 
 assumes the solid state, it takes at once a crystalline structure, 
 if it does not also develop crystals. 
 
 Further, the crystalline texture of a solid mass may often be 
 changed without fusion: ¢. 7., in tempering steel the bar is 
 changed from coarse-grained steel to fine-grained by heating 
 and then cooling it suddenly in cold water, and vice versa, and 
 this is a change in every grain throughout the bar. 
 
 Thus the various processes of solidification are processes of 
 crystallization, and the most universal of all facts about miner- 
 als is that they are crystalline in texture. A few exceptions 
 have been alluded to, and one example of these is the mineral 
 opal, in which even the microscope detects no evidence of a 
 crystalline condition, except sometimes in minute portions sup- 
 posed not to be opal. But if we exclude coals and resins this 
 mineral stands almost alone. Such facts, therefore, do not 
 affect the conclusion that a knowledge of crystallography is of 
 the highest importance to the mineralogist. It is important 
 because— 
 
 1. A study of the crystalline forms and structure of minerals 
 is a convenient means of distinguishing species—the crystals 
 of a species being essentially constant in structure and in 
 angles. 
 
 9. The most important optical characters depend on the 
 crystallization, and have to be learned from crystals. 
 
 3, The profoundest chemical relations of minerals are often 
 exhibited in the relations of their crystalline forms. 
 
 4, Crystallization opens to us nature at her foundation work 
 and illustrates its mathematical character. 
 
8 ORYSTALLOGRAPHY. 
 
 2. DESCRIPTIONS OF CRYSTALS. 
 
 In describing crystals there are two subjects for considera- 
 tion: First, Form; and secondly, Structurr. 
 
 A. Form.—Under form come up for description, not only 
 the general forms of crystals, but also— 
 
 (1.) The systems of crystallization, that is, the relations of 
 all crystalline forms, and their classification. 
 
 (2.) The mutual relations of the planes of a crystal as ascer- 
 tained through their positions and the angles between them. 
 
 (3.) The distortions of crystals. The perfection of symmetry 
 exhibited in the figures of crystals, in which all similar planes 
 are represented as having the same size and form, is seldom 
 found in nature, and the true form is often greatly disguised by 
 this means. ‘The facts on this point, and the methods of avoid- 
 ing wrong conclusions need to be understood, and these are 
 given beyond. With all such imperfections the angles of crys- 
 tals remain essentially constant. There are irregularities also 
 from other sources. 
 
 (4.) Twin or compound crystals. With some species twins 
 are more common than regular crystals, . 
 
 (5.) Crystalline aggregates, or combinations of imperfect 
 crystals, or of crystalline grains. 
 
 Explanations of Terms. 
 
 The following are explanations of a few terms used in connection 
 with this subject: 
 
 1. Octahedron.—A solid bounded by eight equal triangles. They are 
 equal equilateral triangles in the regular octahedron (Fig. 2, p. 17); 
 equal isosceles triangles in the square octahedron (Fig. 17, p. 82) ; equal 
 inequilateral triangles in the rhombic octahedron (Fig. 8, p. 37). 
 
 2. Double six-sided pyramids. Double eight-sided pyramids. Double 
 twelve-sided pyramids.—Solids made of two equal equilateral six-sided, 
 or eight-sided, or twelve-sided, pyramids placed base to base (Fig. 20, 
 p. 82, and 6, 10, pp. 46, 47). 
 
 3. Right prisms. Oblique prisms.—Right prisms are those that are 
 erect, all their sides being at right angles to the base. When inclined, 
 they are called oblique prisms. 
 
 4. Interfacial angle.—Angle of inclination between two faces or planes. 
 
 5. Similar planes. Similar angles.—The lateral faces of a square 
 prism (Fig. 2, p. 14) are equal and have like relations to the axes, and 
 hence they are said to be similar. Solid angles are similar when the 
 plane angles are equal each for each, and the enclosing planes are sey- 
 erally similar in their relations to the axes. 
 
 6. Truncated. Bevelled.—An edge of acrystal is said to be truncated 
 when it is replaced by a plane equally inclined to the enclosing planes, 
 ag in Fig. 18, p. 19; and it is bevelled when replaced by two planes 
 
 + 
 
CRYSTALLOGRAPHY. 9 
 
 equally inclined severally to the adjoining faces. Only edges that are 
 formed by the meeting of two similar planes can be truncated or bev- 
 elled. The angle between the truncating plane and the plane adjoining 
 it on either side always equals 90° plus half the interfacial angle over 
 the truncated edge. When a rectangular edge, or one of 90°, is trun- 
 cated, this angle is accordingly 135° (=90°+45°); when an edge of 70°, 
 it is 125° (—90° + 85°); when an edge of 140°, it is 160° (=90° + 70°). 
 
 ‘7 Zone.—A zone of planes includes a series of planes having the 
 edges between them, that is, their mutual intersections, all parallel. 
 Thus in Fig. 14, on page 6, O at top of figure, 72, 23, O in front, and 
 two planes below, and others on the back of the crystal are in one zone, 
 a vertical zone. Again, in the same figure, O at top, 42, 33, 22, 42, #2, 42, 
 22, 3, and the continuation of this series below and over the back of 
 the crystal lie in another vertical zone. And so in other cases, in 
 other directions. All planes in the same zone may be viewed as on the 
 circumference of the same circle. The planes of crystals are generally 
 all comprised in a few zones, and the study of the mathematics of 
 crystals is largely the study of zones of planes. 
 
 ‘Aves, —Imaginary lines in crystals intersecting one another at their 
 centres. Axes are assumed in order to describe the positions of the 
 planes of crystals. In each system of crystallization there is one vertt- 
 cal axis, and in all but hexagonal forms there are two lateral axes. 
 
 Diametral sections. —The sections of crystals in which lie any two of 
 the axes. In forms having two lateral axes, there are two vertical 
 diametral sections and one basal. 
 
 Diametral-prisms.—Prisms whose sides are parallel to the diametral 
 sections. 
 
 Measurement of Angles. 
 
 The angles of crystals are measured by means of instruments called 
 goniometers. ‘These instruments are of two kinds, one the common 
 goniometer, the other, the reflecting goniometer. 
 
 The common goniometer depends for its use on the very simple prin- 
 ciple that when two straight lines cross one an- 
 
 other, as A H, C D, in the annexed figure, the parts 
 will diverge equally on opposite sides of the point 
 of intersection (O); that is in mathematical lan- a 0 = 
 
 guage, the angle A O Dis equal to the angle C O H, 
 and A OC is equal to DO E. 
 
 A common form of the instrument is represented in the figure on 
 page 10. ; 
 
 The two arms @ 0, ed, move on a pivot at 0, and their divergence, 
 or the angle they make with one another, is read off on the graduated 
 arc attached. In using it, press up between the edges a@ o and ¢ 9, 
 the edge of the crystal whose angle is to be measured, and con- 
 tinue thus opening the arms until these edges lie evenly against the 
 faces that include the required angle. To insure accuracy in this 
 respect, hold the instrument and crystal between the eye and the light, 
 and observe that no light passes between the arm and the applied faces 
 of the crystal. The arms may then be secured in position by tighten- 
 ing the screw at 0 ; the angle will then be measured by the distance on 
 the arc from & to the lft or outer edge of the arm ¢ d, this edge being 1n 
 the line of 0, the centre of motion, As the instrument stands in the 
 
10 ORYSTALLOGRAPHY. 
 
 figure, it reads 45°. The arms have slits at g h, n p, by which the parts 
 &@ 0, ¢€0, may be shortened so as to make them more convenient for 
 measuring small crystals. 
 
 In the best form of the common goniometer the are is a complete 
 
 b 
 
 Al 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 circle, of larger diameter than in the above figure, and the arms are 
 separate from it. After making the measurement, the arms are laid 
 upon the circle, with the pivot at the centre of motion inserted in a 
 socket at the centre of the circle. The inner edge of one of the arms 
 is then brought to zero on the circle, and the angle is read off as before. 
 
 With a little ingenuity the student may construct a goniometer for 
 himself that will answer a good purpose. A semicircle may be de- 
 scribed on mica or a glazed card, and graduated. The arms might also 
 be made of stiff card for temporary use; but mica, bone, or metal is 
 better. The arms should have the edges straight and accurately paral- 
 lel, and be pivoted together. The instrument may be used like that last 
 described, and will give approximate results, sufficiently near for dis- 
 tinguishing most minerals. The ivory rule accompanying boxes of 
 mathematical instruments, having upon it a scale of sines for measuring 
 angles, will answer an excellent purpose, and is as convenient as the arc. 
 
 In making such measurements it is important to have in mind the 
 fact that— 
 
 1. The sum of the angles about a centre is 360°. 
 
 2. In a rhomb, as in a square, the sum of the plane angles is 360°. 
 
 In any polygon, the supplements of the angles equals 360°, whatever 
 the number of sides. For example: in a square, the four angles are 
 each 90°, and hence the supplements are 90°, and 4x 90=360; again, 
 in a regular hexagon the six angles are each 120, the supplements are 
 60°, and 6 x 60=360. So for all polygons, whether regular or irregular. 
 In measuring the angles it is therefore convenient to take down tha 
 supplements of the angles. This principle is conveniently applied in 
 the measurement of all the angles of a zone of planes around the 
 crystal; for the sum of all the supplements should be, as above, 360° ; 
 and if this result is not obtained there is error somewhere, 
 
ORYSTALLOGRAPHY. 11 
 
 The reflecting goniometer affords a _ more accurate method of 
 measuring crystals that have lustre, and may be used with those of 
 minute size. The principle on which this instrument is constructed 
 will be understood from the annexed figure, representing a crystal, 
 whose angle ab cis required. The eye, look- 
 ing at the face of the crystal bc, observes a 
 reflected image of m, in the direction P 7. On 
 revolving the crystal till a } has the position of 
 bc, the same image will be seen again in the 
 same direction Pn. As the crystal is turned, 
 in this revolution, till a 6 d has the present 
 position of 0 ¢, the angle d ) c measures the number of degrees through 
 which it isrevolved. But dd ¢ subtracted from 180° equals the angle 
 of the crystaladc. The crystal is therefore passed, in its revolution, 
 through a number of degrees equal to the supplement of the required 
 angle. 
 
 This angle, in the reflecting goniometer of Wollaston, is measured 
 by attaching the crystal to a graduated circle which revolves with it, 
 one form of which is here represented. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Cis the graduated circle. The wheel, m, is attached to the main 
 axis, and moves the graduated circle together with the adjusted crystal. 
 
12 ORYSTALLOGRAPIY. 
 
 The wheel, », is connected with an axis which passes through the 
 main axis (which is hollow for the purpose), and moves merely the 
 parts to which the crystal is attached, in order to assist in its adjust- 
 ment. The contrivances for the adjustment of the crystal are at a, ), 
 c, d,k. The screws, c, d, are for the adjustment of the crystal, and the 
 slides, a, 6, serve to centre it. 
 
 To use the instrument, it may be put on a stand or small table, with 
 its base accurately horizontal, and the table placed in front of a win- 
 dow, six to twelve feet off, with the plane of its circle at right angles 
 to the window. A dark line must then be drawn below the window, 
 near the floor, parallel to the bars of the window, and about as far 
 from the eye as from the window-bar. 
 
 The crystal is attached to the movable plate & by means of wax, and 
 so arranged that the edge of intersection of the two planes forming the 
 required angle, shall be in a line with the axis of the instrument. 
 This is done by varying its situation on the plate, or by means of the 
 adjacent screws and slides. 
 
 When apparently adjusted, the eye must be brought close to the 
 crystal, nearly in contact with it, and on looking into a face, part of 
 the window will be seen reflected, one bar of which must be selected 
 tor the trial. If the crystal is correctly adjusted, the selected bar 
 will appear horizontal, and on turning the wheel %, till this bar, as 
 reflected, is observed to approach the dark line below seen in a direct 
 view, it will be found to be parallel to this dark line, and ultimatély to 
 coincide with it. The eye for both observations should be held in 
 precisely the same position. If there is not a perfect coincidence, the 
 adjustment must be altered until this coincidence is obtained. Con- 
 tinue then the revolution of the wheel , till the same bar is seen by 
 reflection in the next face, and if here there is also a coincidence of 
 the reflected bar with the dark line seen direct, the adjustment is com- 
 plete ; if not, alterations must be made, and the first face again tried. 
 In an instrument like the one figured, the circle is usually graduated 
 to twenty or thirty minutes, and, by means of the vernier, minutes and 
 half minutes are measured. After adjustment, 180° on the arc must 
 be brought opposite 0, on the vernier, ». The coincidence of the bar 
 and dark line is then to be obtained, by turning the wheel ». When 
 obtained, the wheel m should be turned until the same coincidence is 
 observed, by means of the next face of the crystal. If a line on the 
 graduated circle now corresponds with 0 on the vernier, the angle is 
 immediately determined by the number of degrees opposite this line. 
 If no line corresponds with 0, we must observe which line on the 
 vernier coincides with one on the circle. If it is the 18th on the 
 vernier, and the line on the circle next below 0 on the vernier marks 
 125°, the required angle is 125° 18’; if this latter line marks 125° 20, 
 the required angle is 125° 88’. 
 
 In the better instruments other improved methods of arrangement 
 are employed; and in the best, often called Mitscherlich’s goniometer, 
 because first devised by him, there are two telescopes, one for passing 
 a ray of light upon the adjusted crystal, having crossed hair lines in its 
 focus, and the other for viewing it, also with a hair cross. With such 
 an arrangement, the window-bar and dark line are unnecessary, the 
 hair crosses serving to fix the position of the crystal, and the telescope 
 that of the eye. If the crystal is perfect in its planes, and the adjust- 
 
CRYSTALLOGRAPHY. 15 
 
 ment exact, the measurement, with the best instruments, will give the 
 angle within 10”. 
 
 Other goniometers have only the second of the two telescopes just 
 alluded to, as is the case in the figure on page 11. This telescope gives 
 a fixed position to the eye ; and through it is seen a reflection of some 
 distant object, which may be even a chimney-top. For the measure- 
 ment the object, seen reflected in the two planes successively, is 
 brought each time into conjunction with the hair cross. Exact adjust- 
 ment is absolutely essential, and with an instrument having the two 
 telescopes, the first step in a measurement cannot be taken without it. 
 
 Only small, well-polished crystals can be accurately measured by the 
 reflecting goniometer. Tf, when using the instrument without tele- 
 scopes, the faces do not reflect distinctly a bar of the window, the flame 
 of a candle or of a gas-burner, placed at some distance from the crystal, 
 may be used by observing the flash from it with the faces in succession 
 as the circle isrevolved. A ray of sun-light from a mirror, received on 
 the crystal through a small hole, may be employed ina similar way. But 
 the results of such measurements will be only approximations. With 
 two telescopes and artificial light, and with a cross slit to let the light 
 pass in place of the cross hairs of the first of the above-mentioned tele- 
 scopes, this light cross will be reflected from the face of a crystal even 
 when it is not perfect in polish, and quite good results may be obtained. 
 
 B. Srructure.—Structure includes cleavage, a characteristic 
 of crystals intimately connected with their forms and nature. 
 It is the property, which many crystals have, of admitting of 
 subdivision indefinitely in certain directions, and affording 
 usually even, and frequently polished, surfaces. The direction 
 is always parallel with the planes of the axes, or with others 
 diagonal to these. 
 
 The ease with which cleavage can be obtained varies greatly 
 in different minerals, and in different directions in the same 
 mineral. In a few species, like mica, it readily yields laminz 
 thinner than paper, and in this case the cleavage is said to be 
 eminent. Others, of perfect cleavage, cleave easily, but afford 
 thicker plates, and from this stage there are all grades to that 
 in which cleavage is barely discernible or dificult. The cleav- 
 age surfaces vary in lustre from the most brilliant to those that 
 are nearly dull. When cleavage in a mineral is alike in two or 
 more directions, that is, is attainable in these directions with 
 equal facility and affords surfaces of like lustre and character 
 or marking, this is proof that the planes in those directions are 
 similar, or have similar relations to like axes. For example, 
 equal cleavage in three directions, at right angles to one another, 
 shows that the planes of cleavage correspond to the faces of the 
 cube; so equal cleavage in two directions, in a prismatic min- 
 eral, shows that the planes in the two directions are those of a 
 
14 CRYSTALLOGRAPHY. 
 
 square prism, or else of a rhombic prism; and if they are at 
 right angles to one another that they are those of the former. 
 This subject is further illustrated beyond. 
 
 In the following pages (1) the Systems of Crystallization and 
 the Forms and Structure of Crystals are first considered ; next, 
 (2) Compound, or Twin Crystals; and then (3) Crystalline 
 A geregates. 
 
 1. SYSTEMS OF CRYSTALLIZATION: FORMS 
 AND STRUCTURE OF CRYSTALS. 
 
 The forms of crystals are exceedingly various, while the sys- 
 tems of crystallization, based on their mathematical distinctions, 
 are only six in number. Some of the simplest of the forms 
 under these six systems are the prisms represented in the fol- 
 lowing figures; and by a study of these forms the distinctions 
 
 
 
 of the six systems will become apparent. These prisms are all 
 four-sided, excepting the last, which is six-sided. In them the 
 planes of the top and bottom, and any planes that might be 
 made parallel to these, are called the basal planes, and the sides 
 the lateral planes. An imaginary line joining the centres of 
 the bases (c in figures 1 to 8) is called the vertical amis, and the 
 
. SYSTEMS OF CRYSTALLIZATION. 15 
 
 diagonals a and b, drawn in a plane parallel to the base, are the 
 lateral aces. ™ 
 
 Fig. 1 represents a cube. It has all its planes square (like 
 fig. 9), and all its plane and solid angles, right angles, and the 
 three axes consequently cross at right angles (or, in other 
 
 me <>< 
 
 words, make rectangular intersections) and are equal. It is an 
 example under the first of the systems of crystallization, which 
 system, in allusion to the equality of the axes, 1s called the 
 Isometric system, from the Greek for equal and measure. 
 
 Fig. 2 represents an erect or right square prism having all its 
 plane angles and solid angles rectangular. The base is square 
 or a tetragon, and consequently the lateral axes are equal and 
 rectangular in ther intersections ; but, unlike a cube, the verti- 
 cal axis is unequal to the lateral, There are hence, in the square 
 prism, axes of two kinds making rectangular intersections. The 
 system is hence called, in allusion to the two kinds of axes, the 
 Dimetric system, or, in allusion to the tetragonal base, the 7'e- 
 tragonal system. 
 
 Fig. 3 represents an erect or right rectangular prism, in 
 which, also, the plane angles and solid angles are rectangular. 
 The base is a rectangle (fig. 10), and consequently the lateral 
 axes, connecting the centres of the opposite lateral faces, are wn- 
 equal and rectangular in their intersections; and, at the same 
 time, each is unequal to the vertical. There are hence three 
 unlike axes making rectangular intersections; and in allusion 
 to the three unlike axes, the system is called the Trimetrve sys- 
 tem. It is also named, in allusion to its including erect prisms 
 having a rhombic base, the Orthorhombic system, orthos, in 
 
 Greek, signifying straight or erect. 
 
 This rhombic prism is represented in fig. 4, It has a rhom- 
 bic base, like fig. 11; the lateral axes connect the centres of the 
 opposite lateral edges; and hence they cross at right angles and 
 are unequal, as in the rectangular prism. This right rhombic 
 prism is therefore one in system with the right rectangular 
 prism. 
 
 Fig. 5 represents another rectangular prism, and fig. 6 
 
16 CRYSTALLOGRAPIY. 
 
 another rhombic prism; but, unlike figs. 3 and 4, the prisms are 
 inclined backward, and are therefore oblique prisms. The lat- 
 eral axes (a, 6) are at right angles to one another and unequal, 
 as in the preceding system; but the vertical axis is inclined to 
 the plane of the lateral axes. Tt is inclined, however, to only 
 one of the lateral axes, it being at right angles to the other. 
 Hence, of the three angles of axial intersection, two are rec- 
 tangular, namely w on 0, and ¢ on b, while one is oblique, that 1s 
 c (the vertical axis) on a. In allusion to this fact, there being 
 only one oblique angle, this system is called the Monoclinic sys- 
 tem, from the Greek for one and inclined. 
 
 Fig. 7 represents an oblique prism with a rhomboidal base 
 (like fig. 12). The three axes are unequal and the three axial 
 intersections are all oblique. The system is called the Triclinie 
 system, from the Greek for three and «inclined. 
 
 Fig. 8 represents a six-sided prism, with the sides equal, and 
 the base a regular hexagon. The lateral axes are here three in 
 number. ‘They intersect at angles of 60°; and this is so, 
 whether these lateral axes be lines joining the centres of oppo- 
 site lateral planes, or of opposite lateral edges, as a trial will 
 show. The vertical axis is at right angles to the plane of the 
 three lateral axes, inasmuch as the prism 1s erect or right. The 
 base of the prism being a regular hexagon, the system is called 
 the Hexagonal system. 
 
 The systems of crystallization are therefore : 
 
 I. The Isomerric system: the three axes rectangular in in- 
 tersections ; equal. : 
 
 Il. The Dimerric or TETRAGONAL system: the three axes 
 rectangular in intersections; the two lateral axes equal, and 
 unequal to the vertical. 
 
 ILL. ‘The Trimerric or OnTHORHOMBIC system: the three axes 
 rectangular in intersections, and unequal. 
 
 IV. The Monociinic system: only one oblique inclination 
 out of the three made by the intersecting axes; the three axes 
 unequal. 
 
 V. The Trictrnic system : all the three axes obliquely inclined 
 to one another, and unequal. 
 
 VI. The HEXAGONAL system: the vertical axis at right angles 
 to the lateral; the lateral three in number, and intersecting at 
 angles of 60°. : 
 
 These six systems of crystallization are based on mathemati- 
 cal distinctions, and the recognition of them 1s of great value 
 in the study and description of crystals. Yet these distinctions 
 are often of feeble importance, since they sometimes separate 
 
SYSTEMS OF CRYSTALLIZATION. 17 
 
 species and crystalline forms that are very close in their rela- 
 tions. There are forms under each of the.systems that differ 
 put little in angles from some of other systems : for example, 
 square prisms that vary but slightiy from the cubic form ; tr1- 
 clinic that are almost identical with monoclinic forms ; hexa- 
 gonal that are nearly cubic. Consequently it is found that the 
 same natural group of minerals may include both trimetric and 
 monoclinic species, as is true of the Hornblende group; or 
 monoclinic and triclinic, as is the fact with the F eldspar group, 
 and so on. It is hence a point to be remembered, when the 
 affinities of species are under consideration, that difference in 
 crystallographic system is far from certain evidence that any 
 species are fundamentally or widely unlike. 
 
 I. THE ISOMETRIC SYSTEM. 
 
 1. Descriptions of Forms, The following are figures of some 
 of the forms of crystals under the isometric system : 
 
 
 
 The first is the cube or hexahedron, already described. Be- 
 sides the three cubic axes, there are equal diagonals in two 
 other directions; one set connecting the apices of the diago- 
 nally opposite solid angles, four in number (because the number 
 of such angles is eight), and called the octahedral axes ; and 
 another set connecting the centres of the diagonally opposite 
 
 2 
 
18 CRYSTALLOGRAPHY. 
 
 edges, siz in number (because the number of edges is twelve), 
 and called the dodecahedral axes. 
 
 Fig. 2 represents the octahedron, a solid contained under 
 eight equal triangular faces (whence the name from the Greek 
 eight and face), and having the three axes like those in the cube. 
 Its plane angles are 60°; its interfacial angles, that is the incli- 
 nation of planes 1 and 1 over an intervening edge, 109° 28’ ; 
 and 1 on | over a solid angle, 70° 32’. 
 
 Fig. 3 is the dodecahedron, a solid contained under twelve 
 equal rhombic faces (whence the name from the Greek for twelve 
 and face). ‘The position of the cubic axes is shown in the fig- 
 ure. It has fourteen solid angles; six formed by the meeting of 
 four planes, and eight formed by the meeting of three. The 
 interfacial angles (or ¢ on an adjoining 7) are 120°; 7 on a over 
 a four-faced solid angle =90°. 
 
 Fig. 4 is a trapezohedron, a solid contained under 24 equal 
 trapezoidal faces. There are several different trapezohedrons 
 among isometric crystalline forms. The one here figured, which 
 is the common one, has the angle over the edge B, 131° 49’, 
 and that over the edge C, 146° 27’. A trapezohedron is also 
 called a tetragonal trisoetahedron, the faces being tetragonal 
 or four-sided, and the number of faces being 3 times 8 (éris, 
 octo, in Greek). 
 
 Fig. 5 is another trisoctahedron, one having trigonal or three- 
 sided faces, and hence called a trigonal trisoctahedron. Com- 
 paring it with the octahedron, fig. 2, it will be seen that three 
 of its planes correspond to one of the octahedron. The same is 
 true also of the trapezohedron. 
 
 Fig. 6 is a tetrahewahedron, that is a 4x 6-faced solid, the 
 faces being 24 in number, and four corresponding to each face 
 of the cube or hexahedron (fig. 1). 
 
 Fig. 7 is a hexoctahedron, that is a 6 x 8-faced solid, a pyramid 
 of six planes corresponding to each face in the octahedron, as 1s 
 apparent on comparison. ‘There are different kinds of hexocta- 
 hedrons known among crystallized isometric species, as well as 
 of the two preceding forms. In each case the difference is not 
 in number or general arrangement of planes, but in the angles 
 between the planes, as explained beyond. 
 
 But these simple forms very commonly occur in combination 
 with one another ; a cube with the planes of an octahedron and 
 the reverse, or with the planes of any or all of the other kinds 
 above figured, and many others besides. Moreover, all stages 
 between the different forms are often represented among the 
 crystals of a species. Thus between the cube and octahedron, 
 
ISOMETRIC SYSTEM. 19 
 
 occur the forms shown in figs. 8 to 11. Fig. 12 is a cube; 
 fig. 8 represents the cube with a plane on each angle, equally 
 inclined to each cubic face; 9, the same, with the planes on the 
 angles more enlarged and the cubic faces reduced in size ; and 
 
 
 
 then 10, the octahedron, with the cubic faces quite small ; 
 and fig. 11, the octahedron, the cubic faces having disappeared 
 altogether. This transformation is easily performed by the 
 student with cubes cut out of chalk, clay, ora potato. It shows 
 the fact that the cubic axes (fig. 12) connect the apices of the 
 solid angles in the octahedron. 
 
 Again, between a cube and a dodecahedron there occur forms 
 like figs. 13 and 14; fig. 12 being a cube, fig. 13 the same, with 
 planes truncating the edges, each plane being equally inclined 
 to the adjacent cubic faces, and fig. 14 another, with these 
 planes on the edges large and the cubic faces small ; and then, 
 when the cubic faces disappear by farther enlargement of the 
 planes on the edges, the form is a dodecahedron, tig. 1D. ihe 
 student should prove this transformation by trial with chalk or 
 some other material, and so for other cases mentioned beyond. 
 The surface of such models in chalk may be made hard by a 
 coat of mucilage or varnish. 
 
 Again, between a cube and a trapezohedron there are the 
 forms 17 and 18; 16 being the cube, 17, cube with three planes 
 placed symmetrically on each angle; 18, the same with the 
 cubic faces greatly reduced (but also with small octahedral faces), 
 and 19, the trapezohedron, the cubic faces having disappeared. 
 
90 CRYSTALLOGRAPHY. 
 
 Again, fig. 20 represents a cube with three planes on each 
 angle, which, if enlarged to the obliteration of the faces of the 
 cube, become the trigonal trisoctahedron, fig. 21. So again, fig. 
 
 
 
 22 represents a cube with six faces on each angle, which, if en- 
 larged to the same extent as in the last, would become the hex- 
 octahedron, fig. 23. 
 
 Again, fig. 25 is a form between the octahedron (fig. 24) and 
 
 
 
 dodecahedron (fig. 26); and figs. 27 and 28 are forms between 
 the dodecahedron, fig. 26, and trapezohedron, fig. 29. 
 
ISOMETRIC SYSTEM. a1 
 
 Again, fig. 30 is a form between a cube (fig. 16) and a tetra- 
 hexahedron, fig. 31; fig. 32, a form between an octahedron, fig. 
 24, and a tetrahexahedron, fig. 31; fig. 33, a form between an 
 
 30. 
 
 
 
 octahedron and a trigonal trisoctahedron, fig. 34; fig. 35, a form 
 between a dodecahedron (planes 7) and a tetrahexahedron ; fig. 
 
 
 
 36, a form between the dodecahedron and a hexoctahedron, 
 
 fig. 37. 
 Fig. 38 represents a cube with planes of both the octahedron 
 
 and dodecahedron. 
 
 2. Positions of planes with reference to the axes. Lettering 
 of figures.—The numbers by which the planes in the above figures, 
 and others of the work, are lettered, indicate the positions of the planes 
 with reference to the axes, and exhibit the mathematical symmetry 
 and ratios in crystallization. In the figure of the cube (fig. 1) the three 
 axes are represented; the lateral semi-axis which meets the front 
 planes in the figure is lettered a; that meeting the side plane to the 
 right 5, and the vertical axis ¢, and the other halves of the same axes 
 respectively -a, -), -c. By a study of the positions of the planes of the 
 
99 CRYSTALLOGRAPHY. 
 
 cube and other forms with reference to these axes, the following facts 
 will become apparent. 
 
 In the cube (fig. 1) the front plane touches the extremity of axis a, 
 but is parallel to axes b andc. When one line or plane is parallel to 
 another they do not meet except at an infinite distance, and hence the 
 sign for infinity is used to express parallelism. Employing 7, the 
 initial of infinity, as this sign, and writing c, 0, a, for the semi-axes so 
 lettered, then the position of this plane of the cube is indicated by the 
 expression ic: 7): la. The top and side-planes of the cube meet one 
 axis and are parallel to the other two, and the same expression answers 
 for each, if only the letters a, b, c, be changed to correspond with their 
 positions. The opposite planes have the same expressions, except that 
 the c, 6, a will refer to the opposite halves of the axes and be -c, -d, -a. 
 
 In the dodecahedron, fig. 15, the right of the two vertical front planes 
 ¢. meets two axes, the axes a and 3, at their extremities, and is parallel 
 to the axisc. Hence the position of this plane is expressed by tc : 10: 1a. 
 So, all the planes meet two axes similarly and are parallel to the third. 
 The expression answers as well for the planes @ in figs. 13, 14, as for that 
 of the dodecahedron, for the planes have all the same relation to the axes, 
 
 In the octahedron, fig. 11, the face 1, situated to the right above, 
 like all the rest, meets the axes a, 0, ¢, at their extremities; so that the 
 expression 1c : 10: 1a answers for all. 
 
 Again, in fig. 17 (p. 20) there are three planes, 2-2, placed symmet- 
 rically on each angle of a cube, and, as has been illustrated, these are 
 the planes of the trapezohedron, fig. 19. The upper one of the planes 
 2-2 in these figures, when extended to meet the axes (as in fig. 19), 
 intersects the vertical ¢ at its extremity, and the others, @ and 0, at 
 twice their lengths from the centre. Hence the expression for the plane 
 is 1c: 20: 2a. So, as will be found, the left hand plane 2-2 on fig. 
 17, will have the expression 2¢: 10: 2a; and the right hand one, 
 2c: 2b:1a. Further, the same ratio, by a change of the letters for the 
 semi-axes, will answer for all the planes of the trapezohedron. 
 
 In fig. 20 there are other three planes, 2, on each of the angles of a 
 cube, and these are the planes of the trisoctahedron in fig. 21. The 
 lower one of the three on the upper front solid angle, would meet if 
 extended, the extremities of the axes a@ and 0, while it would meet the 
 vertical axis at twice its length from the centre. The expression 
 2c: 1b: 1a indicates, therefore, the position of the plane. So also, 
 le: 1b: 2aand 1c: 20: 1a represent the positions of the other two 
 planes adjoining; and corresponding expressions may be similarly ob- 
 tained for all the planes of the trisoctahedron. 
 
 Again, in fig. 80, of the cube with two planes on each edge, and in 
 fig. 81, of the tetrahexahedron bounded by these same planes, the left 
 of the two planes in the front vertical edge of fig. 30 (or the corre- 
 sponding plane on fig. 31) is parallel to the vertical axis ; its intersections 
 with the lateral axes, a and 4, are at unequal distances from the centre, 
 expressed by the ratio 2): 1a. This ratio for the plane adjoining on 
 the right is 1): 2a. The position of the former is expressed by the 
 ratio tc : 2b: 1a, and for the other by tc: 10: 2a. Thus, for each of 
 the planes of this tetrahexahedron the ratio between two axes is 1 : 2, 
 while the plane is parallel to the third axis. 
 
 Again, in fig. 22, of the cube with six planes on each solid angle, and 
 in the hexoctahedron in fig. 23, made up of such planes, each of the 
 planes when extended so that it will meet one axis at once its length 
 
ISOMETRIC SYSTEM. 93 
 
 from the centre, will meet the other axes at distances expressed by a 
 constant ratio, and the expression for the lower right one of the six 
 planes will be 8c: $d: 1a. By a little study, the expressions for the 
 other five adjoining planes can be obtained, and so also those for all the 
 48 planes of the solid. 
 
 In the isometric system the axes a, b, ¢, are equal, so that in the 
 general expressions for the planes these letters may be omitted; the 
 expressions for the above mentioned forms thus become— 
 
 Cube (fig. 1), ¢: 1: #. Tetrahexahedron (fig. 5), ¢: 1: 2. 
 Octahedron (fig. 2), 1: 1:1. Trigonal trisoctahedron (fig. 6), 
 Dodecahedron (fig. 3), 1:1: 4%. ea aaa | 
 
 Trapezohedron (fig. 4), 2: Tee Hexoctahedron (fig. 7), 3:1: 3. 
 
 Looking again at fig. 17, representing the cube with planes of the trap- 
 ezohedron, 2:1: 2, it will be perceived that there might be a trap- 
 ezohedron having the ratios 14:1:14, 3: 15s Bt Aas AOS s As By 
 and others; and, in fact, such trapezohedrons occur among crystals. 
 So also, besides the trigonal trisoctahedron 2:1:1 (fig. 21), there 
 might be, and there in fact is, another corresponding to the expression 
 8:1:1; and still others are possible. And besides the hexoctahedron 
 3:1: 4% (fig. 23), there are others having the ratios 4: 1: 2, Ares 
 5:1:%,andsoon — 
 
 In the above ratios, the number for one of the lateral axes is always 
 made a unit, since only a ratio is expressed; omitting this in the ex- 
 pression, the above general ratios become: for the cube, 4: ¢; for the 
 octahedron, 1:1; dodecahedron, 1:4; trapezohedron, 2: 2; tetra- 
 hexahedron, ¢: 2; trigonal-trisoctahedron, 2:1; and hexoctahedron, 
 3:3. In the lettering of the figures these ratios are put on the planes, 
 but with the second figure, or that referring to the vertical axis, first. 
 Thus the lettering on the hexoctahedron (fig. 23), is 8-3; onthe trigonal 
 trisoctahedron (fig. 21) is 2, the figure 1 being unnecessary ; on the 
 tetrahexahedron (fig. 31), 7-2; on the trapezohedron (figs. 4 and 19), 
 2-2; on the dodecahedron (fig. 15), 7; on the octahedron, 1; on the 
 cube, 7-7, in place of which H is used, the initial of hexahedron. In the 
 printed page these symbols are written with a hyphen in order to avoid 
 occasional ambiguity, thus 3-3, j-2, 2-2, etc. Similarly, the ratios 
 for all planes, whatever they are, may be written. The numbers are 
 usually small, and never decimal fractions. 
 
 The angle between the planes $-2 (ort: 1: 2) and O, in fig. 30, page 
 21, may be easily calculated, and the same for any plane of the series 
 i-n(¢:1:%). Draw the right-angled triangle, A DG, 
 as in the annexed figure, making the vertical side, 
 OD, twice that of AC, the base; that is, give them 
 the same ratio as in the axial ratio for the plane. If 
 AC=1. UD=2. Then, by trigonometry, making 
 AC the radius, 1: R::2: tan DAC; or 1: B::2: cob 
 ADG. Whence tan DAC = cot ADCs 2. wbyenu- 
 ding to 90°, the angle of the triangle obtained by work- 
 ing the equation, we have the inclination of the basal 
 plane O, or the O on the opposite side of the plane i-2, 
 (faces of the cube) on the plane 7-2. So in all cases, 
 whatever the value of 7, that value equals the tangent 
 of the basal angle of the triangle (or the cotangent of the angle at the 
 vertex), and from this the inclination to the cubic faces is directly ob- 
 
 
 
24 ‘ORYSTALLOGRAPHY. 
 
 i. 
 
 tained by adding 90°. If » =1, then the ratio is 1:1, as in ACB, 
 and each angle equals 45°, giving 185° for the inclination on either 
 adjoining cubic face. 
 
 Again, if the angles of inclination have been obtained by measure- 
 ment, the value of n in any case may be found by reversing the above 
 calculation ; subtracting 90° from the angle, then the tangent of this 
 angle, or the cotangent of its supplement, will equal 7, the tangents 
 varying directly with the value of n, 
 
 In the case of planes of the m: 1:1 series (including1:1:1, 2: 1: 
 1, etc.), the tangents of the angle between a cubic face in the same 
 zone and these planes, less 90°, varies with the value of m. In the 
 case of the plane 1 (or 1:1: 1), the angle between it and the cubic face 
 is 125° 16’. Subtracting 90°, we have 35° 16’. Draw a right-angled 
 
 triangle, OBC, with 35° 10’ as its vertex angle. BC has 
 
 y) the value of 1c, or the semi-axis of the cube. Make 
 
 DC=2BC. Then, while the angle OBC has the value 
 
 of the inclination on the cubic face less 90° for the plane 
 
 1:1:1, ODOC has the same for the plane 2:1: 1. Now, 
 
 making OC the radius, and taking it as unity, BC is the 
 
 B tangentof BOC, or cot OBC’. SoDC= 2BC is the tan- 
 
 gent of DOC, or cot ODC. By lengthening the side CD 
 
 (= 2BC or 2c) it may be made equal to 83BC =3e, its 
 
 value in the case of the plane 38:1:1; or to4BC = 4e, 
 
 its value in the case of the plane 4: 1:1; or mBC=me 
 
 0 C for any plane in the series m:1:1; and since in all 
 
 there will be the same relation between the vertical and 
 
 the tangent of the angle at the base (or the cotangent of the angle at 
 
 the vertex), it follows that the tangent varies with the value of m. 
 
 Hence, knowing the value of the angle in the case of the form 1 
 (1: 1:1), the others are easily calculated from it. 
 
 BO being a unit, the actual value of OC is $ 2, or 1/4, it being half the 
 diagonal of a square, the sides of which are 1, and from this value the 
 angle 35° 16’ might be obtained for the angle OBC. 
 
 The above law (that for a plane of the m: 1: 1 series, the tangent of 
 its inclination on a cubic face lying in the same zone, less 90°, varies 
 with the value of m, and that it may be calculated for any plane 
 m:1:1 from this inclination in the form 1:1: 1), holds also for 
 planes in the series m:2:1, or m:3: 1, or anym:n:1. That is, 
 given the inclination of O on 1:7: 1, its tangent doubled will be that 
 of 2: 2:1, or trebled, that of 3: 2:1, and so on, or halved, it will be 
 that of the plane +: 2: 1, which expression is essentially the same as 
 een 2: 
 
 These examples show some of the simpler methods of applying ma- 
 thematics in calculations under the isometric system. The values of 
 the axes are not required in them, because a=b=c=1. 
 
 8. Hemihedral Crystals—The forms of crystals described 
 above are called holohedral forms, from the Greek for all and 
 face, the number of planes being all that full symmetry re- 
 quires. The cube has eight similar solid angles—similar, that 
 is, in the enclosing planes and plane angles. Consequently the 
 law of full symmetry requires that ail should have the same 
 
ISOMETRIC SYSTEM. 95 
 
 planes and the same number of planes; and this is the general 
 law for all the forms. This is a consequence of the equality 
 of the axes and their rectangular intersections. 
 
 But in some crystalline forms there are only half the num- 
 ber of planes which full symmetry requires. In fig. 39 a cube 
 is represented with an octahedral plane on half, that is, four, of 
 
 39. 40. 41. 42. 
 
 — H- 
 
 IT 
 
 
 
 the solid angles. A solid angle having such a plane is diag- 
 onally opposite to one without it. The same form is represented 
 in fig. 40, only the cubic faces are the smallest; and in fig. 41 
 the simple form is shown which is made up of the four octahe- 
 dral planes. It is a tetrahedron or regular three-sided pyra- 
 tnid. Ifthe octahedral faces of fig. 39 had been on the other 
 four of the solid angles of the cube, the tetrahedron made of 
 those planes would have been that of fig. 42 instead of fig. 41. 
 Other hemihedral forms are represented in figs. 43 to AD: fig. 
 43 is a hemihedral form of the trapezohedron, fig. 2 aa et 
 
 
 
 fig. 44, hemihedral of the hexoctahedron, fig. 7, or a nemi-hex- 
 octahedron. Fig. 45 is a combination of the tetrahedron (plane 
 1) and hemi-hexoctahedron. 
 
 In these forms figs. 41-44, no face has another parallel to it; 
 and consequently they are called inclined hemrhedrons. 
 
 Fig. 46 represents a cube with the planes of a tetrahexahe- 
 dron, as already explained. In fig. 47, the cube has only one 
 of the planes 7-2 on each edge, and therefore only twelve in all; 
 
26 CRYSTALLOGRAPHY. 
 
 and hence it affords an example of hemihedrism—a kind that is 
 presented by many crystals of pyrite. Fig. 48 is the hemihe- 
 
 
 
 dral form resulting when these twelve planes 7-2 are extended 
 to the obliteration of the cubic faces; and fig. 49 is another, 
 made of the other twelve of these planes. Again, 
 in fig. 50, a cube is represented having only 
 three out of the six planes of fig. 22, and this 
 is another example of hemihedrism. These kinds 
 differ from the inclined hemihedrons in having 
 opposite parallel faces, and hence they are called 
 parallel hemihedrons. 
 
 
 
 4, Internal Structure of Isometric Crystals, or Cleavage.— 
 The crystals of many isometric minerais have cleavage, or 
 a greater or less capability of division in directions situated 
 symmetrically with reference to the axes. The cleavage direc- 
 tions are parallel either to the faces of the cube, the octahe- 
 dron, or the dodecahedron, In galenite (p. 145) there is easy 
 cleavage in three directions parallel to the faces of the cube ; 
 in fluorite (p. 208), in four directions parallel to the faces of the 
 octahedron ; in sphalerite (p. 154), in six directions parallel to 
 the faces uf the dodecahedron. These cleavages are an impor- 
 tant means of distinguishing the species. 
 
 The three cubic cleavages are precisely alike in the ease with 
 which cleavage takes place, and in the kinds of surface obtained ; 
 and so is it with the four in the octahedral directions, and the six 
 in the dodecahedral. Occasionally cleavages of two of these sys- 
 tems occur in the same mineral ; that is, for example, parallel to 
 both the faces of the cube and the octahedron ; but when so, 
 those of one system are much more distinct than those of the 
 other, and cleavage surfaces in the two directions are quite un- 
 like as to smoothness and lustre. 
 
 5. Irregularities of Isometric Crystals,—A cube has its faces — 
 _ precisely equal, and so it is with each of the forms represented 
 
ISOMETRIC SYSTEM. oF, 
 
 in figs. 2 to 7. This perfect symmetry is almost never found 
 in actual crystals. 
 
 52. 53. 
 
 
 
 A cubic crystal has generally the form of a square prism (fig. 
 51 a stout one, fig. 52 another long and slender), or a rectangu- 
 lar prism (fig. 53). In such cases the crystal may still be 
 known to be a cube; because, if so, the kind of surface and 
 kind of lustre on the six faces will be precisely alike; and if 
 there is cubic cleavage it will be exactly equal in facility in 
 three rectangular directions; or if there is cleavage in four, or 
 six, directions, it will be equal in degree in the four, or the six, 
 directions, and have mutual inclinations corresponding with the 
 angles of the octahedron or dodecahedron 5 and thus the crys- 
 tal will show that it is isometric in system. 
 
 The same shortening or lengthening of the crystal often dis- 
 
 
 
 guises greatly the octahedron, dodecahedron, and other forms. 
 This is illustrated in the following figures: Fig. 54 shows the 
 
28 CRYSTALLOGRAPHY. 
 
 form of the regular octahedron; 55, an octahedron lengthened 
 horizontally ; 56, one shortened parallel to one of the pairs 
 of faces; 57, one lengthened parallel to another pair, the 
 ultimate result of which obliterates two of the faces, and 
 places an acute solid angle in place of each. The solid is 
 then six-sided, and has rhombic faces whose plane angles are 
 120° and 60°. The following figures illustrate corresponding 
 changes in the dodecahedron (fig. 58). In fig. 59 the dodeca- 
 
 58. 59. 
 
 
 
 
 
 hedron is lengthened vertically, making a square prism with four- 
 sided pyramidal terminations. In 60, it is shortened vertically. 
 In 61 the dodecahedron is lengthened obliquely in the direction 
 of an octahedral axis, and in 62 it is shortened in the same 
 direction, making six-sided prisms with trihedral terminations. 
 
 So again in the trapezohedron there are equally deceptive 
 forms arising from elongations and shortenings in the same two 
 clirections. 
 
 These distortions change the relative sizes of planes, but not 
 the values of angles. In crystals of the several forms repre- 
 sented in figs. 54 to 57, the inclinations are the same as in the 
 regular octahedron. ‘There is the same constancy of angle in 
 other distorted crystals. 
 
SYSTEMS OF ORYSTALLIZATION. 29 
 
 Occasionally, as in the diamond, the planes of crystals are 
 convex; and then, of course, the angles will differ from the 
 true angle. It is important, in order to meet the difficulties in 
 the way of recognizing isometric crystals, to have clearly in the 
 mind the precise aspect of an equilateral triangle, which 1s the 
 shape of a face of an octahedron ; the form of the rhombic face 
 of the dodecahedron; and the form of the trapezoidal face of a 
 trapezohedron. With these distinctly remembered, isometric 
 crystalline forms that are much obscured by distortion, or which 
 show only two or three planes of the whole number, will often 
 be easily recognized. 
 
 Crystals in this system, as well as in the others, often have 
 their faces striated, or else rough with points. This is gener- 
 ally owing to a tendency in the forming crystal to make two 
 different planes at the same time, or rather an 
 oscillation between the condition necessary for 
 making one plane and that for making another. 
 Fig. 63 represents a cube of pyrite with stri- 
 ated faces. As the faces of a cube are equal, 
 thestriations are alike on all. It will be noted 
 that the striations of adjoining faces are at right 
 angles to one another. The little ridges of the 
 striated surfaces are made up of planes of the pentagonal dode- 
 cahedron (fig. 49, p. 26), and they arise from an oscillation in 
 the crystallizing conditions between that which, if acting alone, 
 would make a cube, and that which would make this hemihe- 
 dral dodecahedron. Again, in magnetite, oscillations between the 
 octahedron and dodecahedron produce the striations in fig. Gas 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 MAGNETITE. COMMON SALT. 
 
 Octahedral crystals of fluorite often occur with the faces 
 made up of evenly projecting solid angles of a cube, giving 
 
380 CRYSTALLOGRAPHY. 
 
 them rough instead of polished planes. This has arisen from 
 oscillation between octahedral and cubic conditions. 
 
 In some cases crystals are filled out only along the diagonal 
 planes. Fig. 65 represents a crystal of common salt of this 
 kind, having pyramidal depressions in place of the regular faces. 
 Octahedrons of gold sometimes occur with three-sided, pyram- 
 idal depressions in place of the octahedral faces. Such forms 
 sometimes result when crystals are eroded by any cause. 
 
 II. DIMETRIC, on TETRAGONAL SYSTEM. 
 
 1. Descriptions of Forms.—In this system (1) the axes cross at 
 right angles; (2) the vertical axis is either longer or shorter than 
 the lateral; and (3) the lateral axes are equal. 
 
 The following figures represent some of the crystalline forms. 
 They are very often attached by one extremity to the support- 
 
 
 
 IDOCRASE. APOPHYLLITE, ZIRCON. 
 
 ing rock and have perfect terminating planes only at the other. 
 Square prisms, with or without pyramidal terminations, square 
 octahedrons, eight-sided prisms, eight-sided pyramids, and espe- 
 cially combinations of these, are the common forms. Since the 
 lateral axes are equal, the four lateral planes of the square 
 prisms are alike in lustre and surface-markings. For the same 
 reason the symmetry of the crystal is throughout by fours; that 
 is, the number of similar pyramidal planes at the extremity is 
 either four or eight; and they show that they are similar by 
 
DIMETRIC, OR TETRAGONAL SYSTEM. 31 
 
 being exactly alike in inclination to the basal plane as well as 
 alike in lustre. 
 There are two distinct square prisms. In one (fig. 10) the 
 
 10. Buy 12. 
 
 
 
 axes connect the centres of the lateral faces. In the other 
 (tig. 12) they connect the centres of the lateral edges. In fig. 
 11 the two prisms are combined; the figure shows that the 
 planes of one truncate the lateral edges of the other, the inter- 
 facial angle between adjoining planes being 1307. igess, 
 4,7, are of others having planes of both prisms. In fig. 13 one 
 prism is represented within the other. 
 
 Fig. 14 represents an eight-sided prism, and fig. 15 a combi- 
 nation of a square prism (ii) with an eight-sided prism (7-2). 
 
 15. 
 
 
 
 Another example of this is shown in fig. 4, and also in, figs 9, 
 the planes 7-2 in one, and 7-3 in the other. 
 
 The basal plane in these prisms is an independent plane, be- 
 cause the vertical axis is not equal to the lateral, and hence it 
 almost always differs in lustre and smoothness from the lateral. 
 
 Like the square prisms, the square octahedrons are in two 
 series, one set (fig. 16) having the lateral or basal edges parallel 
 to the lateral axes, and these axes connecting the centres of 
 opposite basal edges, and the other (fig. 17) having them diago- 
 nal to the axes, these axes connecting the apices of the opposite 
 
o2 CRYSTALLOGRAPHY. 
 solid angles, as in the isometric octahedron. There may be, on 
 the same crystal, faces of several octahedrons of these two series, 
 
 differing in having their planes inclined at different angles to 
 
 16. 
 
 
 
 
 
 < 
 
 the basal plane. In figs. 5 and 7 there is one of these pyra- 
 mids terminating the prism, and in figs. 6 and 8 the planes 
 of two. In figs. 1 to 3 there are planes of the same octahe- 
 dron, but combined with the basal plane O ; and in fig. 4 there 
 are planes of two, with O. In fig. 9 there are planes of the 
 same octahedron, with planes of a square prism (2-t), and of an 
 eight-sided prism (i-2). In fig. 18 there is the prism 2-2 com- 
 bined with two octahedrons, and the basal plane O; and in 
 19 the planes of one octahedron with the prism J. 
 
 Fig. 20 represents an eight-sided double pyramid, made of 
 
 eh Be 22, 
 
 yy 
 \ J Titi) T 
 equal planes, equally inclined to the base; and fig. 21, the same 
 planes on the square prism i-t. The small planes, in pairs, on 
 fig. 8, are of this kind. In fig. 22 the small planes 3-3 of 
 fig. 8 occur alone, without planes of the four-sided pyramids, 
 and therefore make the eight-sided pyramid, 3-3. 
 
 This solid of sixteen planes has the largest number of similar 
 planes possible in the dimetric system, while the largest number 
 
 in the isometric system (occurring in the hexoctahedron) 1s 
 forty-eight. 
 
 
 
DIMETRIC, OR TETRAGONAL SYSTEM. 33 
 
 2. Positions of the Planes with reference to the Axes.—Let- 
 tering of planes. In the prism fig. 10, the lateral planes are parallel to 
 the vertical axis and to one lateral axis, and meet the other lateral axis 
 at its extremity. The expression for it is hence (¢ standing for the 
 vertical axis and a, } for the lateral) ze : 7b : 1a, 7, as before, standing 
 for infinity and indicating parallelism. For the prism of fig. 12, the 
 prismatic planes meet the two lateral axes at their extremities, and 
 are parallel to the vertical, and . 
 hence the expression for them is 23. 
 ic: 16: 1a. Inthe annexed figure -a 
 the two bisecting lines, a —@ and 
 b —0d, represent the lateral axes ; 
 the line s ¢ stands for a section of 
 a lateral plane of the first of these 
 prisms, it being parallel to one 
 lateral axis and meeting the other 
 at its extremity, and ad for that 
 of the other, it meeting the two 
 at their extremities. 
 
 In the eight-sided prisms (figs. 14, 15), each of the lateral planes is 
 parallel to the vertical axis, meets one of the lateral axes at its extrem- 
 ity, and would meet the other axis if it were prolonged to two or three 
 or more times its length. The line ag, in fig. 23, has the position of one 
 of the eight planes; it meets the axis 0 at 0, or twice its length from 
 the centre; and hence the expression for it would be ie : 26 : 1a, or, 
 since b = a, t¢ : 2: 1, which is a general expression for each of the eight 
 planes. Again, ap has the position of one of the eight planes of an- 
 other such prism; and since Op is three times the length of 0b, the ex- 
 pression for the plane would be w : 3: 1. So there may be other eight- 
 sided prisms; and, putting » for any possible ratio, the expression 
 ic: n: 1 isa general one for all eight-sided prisms in the dimetric sys- 
 tem. 
 
 A plane of the octahedron of fig. 16 meets one lateral axis at its 
 extremity, and is parallel to the other, and it meets the vertical axis ¢ 
 at its extremity ; its expression is consequently (dropping the letters @ 
 and b, because these axes are equal) l¢:7: 1. Other octahedrons in 
 the same vertical series may have the vertical axis longer or shorter 
 than axis ¢; that is, there may be the planes eae Ge ego ee ee 
 4¢:¢:1, and soon; or4$c:%¢:1,4¢:7¢:1, and so on; or, using m for 
 any coefficient of c, the expression becomes general, me:%:1. When 
 m = 0 the vertical axis is zero, and the plane is the basal plane O of 
 the prism ; and when m = infinity, the plane is te: 4:1, or the vertical 
 plane of the prism in the same series, 7-2, fig. 10. 
 
 The planes of the octahedron of fig. 17 meet two lateral axes at their 
 extremities, and the vertical at its extremity, and the expression for the 
 plane is hence 1¢:1:1. Other octahedrons in this series will have the 
 general expression mc:1:1, in which m may have any value, not a 
 decimal, greater or less than unity, as in the preceding case. When in 
 this series m = infinity, the plane is that of the prism ic : 1:1, or that 
 of fig, 12. } 
 
 In the case of the double eight-sided pyramid (figs. 20, 21, 22), 
 the planes meet the two lateral axes at unequal distances from the 
 centre; and also meet the vertical axis. The expression may be 
 
 3 
 
 
 
34 CRYSTALLOGRAPHY. 
 
 9¢:2:1,4¢:2:1, 5¢:3:1, and so on; or, giving it a general form, 
 me:n:1. 
 
 In the lettering of the planes on figures of dimetric crystals, the first 
 number (as in the isometric and all the other systems) is the coefficient 
 of the vertical axis, and the other is the ratio of the other two, and 
 when this ratio is a unit it is omitted. 
 
 The expressions and the lettering for the planes are then as follows: 
 
 Expressions, Lettering. 
 For square prisms 1. wre: tt 
 Nee OE ee a Rees 2° 42154 t or I. 
 For eight-sided prisms......... dou 1-0 
 1 eet a: m-t 
 For octahedrons;,......+.+% 13 me Bs} m 
 For double eight-sided pyramids, mc:n:1 m-n 
 
 The symbols are written without a hyphen on the figures of crystals. 
 On figure 14, the plane 7-7 is that particular ¢-n in which n = ~, or a-2. 
 In fig. 21 the planes of the double eight-sided pyramid, m-n, have 
 m = 1 and n = 2 (the expression being 1 : 2 : 1), and hence itis lettered 
 1-2. In fig. 8 and in fig. 22 it is the one in which m=3 andn = 3 
 (the expression being 3 : 8: 1), and hence the lettering 3-3. 
 
 The length of the vertical axis c may be calculated as follows, pro- 
 vided the crystal affords the required angles: 
 
 Suppose, in the form fig. 18, the inclination of O on plane 1-7 to have 
 been found to be 130°, or of 7-2 on the same plane, 140° (one follows 
 from the other, since the sum of the two, as has been explained, is 
 necessarily 270°). Subtracting 90°, we have 40° for the inclination of 
 the plane on the vertical axis ¢, or 50° for the same on the lateral axis 
 a, or the basal section. In the right-angled triangle, OBC, the angle 
 
 OBC equals 40°. If OC be taken as a = 1, then BC will 
 24. be the length of the vertical axis c; and its value may be 
 y obtained by the equation cot 40° = BC, or tan 50° = BC. 
 On fig. 18 there is a second octahedral plane, lettered 
 }-i, and it might be asked, Why take one plane rather 
 than the other for this calculation? The determination 
 on this point is more or less arbitrary. It is usual to 
 B assume that plane as the unit plane in one or the other 
 series of octahedrons (fig. 16 or fig. 17) which is of most 
 common occurrence, or that which will give the simplest 
 symbols to the crystalline forms of a species; or that 
 which will make the vertical axis nearest to unity; or 
 
 0 © that which corresponds to a cleavage direction. 
 
 The value of the vertical axis having been thus deter- 
 mined from 1-7, the same may be determined in like manner for 3-2 in 
 the same figure (fig. 18). The result would be a value just half that of 
 BC. Or if there were a plane 2-7, the value obtained would be twice 
 BC, or BD in fig. 24; the angle ODC + 90° would equal the inclina- 
 tion of O on 2-¢. So for other planes in the same vertical zone, as 3-1, 
 4-7, or any plane m-?. 
 
 If there were present several planes of the series m-?, and their incli- 
 
DIMETRIC, OR TETRAGONAL SYSTEM. 35 
 
 rations to the basal plane O were known, then, after subtracting from 
 the values 90°, the cotangents of the angles obtained, or the tangents 
 of their complements, will equal m in each case ; that is, the tangents 
 (or cotangents) will vary directly with the value of m. The logarithm 
 of the tangent for the plane 1-7, added to the logarithm of 2, will 
 equal the logarithm of the tangent for the plane 2-2, and so on. 
 
 The law of the tangents for this vertical zone m-? holds for the planes 
 of all possible vertical zones in the dimetric system. Further, if the 
 square prism were laid on its side so that one of the lateral planes be- 
 came the base, and if zones of planes are present on it that are vertical 
 with reference to this assumed base, the law of the tangents still holds, 
 with only this difference to be noted, that then one of the lateral axes 
 is the vertical. It holds also for the ¢rimetric system, no matter which 
 of the diametral planes is taken for the base, since all the axial inter- 
 sections are rectangular. It holds for the monoclinic system for the 
 zone of planes that lies between the axes c and } and that between the 
 axes a and 0, since these axes meet at right angles, but not for that 
 between ¢ and a, the angle of intersection here being oblique. It holds 
 for all vertical zones in the hezagonal system, since the basal plane in 
 this system is at right angles to the vertical axis. But it is of no use 
 in the triclinic system, in which all the axial intersections are oblique. 
 
 The value of the vertical axis c may be calculated also from the incli- 
 nation of O on 1, or of Jon 1. See fig. 2, and compare it with fig. Lis 
 If the angle J on 1 equals 140°, then, after subtracting 90°, we have 50° 
 for the basal angle in the triangle OOB, fig. 24; or for half the inter- 
 facial angle over a basal edge—edge Z—in fig. 17. The value of ¢ 
 may then be calculated by means of the formula 
 
 c= tan+ Zvi, 
 
 by substituting 50° for 7 and working the equation. 
 For any octahedron in the series m, the formula is 
 
 me =tan4Z v4 
 
 Z being the angle over the basal edge of that octahedron. If m= 2, 
 then c = $(tan$Zv4). Further, m = (tan 47 7%) + ©. 
 
 The interfacial angle over the terminal edge of any octahedron m 
 may be obtained, if the value of ¢ is known, by the formulas 
 
 mc = cote cos e = cot 4X 
 
 X being the desired angle (fig. 17). The same for any octahedron m-3 
 may be calculated from the formulas 
 
 me = cote cose =cos4Y 72 
 
 Y being the desired angle (fig. 16). 
 For other methods of calculation reference may be made to the ‘‘ Text 
 Book of Mineralogy,” or to some other work treating of mathematical 
 
 crystallography. 
 
 3. Hemihedral Forms.—Among the few hemihedral forms 
 under the dimetric system there is a tetrahedron, called a spher- 
 
36 CRYSTALLOGRAPHY. 
 
 oid (figs. 25 or 26), and also forms in which only half of the 
 sixteen planes of the double eight-sided pyramid, or half the 
 eight planes of an eight-sided prism—those alternate in position 
 
 wAWG 
 A 
 
 —are present (figs. 27, 28). In fig. 27 the absent planes are 
 those of half the pairs of planes; and in fig. 28 they include 
 one of each of the pairs, as will be seen on comparing these 
 figures with fig. 21. 
 
 4, Cleavage.—In this system cleavage may occur parallel to the 
 sides of either of the square prisms; parallel to the basal plane ; 
 parallel to the faces of a square octahedron ; or in two of these 
 directions at the same time. Cleavage parallel to the base and 
 that parallel to a prism are never equal, so that such prisms 
 need not be confounded with distorted cubes. 
 
 5, Irregularities in Crystals—The square prisms are very 
 often rectangular instead of square, and so with the octahedrons. 
 But, as elsewhere among crystals, the angles remain constant. 
 When forms are thus distorted, the four prismatic planes will have 
 like lustre and surface markings, and thus show that the faces 
 are normally equal and the lateral axes therefore equal. If 
 the plane truncating the edge of a prism makes an angle of 
 precisely 135° with the faces of the prism, this is proof that « 
 the prism is square, or that the lateral axes are equal, since the 
 angle between a diagonal of a square and one of its sides is 45°, 
 and 135° is the supplement of 45°. 
 
 6. Distinctions, —The dimetric prisms have the base different 
 in lustre from the sides, and planes on the basal edges different 
 in angle from those on the lateral, and thus they differ from 
 isometric forms. ‘The lateral edges may be truncated, and the 
 new plane will have an angle of 135° with those of the prism, 
 in which they differ from trimetric forms, while like isometric. 
 The extremities of the prism, if it have any planes besides the 
 basal, will have them in fours or eights, each of the four, or 
 of the eight, inclined to the base, at the same angle. When 
 there is any cleavage parallel to the vertical axis, it is alike 
 
TRIMETRIC, OR ORTHORHOMBIC SYSTEM. oF 
 
 +1 two directions at right angles with one another. The 
 lateral planes of either square prism are alike in lustre and 
 markings. 
 
 III. TRIMETRIC, on ORTHORHOMBIC SYSTEM. 
 
 1. Descriptions of Forms.—The crystals under the trimetric 
 system vary from rectangular to rhombic prisms and rhombic 
 octahedrons, and include various combinations of such forms. 
 Figs. 1 to 7 are a few of those of the species barite, and figs. § 
 to 10 of crystals of sulphur. 
 
 
 
 BARITE. SULPHUR. 
 
 Fig. 11 represents a rectangular prism (diametral prism), 
 and fig. 12 a rhombic prism, each with the axes. The axes 
 connect the centres of the opposite planes in the former ; but 
 in the latter the lateral axes connect the centres of the oppo- 
 site edges. Of the two lateral axes the longer is called the 
 macrodiagonal, and the shorter the brachydiagonal. The verti- 
 cal section containing the former is the macrodiagonal section 
 and that containing the latter, the brachydiagonal section. 
 
 In the rectangular prism, fig. 11, only opposite planes are alike, 
 because the three axes are unequal. Of these planes, that oppo- 
 site to the larger lateral axis is called the macropinacoid, and 
 that opposite the shorter the brachypinacoid (from the Greek for 
 
 long and short, and a word signifying board or table). Hach 
 
o8 CRYSTALLOGRAPHY. 
 
 pair—that is, one of these planes and its. opposite—is called a 
 hemiprism. | 
 
 In the rhombic prism, fig. 12, the four lateral planes are 
 similar planes. But of the four lateral edges of the prism two 
 
 
 
 are obtuse and two acute. Fig. 13 represents a combination of 
 the rectangular and rhombic prisms, and illustrates the rela- 
 tions of their planes. Other rhombic prisms parallel to the 
 vertical axis occur, differing in interfacial angles, that is, in the 
 ratio of the lateral axes. 
 
 Besides vertical rhombic prisms, there are also horizontal 
 prisms parallel to each lateral axis,aand 6. In fig. 2 the narrow 
 planes in front (lettered 42) are planes of a rhombic prism parallel 
 to the longer of the lateral axes, and those to the right (1%) are 
 planes of another parallel to the shorter lateral axis. In fig. 6 
 the planes are those of these two horizontal prisms. Such 
 prisms are called also domes, because they have the form of the 
 roof of a house (domus in Latin meaning house). In fig. 3 
 these same two domes occur, and also the planes (lettered J) of 
 a vertical rhombic prism. Of these domes there may be many 
 both in the macrodiagonal and the brachydiagonal series, differing 
 in angle (or in ratio of the two intersected axes). Those par- 
 allel to the longer lateral axis, or the macrodiagonal, are called 
 macrodomes ; and those parallel to the shorter, or brachydiag- 
 onal, are called brachydomes. 
 
 A rhombic octahedron, lettered 1, is shown in fig. 8; a com- 
 bination of two, lettered 1 and 4, in tig. 9; and a combination 
 of four, lettered 1, 4, 4, 4, in fig. 10. This last figure contains 
 also the planes J, or those of a vertical rhombic prism; the 
 planes 1-2, or those of a dome parallel to the longer lateral axis 5 
 the planes 1-é, or those of a dome parallel to the shorter lateral 
 axis; the plane QO, or the basal plane; the plane 7-7, or the 
 brachypinacoid ; and also a rhombic octahedron lettered 1-3. 
 
 2, Positions of Planes, Lettering of Crystals,—The notation 
 is, ina general way, like that of the dimetric system, but with differ- 
 ences made necessary by the inequality of the lateral axes. The letters 
 
TRIMETRIC, OR ORTHORHOMBIC SYSTEM. 39 
 
 v 
 
 for the three are written ¢: 6: a; 6 being the longer lateral and a the 
 shorter lateral. In place of the square prism of the dimetric system, 
 i-t, there are the hemiprisms 2-2 and i-z, or the macropinacoid and brachy- 
 pinacoid, having the expressions ?¢ : ib: 1d and ic: 46:74. The form I 
 is the rhombic prism, having the expression é¢ : 10: 1d, corresponding 
 to the square prism J in the dimetric system. The planes 2-7 or 2-7 
 are other rhombic vertical prisms, the former corresponding to 
 tc: nb: 1d, the other to tc: 16: nd. If n=2, the plane is lettered 
 either ¢-2 or 7-3. The plane 1-3 has the expression Ice: 16:3¢. m-% 
 and m-ii comprise all possible rhombic prisms and octahedrons, and 
 correspond to the expressions mc : 2b : 1d and mc:16: nd. When m= 
 infinity they become @-” and 7-7, or expressions for vertical rhombic 
 prisms; when n = infinity they become m-t and m-t, or expressions for 
 macrodomes and brachydomes. 
 
 The question which of the three axes should be taken as the vertical 
 axis is often decided by reference simply to mathematical convenience. 
 Sometimes the crystals are prominently prismatic only in one direction, 
 as in topaz, and then the axis in this direction is made the vertical. In 
 many cases a cleavage rhombic prism, when there is ong, is made the 
 vertical, but exceptions to this are numerous. There is also no general 
 rule for deciding which octahedron should be taken for the unit octahe- 
 dron, But however decided, the axial relations for the planes will re- 
 main essentially the same. In fig. 10, had the plane lettered 4 been 
 made the plane 1, then the series, instead of being as it is in the figure, 
 1, +, 4; 4, would have been 2, 1, 3, 2, in which the mutual axial rela- 
 tions are the same. 
 
 The relative values of the axes in the trimetric system may be calcu- 
 lated in the same way as that of the vertical axis in the dimetric sys- 
 tem, explained on page 34. The law of the tangents, as stated on page 
 30, holds for this system. 
 
 3 Hemihedral Forms.—Hemihedral forms are not common 
 in this system. Some of those so considered have been proved 
 to owe their apparent hemihedrism to their being of the mono- 
 clinic system, as in the case of datolite and two species of the 
 chondrodite group. In a few kinds, as, for example, calamine, 
 one extremity of a crystal differs in its planes from the other. 
 Such forms are termed hemimorphic, from the Greek for half 
 and form. They become polar electric when heated, that is, 
 are pyroelectric, showing that this hemimorphism is connected 
 with polarity in the crystal. 
 
 4, Cleavage.—Cleavage may take place in the direction of 
 either of the diametral planes (that is, either face of the rectan- 
 gular prism) ; but it will be different in facility and~in the sur- 
 face afforded for each. In anhydrite, however, the difference is 
 very small. Cleavage may also occur in the direction of the 
 planes of a rhombic prism, either alone or in connection with 
 cleavage in other directions. It also sometimes occurs, as in 
 sulphur, parallel to the faces of a rhombic octahedron. 
 
40 CRYSTALLOGRAPHY. 
 
 5. Irregularities in Crystals—The crystals almost never cor- 
 respond in their diametral dimensions with the calculated axial 
 dimensions. ‘They are always lengthened, widened, shortened, 
 or narrowed abnormally, but without affecting the angles. Ex- 
 amples of diversity in this kind of distortion are given in figs. 
 1 to 7, of barite. 
 
 6. Distinctions.—In the trimetric system the angle 135° does 
 not occur, because the three axes are unequal. ‘There are pyra- 
 mids of four similar planes in the system, but never of eight; 
 and the angles over the terminal edges of the pyramids are 
 never equal as they are in the dimetric system. The rectangu- 
 lar octahedron of the trimetric system is made up of two hori- 
 zontal prisms, as shown in fig. 6, and is therefore not a simple 
 form ; and it differs from the octahedron of the dimetric sys- 
 tem corresponding to it (fig. 16, p. 32) in having the angles 
 over the basal edges of two values. 
 
 IV. MONOCLINIC SYSTEM. 
 
 1. Descriptions of Forms,—In this system the three axes are 
 unequal, as in the trimetric system; but one of the axial inter- 
 sections is oblique, that between the axis a and the vertical axis 
 c. The following examples of its crystalline forms, figs. 1 to 6, 
 show the effect of this obliquity. On account of it the front 
 or back planes above and below the middle in these figures 
 differ, and the anterior and posterior prismatic planes are une- 
 
 qually inclined to a basal plane. 
 
 PYROXENE, FELDSPAR. HORNBLENDE. 
 
 
 
 The axes and their relations are illustrated, in figs. 7 and 8. 
 Fig. 7 represents an oblique rectangular prism, and fig. 8 
 an oblique rhombic. The former is the diametral prism, like 
 the rectangular of the trimetric system. The axes connect 
 the centres of the cpposite faces, and the planes are of three 
 
MONOCLINIC SYSTEM. ~~ aE 
 
 distinct kinds, being parallel to unlike axes and diametral sec- 
 tions. In the latter, as in the trimetric rhombic prism, the 
 lateral axes connect the centres of the opposite sides. More- 
 over, this rhombic prism may be reduced to the rectangular by 
 the removal of its edges by planes parallel to the lateral axes. 
 
 
 
 MONAZITE. MIRABILITE. 
 
 The axis a, or the inclined lateral axis (inclined at an oblique 
 angle to the vertical axis c), is called the clinodiagonal , and the 
 axis b, which is not inclined, the orthodiagonal (from the Greek 
 for right, or rectangular). The vertical section through the 
 former is called the clinodiagonal section ; it is parallel to the 
 plane i2 (fig. 1-6). The vertical section through the latter is 
 
 7. 8. 
 
 the orthodiagonal section ; itis parallel to planes i-t. Owing to 
 the oblique angle between a and ¢, the planes above o@ differ 
 in their relations to the axes from those below, and hence comes 
 the difference in the angle they make with the basal plane. 
 
 The halves of a crystal either side of the clinodiagonal section 
 __the vertical section through a and c-—are alike in all planes 
 and angles. Another important fact is this: that the plane 2, 
 or that parallel to the clinodiagonal section, is at right angles not 
 only to O and %-i, but to all planes in the zone of O and 7; 
 
 
 
 
42 CRYSTALLOGRAPHY. 
 
 that is, in the clinodiagonal zone; and this is a consequence of 
 the right angle which axis 6 makes with both axis ¢ and AXIS a. 
 The plane -2 is called the orthopinacoid, it being parallel to the 
 orthodiagonal; and the plane 7-2, the clinopinacoid, it being 
 parallel to the clinodiagonal. 
 
 Vertical rhombic prisms have the same relations to the lateral 
 axes as in the trimetric system. Domes, or horizontal rhombic 
 prisms, occur in the orthodiagonal zone, because the vertical 
 axis c and the orthodiagonal 6 make right angles with one 
 another. In fig. 6 the planes 1-2, 2-2 belong to two such 
 domes. They are called clinodomes, because parallel to the 
 clinodiagonal. — 
 
 In the clinodiagonal zone, on the contrary, the planes above 
 and below the basal plane differ, as already stated, and hence 
 there can be no orthodomes; they are hemiorthodomes. ‘Thus, 
 in fig. 6, 4-2, 1-¢ are planes of hemiorthodomes above 2-2, and 
 —4i-iisa plane of another of different angle below it. The 
 plane, and its diagonally opposite, make the hemiorthodome. 
 
 The octahedral planes above the plane of the lateral axes also 
 differ from those below. Thus, in figs. 5 and 6, the planes 1, 1 
 are, in their inclinations, different planes from the planes —1, 
 —1;soinall cases. Thus there can be no monoclinic octahedrons 
 —only hemioctahedrons. An oblique octahedron is made up of 
 two sets of planes; that is, planes of two hemioctahedrons. 
 Such an octahedron may be modelled and figured, but it will 
 consist of two sets of planes: one set including the two above 
 the basal section in front and their diagonally opposites behind 
 
 
 
 (fig. 9), and the other set including the two below the basal sec- 
 tion and their diagonally opposites (fig. 10). 
 
 A hemioctahedron, since it consists of only four planes, is 
 really an obliquely placed rhombic prism, and very frequently 
 they are so lengthened as to be actual prisms. 
 
TRICLINIC SYSTEM. 43 
 
 9. Positions of Planes. Lettering of Crystals—On account of 
 the obliquity of the crystals, the planes above and below the basal sec- 
 tion require a distinguishing mark in their lettering, as well as in the 
 mathematical expressions for them. One set is made minus and the 
 other plus. The plus sign is omitted in the lettering. In fig. 7 there 
 are above the basal section (or above 2-2) the planes 1-2, 4-2, 1, 4, but be- 
 low it, —4-¢, —1. The plus planes are those opposite the acute inter- 
 section of the basal and orthodiagonal sections, and the minus those 
 opposite the obtuse. No signs are needed for planes of the clinodiago- 
 nal section, since they are alike both above and below the basal sec- 
 tion. 
 
 The distinction of longer and shorter lateral axis is not available in 
 this system, since either may be the clinodiagonal. The distinction of 
 clinodiagonal and orthodiagonal planes is indicated by a grave accent 
 over the number or letters referring to the clinodiagonal. The lettering 
 for the clinodomes on fig. 6 is 1-2, 2-i—the @ (initial of infinite, with 
 the accent) signifying parallelism to the clinodiagonal. The hemiocta- 
 hedrons, 1, 2, etc., need no such mark, as the expression for them 
 is1c:1b:1d, 2c: 10:12, the planes having a unit ratio for @ and 0. 
 But the plane 2-2, in fig. 5, requires it, its expression being pT Me ss Drea Se 
 the fact that the last 2 refers to the clinodiagonal is indicated by 
 the accent. If it referred to the orthodiagonal, that is, if the expres- 
 sion for the plane were 2c : 20 : 1a, it would be written 2-2 without the 
 accent. 
 
 8. Cleavage. Cleavage may be basal, or parallel to either of 
 the other diametral sections, or parallel to a vertical rhombic 
 prism, or to the planes of a hemioctahedron ; or to the planes of 
 a clinodome, or to that of a hemiorthodome. If occurring in two 
 or more directions in any species it is always different in degree 
 in each different direction, as in all the other systems. 
 
 4, Irregularities,—Crystals of this system may be elongated 
 abnormally in the direction of either axis, and any diagonal. 
 The hemiorthodomes may be in aspect the bases of prisms, and 
 the hemioctahedrons the sides of prisms. Which plane in the 
 zone of hemiorthodomes should be made the base, and which in 
 the series of hemioctahedrons should be assumed as the funda- 
 mental prism determining the direction of the vertical axis, is 
 often decided differently by different crystallographers. Con- 
 venience of mathematical calculation is often the principal point 
 referred to in order to reach a conclusion. 
 
 V. TRICLINIC SYSTEM. 
 
 1. Descriptions of Forms.—In the triclinic system the three 
 axes are unequal and their three intersections are oblique, and 
 consequently there are never more than two planes of a kind ; 
 
44 ORYSTALLOGRAPHY. 
 
 that is, planes having the same inclinations to either diametral 
 section, The following are examples : 
 
 
 
 AXINITE. ANORTHITE, AMBLYGONITE, 
 
 The difference in angle from monoclinic forms is often very 
 small, ‘This is true in the Feldspar family. Fig. 2, of the 
 feldspar called anorthite, 1s very similar in general form to 
 fig. 4, of orthoclase, which is monoclinic. This is still more 
 strikingly seen on comparing fig. 4 with fig. 5, representing 
 a crystal of oligoclase, another one of the triclinic feldspars. The 
 
 
 
 ORTHOCLASE. OLIGOCLASE. 
 
 planes on the two are the same with one exception; but there 
 is this difference, that in orthoclase, as in all monoclinic erys- 
 tals, the angle between the planes O and 2-? (the two directions 
 
HEXAGONAL SECTION OF HEXAGONAL SYSTEM. 45 
 
 of cleavage) is 90°; and in oligoclase and the other triclinic 
 feldspars it is 3° to 5° from 90°, being in oligoclase 93° 50’, and 
 sn anorthite 94° 10’. This difference in angle involves oblique 
 intersections between the axes 0 and ¢, and c and a, which are 
 rectangular in monoclinic forms. There is a similarly close re- 
 lation between the triclinic form of rhodonite and that of pyrox- 
 ene, and a resemblance also in composition. 
 
 The diametral prism in this system is similar to fig. 7 on 
 page 41, under the monoclinic system, but differs in having the 
 planes all rhomboidal instead of part rectangular. The form 
 corresponding to the oblique rhombic prism of the monoclinic 
 system (fig. 8, p. 41) also has rhomboidal instead of rhombic 
 planes; moreover, the two prismatic planes have unequal in- 
 ‘clinations to the vertical diametral section, and are therefore 
 dissimilar planes. The prism, consequently, is made of two 
 hemiprisms, and the basal plane is another, making in all three 
 hemiprisms. 
 
 2, Cleavage.—Cleavage takes place independently in differ- 
 ent diametral or diagonal directions. In the triclinic feldspars 
 it conforms to the directions in orthoclase, with only the excep- 
 tion arising from the obliquity above explained. 
 
 VI. HEXAGONAL SYSTEM. 
 
 This system is distinguished from the others by the charac- 
 ter of its symmetry—the number of planes of a kind around 
 the vertical axis being a multiple of 3. The number of lateral 
 axes is hence 3. It is related to the dimetric system in having 
 the lateral axes at right angles to the vertical and equal, and is 
 hence like it also in the optical characters of its crystals. Its 
 hexagonal prismatic form approaches trimetric crystals in the 
 obtuse angle (120°) of the prism, some trimetric crystals having 
 an angle of nearly 120°. 
 
 Under this system there are two sections : 
 
 1. The HexAGonaL SECTION, in which the number of planes 
 of a kind around each vertical axis above or below the basal 
 section is 6 or 12. 
 
 9. The RHOMBOHEDRAL SECTION, in which the number of 
 planes of a kind around each half of the vertical axis, above or 
 below the basal section, is 3 or 6; and, in addition, the planes 
 above are alternate in position with those below. The forms 
 are mathematically hemihedral to the hexagonal, but not so 
 in their real nature. 
 
46 CRYSTALLOGRAPHY. 
 
 I. HEXAGONAL SECTION, 
 
 1, Description of Forms.—Figs. 1 to 3 represent some of the 
 forms under this section. Figs. 2 and 3 show only one ex- 
 
 
 
 APATITE. 
 
 
 
 tremity; and such crystals are seldom perfect at both. All 
 exhibit well the symmetry by sixes which characterizes this 
 section of the hexagonal system. 
 
 
 
 Prisms. Under this system there are two hexagonal prisms , 
 and a number of occurring twelve-sided prisms. Fig. 4 repre- 
 sents one of the hexagonal prisms, with its axes—the three 
 lateral connecting the centres of the opposite edges. The 
 lateral angles of the prism are 120°. If the lateral edges of 
 this prism are truncated, as in the figure of apatite (fig. 3), the 
 truncating planes, 2-2, are the lateral faces of another similar 
 hexagonal prism, in which, as the relations of the two show, the 
 
HEXAGONAL SECTION OF HEXAGONAL SYSTEM. AT 
 
 lateral axes connect the centres of the opposite lateral faces. 
 This prism is represented in fig. 5. 
 
 The lateral edges of the hexagonal prisms occur sometimes 
 with two similar planes on each edge, and these planes, when 
 extended to the obliteration of the hexagonal prism, make 
 a twelve-sided prism. These two 
 planes are seen in fig. 8, along 
 with the planes Z of the hexago- 
 nal prism, and 1 of a double six- 
 sided pyramid, besides the basal 
 plane O. 
 
 Double pyramids. The double 
 pyramids are of three kinds: (1) 
 A series of six-sided, whose planes belong to the same verti- 
 cal zone with the planes Z. The planes of two such pyramids 
 (lettered 1, 2) are shown in figs. 1 and 2, three of them in fig. 
 3 (lettered 3, 1, 2), and one in fig. 7, and one such double 
 pyramid, without combination with other planes, in fig. 6. 
 (2) A series of six-sided double pyramids, whose planes are in 
 the same vertical zone with i-2, examples of which occur on fig. 
 _2 (plane 2-2)—on fig. 3 (planes 1-2, 2-2, 4-2). The form of this 
 double pyramid is like that represented in fig. 6, but the lateral 
 axes connect the centres of the basal edges. The double six- 
 sided pyramid is sometimes called a quartzoid, because it occurs 
 in quartz. (3) Twelve-sided double pyramids. ‘Two planes of 
 such a pyramid are shown ona hexagonal prism in fig. 9, also in 
 
 
 
 
 
 fig. 2 (the planes 3-3), and the simple form consisting of such 
 planes in fig. ]0—a form called a berylloid, as the planes are 
 common in beryl. In fig. 11 the planes 1 belong to a double 
 six-sided pyramid; and those next below (of which three are 
 lettered W) to a double twelve-sided pyramid. 
 
48 CRYSTALLOGRAPHY. 
 
 9. Lettering of Crystals—The prism of fig. 5 is lettered 1-2, be- 
 cause it is parallel to the vertical axis, and has the ratio of 1: 2 between 
 two lateral axes. This is shown in the annexed figure, which repre- 
 sents the hexagonal outline of the prism 
 4-2 circumscribing that of the prism J. 
 The plane 7-2 is produced to meet axis 
 a, which it does when @ is extended to 
 twice its length ; whence the ratio for 
 the axes a, a’, is 1: 2. 
 
 The numbers 1, 2, on the double hexa- 
 gonal pyramids in fig. 1 indicate the 
 relative lengths of the vertical axis 
 
 ne, of the two pyramids, they having the 
 A i2 G BR same 1:1 ratio of the lateral axes; and 
 so in figs. 2, 8, and others. 
 
 The lettering on the pyramids of the other series in fig. 3, 1-2, 2-2, 
 4-2, indicates, by the second figure, that the planes are in the same 
 vertical zone with the prismatic plane 7-2, and by the first figure the rel- 
 ative lengths of the vertical axes. 
 
 In the twelve-sided prisms such ratios as 7-3, 7-3, ¢-& occur. The 
 fraction in any case expresses the ratio of the lateral axes for the par- 
 ticular planes. The double twelve-sided pyramids have the ratios 3-3 
 (fig. 2), 4-4, and others. Both im these forms and the twelve-sided 
 prisms, the second figure in the lettering, expressing the ratio of the 
 lateral axes, has necessarily a value between 1 and 2, 
 
 
 
 8. Hemihedral Forms.—Fig. 13 represents a crystal of apa- 
 tive in which there are two sets of planes, 0 (=3-3) and o’ (=4-4) 
 which are hemihedral, only half of 
 the full number of each o existing 
 instead of all. This kind of hemi- 
 hedrism consists in the suppression 
 of an alternate half of the planes 
 in each pyramid of the double 
 twelve-sided pyramid (fig. 10), and 
 in the suppressed planes of the 
 upper pyramid being here directly 
 over those suppressed in the lower 
 pyramid. If the student will shade 
 over half the planes alternately of 
 the two pyramids, putting the APATITE. 
 shaded planes above directly over 
 those below, he will understand the nature of the hemihedrism. 
 In some hemihedral forms the suppressed planes of the upper 
 pyramid alternate with those of the lower; but this kind 
 occurs only in the rhombohedral section of the hexagonal 
 system. 
 
 4, Cleavage,—Cleavage is usually basal, or parallel to a six- 
 
 
 
RHOMBOHEDRAL SECTION OF HEXAGONAL SYSTEM. 49 
 
 sided pyramid. Sometimes there are traces of cleavage parallel | 
 to the faces of a six-sided pyramid. 
 
 5. Irregularities of Crystals,— 
 Distortions sometimes disguise 14, 
 greatly the real forms of hexagonal 
 crystals by enlarging some planes 
 at the expense of others. This is © 
 illustrated in fig. 14, representing 
 the actual form presented by a 
 crystal having the planes shown 
 in fig. 13. Whenever in a prism 
 the prismatic angle is exactly 120° 
 or 150°, the form is almost always 
 of the hexagonal system. 
 
 
 
 2, RHOMBOHEDRAL SECTION. 
 
 1. Descriptions of Forms.—The following figures, 1 to 17, 
 represent rhombohedral crystals, and all are of one mineral, cal- 
 cite. They show that the planes of either end of the crystal 
 are in threes, or multiples of threes, and that those above are 
 alternate in position with those below. There is one exception 
 
 
 
 FIGURES OF CRYSTALS'\OF CALCITE. 
 
 to this remark, that of the horizontal or basal plane O, in figs. 
 8, 11, 13. Thesimple rhombohedral forms include: 
 
 1. Rhombohedrons, figs. 1 to 6. These forms are included 
 under six equal planes, like the cube, but these planes are 
 
50 CRYSTALLOGRAPHY. 
 
 rhombic ; and instead of having twelve rectangular edges, they 
 have six obtuse edges and six acute. 
 
 2. Scalenohedrons, fig. 7. Scalenohedrons are really double 
 six-sided pyramids; but the six equal faces of each extremity 
 
 15. 16. 
 
 |W 
 
 FIGURES OF CRYSTALS OF CALCITE. 
 
 
 
 of the crystals are scalene triangles, and are arranged in three 
 pairs; moreover the pairs above alternate with the pairs below ; 
 the edges in which the pairs above and below meet—that is the 
 basal edges—make a zig-zag around the crystal. 
 
 3. Hexagonal prisms, J, fig. 8. These are regular hexagonal 
 prisms, having angles between their faces of 120°. 
 
 A rhombohedron has two of its solid angles made up of three . 
 equal plane angles. When in position the apex of one of these 
 solid angles is directly over that of the other, as in figs. 1 to 6, 
 and also in fig. 18, and the line connecting the apices of these 
 angles (fig. 18) is called the vertical axis. In this position 
 
 ™ 
 
 18. 
 
 
 
 the rhombohedron has six terminal edges, three above and 
 three below, and six lateral edges. As these lateral edges 
 are symmetrically situated around the centre of the crystal, the 
 three lines connecting the centres of opposite basal edges will 
 cross at angles of 60°. These lines are the lateral axes of the 
 
RHOMBOHEDRAL SECTION OF HEXAGONAL SYSTEM. 51 
 
 rhombohedron, and they are at right angles to the vertical axis. 
 It is stated on page 45 that rhombohedral forms are, from a 
 mathematical point of view, hemihedral under the hexagonal 
 system. ‘The rhombohedron, which may be considered a double 
 three-sided pyramid, is hemihedral to the double six-sided pyra- 
 mid. Fig. 19, representing the latter form, has its alternate 
 faces shaded ; suppressing the faces shaded the form would be 
 that of fig. 18; and suppressing, instead of these, the faces not 
 shaded, the form would be that of another rhombohedron, dif- 
 fering only in position. The two are distinguished as plus and 
 minus rhombohedrons. They are combined in figs. 20, 21, 
 forms of quartz. Rhombohedrons vary greatly in the length of 
 the vertical axis with reference to the lateral. Figs. 1, 2, 3, and 
 18 represent crystals with the vertical axis short, and figs. 4, 5, 
 6 others with a long vertical axis. In the former the terminal 
 edges are obtuse and the lateral acute, and the latter have the 
 terminal edges acute and the lateral obtuse; the former are 
 called obtuse rhombohedrons, and the latter acute. 
 
 The cube placed on one solid angle, with the diagonal between 
 it and the opposite solid angle vertical, is, in fact, a rhombohe- 
 dron intermediate between obtuse and acute rhombohedrons— 
 the edges that are the terminal in this position, and those that 
 are the lateral, being alike rectangular edges. Fig. 3 has nearly 
 the form of a cube in this position. 
 
 The relation of one series of scalenohedrons to the rhombo- 
 hedron is illustrated in fig. 22. This figure 
 represents a rhombohedron with the lateral 22. 
 edges bevelled. These bevelling: planes are A 
 those of a scalenohedron, and the outer lines ae 
 of the same figure show the form of that 
 scalenohedron which is obtained when the 
 bevelment is continued to the obliteration 
 of the rhombohedral planes. Fig. 14 repre- 
 sents this scalenohedron with the rhombohe- 
 dral planes much reduced in size. Other 
 scalenohedrons result when the terminal 
 edges are beveiled, and still others from 
 pairs of planes on the angles of a rhombohe- 
 dron. sy 
 
 The scalenohedron is hemihedral to the h 
 twelve-sided double pyramid (fig. 23). ‘ 
 
 In the hexagonal system the three verti- Ts 
 cal axial planes divide the space about the ¥ 
 vertical axis into six sectors (fig. 12, p. 48). 
 
 
 
 
 
52 CRYSTALLOGRAPHY. 
 
 The twelve-sided double pyramid has in each pyramid a pair 
 of faces for each sector; that is, six pairs foreach pyramid. If 
 now the three alternate of these pairs, and those in the upper 
 pyramid alternate with those of the lower (the shaded in fig. 23), 
 were enlarged to the obliteration of the rest of the planes, the 
 resulting form would be a scalenohedron—a 
 solid with three pairs of planes to each pyra- 
 mid instead of six.. Such is the mathematical 
 relation of the scalenohedron to the twelve- 
 sided double pyramid. If the faces enlarged 
 were those not shaded in fig. 23, another 
 scalenohedron would be obtained which would 
 be the minus scalenohedron, if the other were 
 designated the plus. 
 
 Fig. 8 shows the relations of a rhombohe- 
 dron to a hexagonal prism. The planes /t 
 replace three of the terminal edges at each base of the prism, 
 and those above alternate with those below. The extension 
 of the planes R to the obliteration of those of the prismatic 
 planes, J, and that of the basal plane O, would produce the 
 rhombohedron of fig. 1. Figs. 9 and 10 represent the same 
 prism, but with terminations made by the rhombohedron of fig. 2. 
 
 By comparing the above figures, and noting that the planes 
 of similar forms are lettered alike, the combinations in the 
 figures will be understood. Fig. 16 is a combination of the 
 planes of the fundamental rhombohedron R, with those of an- 
 other rhombohedron 4, and of two scalenohedrons 1* and I’. 
 Fig. 17 contains the planes of the rhombohedron —4, with those 
 of the scalenohedron 1*, and those of the prism 7. These figures, 
 and figs. 14, 22, have the fundamental rhombohedron revolved 
 60° from the position in fig. 1, so that two planes /¢ are in view 
 above instead of the one in that figure. 
 
 29. 
 
 
 
 9. Lettering of Figures.—Figs. 1 to 6, representing rhombohe- 
 drons of the species calcite, are lettered with numerals, excepting fig. Li 
 In fig. 1 the letter R stands for the numeral 1, and the numerals on the 
 others represent the relative lengths of their vertical axes, the lateral 
 being equal. In fig. 4 the vertical axis is twice that in fig. 1; in fig. 6 
 thirteen times ; and in fig. 15 the planes lettered 16 are those of a rhom- 
 bohedron whose vertical axis is sixteen times that of fig. 1. The rhom- 
 bohedrons of figs. 1, 5, 6, and 15 are plus rhombohedrons; that is, they 
 are in the same vertical series; while 2 and 3 are minus rhombohe- 
 drons, as explained above. The rhombohedron, when its vertical axis 
 is reduced in length to zero, becomes the singie basal plane lettered O 
 in the series. If, on the contrary, the vertical axis of the rhombohe- 
 dron is lengthened to infinity, the faces of the rhombohedron become 
 
RHOMBOUEDRAL SECTION OF HEXAGONAL SysTEM. 53 
 
 those of a six-sided prism. This last will be seen from the relations 
 of the planes & to J on fig. 8, and from the approximation to a prismatic 
 form in the planes 16 of fig. 15. Foran explanation of the lettering 
 of other planes on rhombohedral crystals, reference must be made to 
 the ‘‘ Text-Book of Mineralogy.” 
 
 8. Hemihedrism. Tetartohedrism,— Hemihedrism occurs 
 among rhombohedral forms, similar to that in fig. 13, page 48, 
 except that the suppressed planes of one pyramid are alternate 
 with those of the other. One of these is 
 represented in fig. 24. The planes 6-§ are 
 six In number at each extremity, and are so 
 situated that they give a spiral aspect to the 
 crystal. If these planes were only three in 
 number at each extremity, the alternate 
 three of the six, the form would be tetarto- 
 hedral to the double six-sided pyramid 5 
 that is, there would be one-fourth the num- 
 ber of planes that exist in the double twelve- 
 sided pyramid, or 6 planes instead of 24. 
 Such cases of hemihedrism and tetartohe- 
 drism are common in crystals of quartz, and 
 when existing, the crystals are said to be 
 plagihedral, from the Greek for oblique and 
 face. Insome crystals the spiral turns to the 
 right and in others to the left, and the two kinds are distin- 
 guished as right-handed and left-handed. There are also tetar- 
 tohedral forms in which one whole pyramid of a scalenohedron, 
 or of a rhombohedron, is wanting. For example, in crystals of 
 tourmaline rhombohedral planes, and sometimes scalenohedral, 
 may occur at one extremity of the prism and be absent from 
 the other. This dissimilarity in the two extremities of a crys- 
 tal of tourmaline is connected with pyro-electric polarity in the 
 mineral. Three-sided prisms, hemihedral to the hexagonal prism, 
 are common in some rhombohedral species, as tourmaline. 
 
 4. Cleavage.—Cleavage usually takes place parallel to the | 
 faces of a rhombohedron, as in calcite, corundum. Not unfre- 
 ~ quently the rhombohedral cleavage is wanting, 
 
 and there is highly perfect cleavage parallel to 
 the basal plane, as in graphite, brucite. 
 
 5. Irregularities of Crystals Distortions oc- 
 cur of the same nature with those under the 
 other systems. Some examples are given under 
 quartz. Some rhombohedral species, as dolomite, 
 
 have the opposite faces convex or concave, as in fig. 20. 
 
 
 
 
 
54 CRYSTALLOGRAPHY. 
 
 Occasional curved crystals occur, as in fig. 26, representing 
 crystals of quartz, and fig. 2/ of a crystal of chlorite. The 
 
 
 
 QUARTZ. CHLORITE. 
 
 feathery crystallizations on windows, called frost, are examples 
 of curved forms under this system. 
 
 VII. DISTINGUISHING CHARACTERS OF THE SEVERAL 
 SYSTEMS OF CRYSTALLIZATION. 
 
 1. Isometric System.—(1) There may be symmetrical groups 
 of 4 and 8 similar planes about the extremities of each cubic 
 axis; and of 3 or 6 similar planes about the extremities of each 
 octahedral axis. (2) Simple holohedral forms may consist of 
 6 (cube), 8 (octahedron), 12 (dodecahedron), 24 (trapezohedron, 
 trigonal trisoctahedron, and tetrahexahedron), and 48 (hexoc- 
 tahedron) planes. 
 
 2. Dimerric System.—(1) Symmetrical groups of 4 and 8 
 similar planes occur about the extremities of the vertical 
 axis only. (2) Prisms occur parallel only to the vertical axis; 
 and these prisms are either square or eight-sided. (3) The 
 simple holohedral forms may consist of 2 planes (the bases), of 
 4 planes (square prisms), of 8 planes (eight-sided prisms and 
 square octahedrons), of 16 planes (double eight-sided pyra- 
 mids). 
 
 3. fees System.—(1) Symmetrical groups of 4 similar 
 planes may occur about the extremities of either axis, but 
 those of one axis belong equally to the others. (2) The prisms 
 are rhombic prisms only, and these may occur parallel to either 
 axis, the horizontal as well as the vertical. (3) Simple holo- 
 
TWIN, OR COMPOUND ORYSTALS. 55 
 
 hedral forms may consist of 2 pianes (the bases, and each pair 
 of diametral planes), of 4 planes (rhombic prisms in the three 
 axial directions), and of 8 planes (the rhombic octahedrons). 
 (4) The forms may be divided into equal halves, symmetrical in 
 planes, along each of the diametral sections. 
 
 4. Monoctinic System.—(1) No symmetrical groups of 
 similar planes ever occur around the extremities of either axis. 
 (2) The prisms are rhombic prisms, and these can occur paral- 
 lel only to the vertical axis and the clinodiagonal. (3) The 
 planes occurring in vertical sections above and below the basal 
 section, either in front or behind, are all unlike in inclination 
 to that section, excepting the prismatic planes in the ortho- 
 diagonal zone ; in other words, true prisms occur in no vertical 
 section excepting the orthodiagonal. (4) Simple forms consist of 
 2 planes (the bases, the diametral planes, and hemiorthodomes), 
 of 4 planes (rhombic prisms in two directions and hemioctahe- 
 drons). (4) The forms may be divided into equal and similar 
 halves only along the clinodiagonal section. No interfacial 
 angle of 90° occurs except between the planes of the clinodiag- 
 onal zone and the clinopinacoid. 
 
 5. Tricuinic System. —In triclinic crystals there are no 
 groups of similar planes which include more than 2 planes, and 
 hence the simple forms consist of 2 planes only. The forms 
 are not divisible into halves having symmetrical planes. There 
 are no interfacial angles of 90°. 
 
 6. HexaconaL System.—Symmetrical groups of 3, 6, and 12 
 similar planes may occur about the extremities of the vertical 
 axis. (2) Prisms occur parallel to the vertical axis, and are 
 either six or twelve-sided (3 in a hemihedral form) and equi- 
 lateral. (3) Simple holohedral forms may consist of 2 planes 
 (the basal), of 6 planes (hexagonal prism), of 12 planes (twelve- 
 sided prisms and double six-sided pyramids), of 24 planes 
 (double twelve-sided pyramids). Simple rhombohedral forms 
 may consist of 2 planes (the basal), of 6 planes (rhombohedrons) 4 
 and of 12 planes (scalenohedrons). 
 
 9. TWIN, or COMPOUND CRYSTALS. 
 
 Compound crystals consist of two or more single crystals, 
 united usually parallel to an axial or diagonal section. A few 
 are represented in the following figures. Fig. 1 represents a 
 crystal of snow of not unfrequent occurrence, As is evident 
 
56 CRYSTALLOGRAPIY. 
 
 to the eye, it consists either of six crystals meeting in a point, 
 or of three crystals crossing one another; and besides, there are 
 numerous minute crystals regularly arranged along the rays. 
 Fig. 2 represents a cross (cruciform) crystal of staurolite, which 
 
 
 
 is similarly compound, but made up of two intersecting crys- 
 tals. Fig. 3 is a compound crystal of gypsum, and fig. 4 
 one of spinel. These will be understood from the following 
 figures. 
 
 
 
 Fig. 5 is a simple crystal of gypsum ; 
 if it be bisected along a b, and the right 
 | half be inverted and applied to the other, 
 
 4 TT COI will form fig. 3, which is therefore a 
 
 i ec twin crystal in which one half has a re- 
 
 Hl verse position from the other. Fig. 6 is 
 
 VEN a simple octahedron; if it be bisected 
 
 along, the plane abede, and the upper 
 
 half, after being revolved half way 
 
 around, be then united to the lower, it 
 
 will have the form in fig. 4. Both of these, therefore, are 
 
 similar twins, in which one of the two component parts is 
 reversed in position. 
 
 Crystals ke figs. 3 and 4 have proceeded from a compound 
 nucleus in which one of the two molecules was reversed; and 
 those like fig. 1, from a nucleus of three (or six) molecules. 
 Compound crystals of the kinds above described, thus differ 
 from simple crystals in having been formed from a nucleus 
 of two or more united molecules, instead of from a simple 
 nucleus. 
 
 Compound crystals are generally distinguished by their re-en- 
 tering angles, and often also by the meeting of striz at an angle 
 along a line on a surface of a crystal, the line indicating the 
 plane of junction of the two crystals. 
 
 Compound crystals are called twolings, threelings, fourtings, 
 according as they consist of two, three, or four united crystals. 
 
TWIN, OR COMPOUND CRYSTALS. 57 
 
 Fig. 1 represents a threeling, and 2, 3, and 4, twolings. In 3 
 and 4 the combined crystals are simply in contact along the 
 plane of junction ; in 2 they cross one another; the former are 
 called contaect-twins and the latter penetration-twins. 
 
 Besides the above, there are also geniculated crystals, as in 
 the annexed figure of a crystal of rutile. The bending has here 
 taken place at equal distances from the centre 
 of the crystal, and it must therefore have been ue 
 subsequent in time to the commencement of 
 the erystal. The prism began from a simple 
 molecule; but after attaining a certain length 
 an abrupt change of direction took place. The 
 angle of geniculation is constant in the same 
 mineral species, for the same reason that the 
 interfacial angles of planes are fixed; and it is such that a cross 
 section directly through the geniculation is parallel to the posi- 
 tion of a common secondary plane. In the figure given the 
 plane of geniculation is parallel to one of the terminal edges. 
 In rutile the geniculated crystals sometimes repeat the bendings 
 at each end until the extremities meet to form a wheel-like 
 twin. 
 
 In some species, as albite, the reversion of position on which 
 this kind of twin depends, takes place at so short intervals that 
 
 the crystal consists of parallel plates, 
 
 8. 9. each plate often less than a twen- 
 
 tieth of an inch in thickness. A sec- 
 
 tion of such a erystal, made trans- 
 
 verse to the plate, is given in fig. 8; 
 
 without the twinning the section 
 
 would have been as in fig. 9. The 
 
 plates, as the figure shows, make with 
 
 one another at their edges a re-enter- 
 
 ing angle (in albite an angle of 172° 
 
 48’), and hence a plane of the albite 
 
 crystal at right angles to the twin- 
 
 ning direction, is covered with a series of ridges and depressions 
 
 which are so minute as to be only fine striations, sometimes 
 
 requiring a magnifying power to distinguish. Such striations 
 
 in albite are therefore an indication of the compound struc- 
 ture. 
 
 This kind of twinning is owing to successive changes of 
 polarity in the molecules as the enlargement of the crystal — 
 went forward. It occurs in all the triclinic feldspars, and is a 
 means of distinguishing them from orthoclase. 
 
 
 
58 CRYSTALLOGRAPHY. 
 
 In some twin crystals the two component parts of the crystal 
 are not united by an even plane, but run 
 into one another with great irregularity. 
 Cases of this kind occur in the species of 
 quartz in twins made up of the forms It 
 and —I (or —1). In fig. 10 the shaded 
 parts of the pyramidal planes are of the 
 form —1, and the non-shaded parts of 
 R. Each of the faces is made up partly 
 of Rand partly of —1. The limits of 
 the two are easily seen on holding the 
 crystal up to the light, since the —1 
 portion is less well polished than the 
 other. In this crystal, as in other erys- 
 tals of quartz, the striations of planes t 
 are owing to oscillations between pyram- 
 idal and prismatic planes while the for- 
 mation of the latter was in progress. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 3. CRYSTALLINE AGGREGATES. 
 
 The crystalline aggregates here included are the simple, not 
 the mixed; that is, they are those consisting of crystalline in- 
 dividuals of a single species. 
 
 The crystalline individuals may be (1) distinct crystals ; (2) 
 fibres or columns ; (8) scales or lamelle; or (4) grains, either 
 cleavable or not so. E 
 
 1. Consisting of distinct crystals —The distinct crystal may 
 be either long or short prismatic, stout or slender to acicular 
 (needle-like), and capillary (hair-like) ; or they may have any 
 other forms of crystals. They may be aggregated (a) in lines ; 
 (b) promiscuously with open spaces ; (c) over broad surfaces ; 
 (d) about centres. The various kinds of aggregates thus made 
 are: 
 
 a. Filiform.—Thread-like lines of crystals, the crystals often 
 not well defined. 
 
 b. Dendritic.—Arborescent slender spreading branches, some- 
 what plant-like, made up of more or less distinct crystals, as in 
 the frost on windows, and in arborescent forms of native cop- 
 per, silver, gold, ete. 
 
 Fig. 11 represents, much magnified, an arborescent form of 
 magnetite occurring in mica at Pennsbury, in Pennsylvania. 
 Arborescent delineations over surfaces of rock are usually called 
 
ORYSTALLINE AGGREGATES. 59 
 
 dendrites. They have been formed by crystallization from a 
 solution of mineral matter which has entered by some crack and 
 spread between the layers of 
 
 the rock. They are often 11, 
 
 black, and consist of oxide 
 of manganese; others, of a 
 brownish color, are made of ee : ; 
 limonite; others, of a red- “fs 
 dish black or black color, of 0 
 hematite. Moss-like forms ES L Ce 
 also occur, aS In moss agate. salt 
 
 c, Reticulated. — Slender eal fer de 
 prismatic crystals promiscu- »~ i 
 
 ously crossing, with open BN age 
 
 spacings. es 
 
 d. Divergent.—Free crys- am ae. 
 = pS ee 
 
 tals radiating from a central 
 point. 
 
 e. Drusy.—A surface is drusy when made up of the extremi- 
 ties of small crystals. 
 
 2. Consisting of columnar individuals. 
 
 a. Columnar, when the columnar individuals are stout. 
 
 b. Fibrous, when they are slender. 
 
 ce. Parallel fibres, when the fibres are parallel. 
 
 d. Radiated, when the columns or fibres radiate from 
 centres. 
 
 e. Stellated, when the radiations from a centre are equal 
 around, so as to make star-like or circularly-radiated groups. 
 
 Globular, when the radiated individuals make globular or 
 hemispherical forms, as in wavellite. 
 
 g. Botryoidal, when the globular forms are in groups, a lit- 
 tle like a bunch of grapes. The word is from the Greek for a 
 bunch of grapes. 
 
 h. Mammillary, having a surface made up of low and broad 
 prominences. The term is from the Latin mammilla, a litile 
 teat. 
 
 i. Coralloidal, when in open-spaced groupings of slender 
 stems, looking like a delicate coral. A result of successive ad- 
 ditions at the extremity of a prominence, lengthening it into 
 cylinders, the stems generally having a faintly radiated struc- 
 ture. 
 
 Specimens of all these varieties of columnar structure, except- 
 ing the last, often have a drusy surface, the fibres or columns 
 ending in projecting crystals. 
 
60 CRYSTALLOGRAPHY. 
 
 3. Consisting of scales or lamelle. 
 
 a. Plumose, having a divergent arrangement of scales, as 
 seen on a surface of fracture; ¢. g., plumose mica. 
 
 b. Lamellar, tabular, consisting of flat lamellar crystalline in- 
 dividuals, superimposed and adhering. 
 
 c. Micaceous, having a thin fissile character, due to the aggre- 
 gation of scales of a mineral which, like mica, has eminent 
 cleavage. 
 
 d. Septate, consisting of openly-spaced intersecting tabular 
 individuals ; also divided into polygonal portions by reticulat- 
 ing veins or plates. A septarium is a concretion, usually flat- 
 tened spheroidal in shape, the solid interior of which is inter- 
 sected by partitions; these partitions are the fillings of cracks 
 in the interior that were due to contraction on drying. When 
 the surface of such septate concretions has been worn off, they 
 often have the appearance of a turtle’s back, and are sometimes 
 taken for petrified turtles. 
 
 4. Consisting of grains. Granular structure, A massive 
 mineral may be coarsely granular or finely granular, as in 
 varieties of marble, granular quartz, etc. It is termed saccha- 
 roidal when evenly granular, like loaf sugar. Jt may also be 
 cryptocrystalline, that is, having no distinct grains that can 
 be detected by the unaided eye, as in flint. The term crypto- 
 crystalline is from the Greek for concealed crystalline. Aphani- 
 tic, from the Greek for invisible, has the same signification. The 
 term ceroid is applied when this texture is connected with a 
 waxy lustre, as in some common opal. 
 
 Under this section occur also globular, botryoidal, and mam- 
 millary forms, as a result of concretionary action in which no 
 distinct columnar interior structure is produced. ‘They are 
 called pisolitic when in masses consisting of grains as large as 
 peas (from the Latin piswm, a pea), and odlitic when the grains 
 are not larger than the roe of a fish, from the Greek for egg. 
 
 5. Lorms depending on mode of deposition.—Besides the 
 above, there are the following varieties which have come from 
 mode of deposition : 
 
 a. Stalactitic, having the form of a cylinder, or cone, hang- 
 ing from the roofs of cavities or caves. The term stalactite is 
 usually restricted to the cylinders of carbonate of calcium hanging 
 from the roofs of caverns; but other minerals are said to have 
 a stalactitic form when resembling these in their general shape 
 and origin. Chalcedony and brown iron ore are often stalacti- 
 tic. Interiorly the structure may be either granular, radiately 
 fibrous, or concentric, 
 
CRYSTALLINE AGGREGATES. OL 
 
 b. Concentric.—When consisting of lamelle, lapping one 
 over another around a centre, a result of successive concretion- 
 ary aggregations, as in many concretionary forms, most prsolite, 
 part of odlite, some stalactites, etc.. 
 
 c, Stratified, consisting of layers, as a result of deposition : 
 
 é. g-, some travertine, or tufa. 
 _d. Banded ; color-stratified. Like stratified in origin, but 
 the layers usually indicated only by variations in color ; the band- 
 ing is shown in a transverse section: ¢. g., agate, much stalag- 
 mite, riband jasper. 
 
 e. Geodes.—When a cavity has been lined by the deposition 
 of mineral matter, but not wholly filled, the enclosing mineral 
 is called a geode. The mineral is often banded, owing to the 
 successive depositions of the material, and frequently has its 
 inner surface set with crystals. Agates are often slices or frag- 
 ments of geodes. 
 
 6. Forms derived from the crystals of other minerals. Pseu- 
 domorphs.—Crystalline aggregates, especially the granular, 
 sometimes have forms derived from the crystals of other 
 minerals either 
 
 (1) Because a result of cotemporaneous removal and substi- 
 tution 5 or 
 
 (2) Because a result of the alteration of such crystals; or 
 
 (3) Because filling spaces that had been left occupied in con- 
 sequence of previous removal. 
 
 For example. Crystals occur having the forms of calcite 
 (calcium carbonate, or “ carbonate of lime ”’), but consisting of 
 quartz or silica. They were made from calcite crystals by the 
 action of some solution containing silica, the solution dissolving 
 away the calcite and depositing at the same time silica or quartz. 
 Specimens occur showing all stages in the change from the ear- 
 liest in which the calcite is thinly coated with quartz, to the 
 last, in which it is all quartz. Such crystals are pseudomorphs 
 of quartz after calcite. Siliceous fossil shells and corals are 
 similar pseudomorphs after calcite, since shells and corals con- 
 sist chiefly of calcite. Other quartz pseudomorphs have the 
 form of fluorite, barite, etc. 
 
 Again, the forms of calcite occur with the constitution of 
 limonite, a hydrous iron oxide. In such a case the iron oxide 
 was in the solution that corroded and dissolved away the 
 calcite. 
 
 Again, the forms of calcite occur with the constitution of 
 serpentine, a hydrous magnesium silicate ; and in this case the 
 ingredients of the serpentine silicate were present when the 
 
§2 CRYSTALLOGRAPUY. 
 
 calcite was dissolved away by the corrosive solvent, and took 
 its place as the calcite particles were removed. 
 
 In all the above cases the pseudomorphs were made by simple 
 removal and cotemporaneous substitution. 
 
 Again, crystals of the form of chrysolite, a magnesium sili- 
 cate, occur, altered to serpentine, a hydrous magnesium silicate. 
 Here the pseudomorph was made by a process of alteration, 
 part of the ingredients remaining, and only water added. 
 
 Again, crystals of siderite (spathic iron or iron carbonate) 
 occur changed to limonite, a hydrous iron oxide. Here there 
 was an oxidation of the iron of the carbonate, and the addition 
 of water. This is another example of pseudomorphs by altera- 
 tion. Similarly orthoclase changes to kaolin, and kaolin has 
 the form at times of orthoclase crystals. 
 
 Again, crystals of the form of those of common salt occur 
 consisting of clay or of calcite, which were made by deposition 
 in a cavity left by the dissolving away of an imbedded crystal 
 of salt. These are pseudomorphs by deposition. 
 
 Again, crystals of aragonite, prismatic calcium carbonate, 
 occur consisting of calcite or rhombohedral calcium carbon- 
 ate; and here there is a change in crystallization without any 
 change of chemical composition. 
 
 7. Hracture.—Kinds of fracture in these crystalline aggre- 
 gates depend on the size and form of the particles, their cohe- 
 sion, and to some extent their having cleavage or not. 
 
 Among granular varieties, the influence of cleavage is in all 
 cases very small, and in the finest almost or quite nothing. The 
 term hackly is used for the surface of fracture of a metal, when 
 the grains are coarse, hard, and cleavable, so as to be sharp 
 and jagged to the touch ; even, for any surface of fracture when 
 it is nearly or quite flat, or not at all conchoidal; conchoidal, 
 when the mineral, owing to its extremely fine or cryptocrystal- 
 line texture and hardness, breaks with shallow concavities and 
 convexities over the surface, as in the case of flint. The word 
 conchoidal is from the Latin concha, a shell. These kinds of 
 fracture are not of much importance in mineralogy, since they 
 distinguish varieties of minerals only, and not species, 
 
HARDNESS—-TENACITY—SPECIFIC GRAVITY. 63 
 
 9. PHYSICAL PROPERTIES OF 
 MINERALS. 
 
 Tue physical properties referred to in the description and. 
 determination of minerals are here treated under the following 
 heads: (1) Hardness; (2) Tenacity; (8) Specific Gravity ; 
 (4) Refraction, Polarization; (5) Diaphaneity, Color, Lustre; 
 (6) Electricity and Magnetism; (7) ‘laste and Odor. 
 
 1. HARDNESS. 
 
 The comparative hardness of minerals is easily ascertained, 
 and should be the first character attended to by the student in 
 examining a specimen. It is only necessary to draw a file 
 across the specimen, or to make trials of scratching one with 
 another. As standards of comparison the following minerals 
 have been selected, increasing gradually in hardness from talc, 
 which is very soft and easily cut with a knife, to the diamond. 
 This table, called the scale of hardness, is as follows : 
 
 1, tale, common foliated variety; 2, rock salt ; 3, calcite, 
 transparent variety ; 4, fluorite, crystallized variety ; 5, apatite, 
 transparent crystal ; 6, orthoclase, cleavable variety 5 7, quartz, 
 transparent variety ; 8, topaz, transparent crystal; 9, sapphire, 
 cleavable variety ; 10, diamond. 
 
 If, on drawing a file across a mineral, it is impressed as easily 
 as fluorite, the hardness is said to be 4; if as easily as ortho- 
 _clase, the hardness is said to be 6; 1f more easily than ortho- 
 clase, but with more difficulty than apatite, its hardness is de- 
 scribed as 54 or 5°. 
 
 The file should be run across the mineral three or four times, 
 and care should be taken to make the trial on angles equally 
 blunt, and on parts of the specimen not altered by exposure. 
 Trials should also be made by scratching the specimen under 
 examination with the minerals in the above scale, since some- 
 times, owing to a loose aggregation of particles, the file wears 
 down the specimen rapidly, although the particles are very 
 hard. 
 
 In crystals the hardness is sometimes appreciably different in 
 degree in the direction of different axes. In erystals of mica 
 
64 PHYSICAL PROPERTIES OF MINERALS, 
 
 the hardness is less on the basal plane of the prism, that is, on 
 the cleavage surface, than it is on the sides of the prism. On 
 the contrary, the terminaticn of a crystal of eyanite is harder 
 than the lateral planes. The degree of hardness in different 
 directions may be obtained with great accuracy by means of an 
 instrument called a sclerometer. 
 
 2. TENACITY: 
 
 The following rather indefinite terms are used with reference 
 to the qualities of tenacity, malleability, and flexibility in min- 
 erals : 
 
 1. Brittle. —When a mineral breaks easily, or when parts of 
 the mineral separate in powder on attempting to cut it. 
 
 2. Malleable.—When slices may be cut off, and these slices 
 will flatten out under the hammer, as in native gold, silver, 
 copper. 
 
 3. Sectile—When thin slices may be cut off with a knife. 
 All malleable minerals are sectile. Argentite and cerargyrite 
 are examples of sectile ores of silver. The former cuts nearly 
 like lead and the latter nearly like wax, which it resembles. 
 Minerals are imperfectly sectile when the pieces cut off pul- 
 verize easily under a hammer, or barely hold together, as sele- 
 nite. 
 
 4. Flexible. —When the mineral will bend, and remain bent 
 after the bending force is removed. Example, talc. 
 
 5. Elastic.—When, after being bent, it will spring back to 
 its original position, Example, mica. 
 
 A liquid is said to be viscous when on pouring it the drops 
 lengthen and appear ropy. Example, petroleum. ; 
 
 3. SPECIFIC GRAVITY. 
 
 The specific gravity of a mineral is its weight compared with 
 that of some substance taken as a standard. For solids and 
 liquids distilled water, at 60° F., is the standard ordinarily 
 used; and if a mineral weighs twice as much as water, its spe- 
 cific gravity is 2; if three times itis three. It is then necessary 
 to compare the weight of the mineral with the weight of an 
 equal bulk of water. The process is as follows : 
 
 First weigh a fragment of the mineral in the ordinary way, 
 
SPECIFIC GRAVITY. 65 
 
 with a delicate balance; next suspend the mineral by a hair, or 
 fibre of silk, or a fine platinum wire, to one of the scales, im- 
 merse it thus suspended in a glass of distilled water (keeping 
 the scales clear of the water) and weigh it again; subtract the 
 second weight from the jirst, to ascertain the loss by immersion, 
 and divide the jirst by the difference obtained ; the result is the 
 specific gravity. The loss by immersion is equal to the weight 
 of an equal volume of water. The trial should be made ona 
 small fragment; two to five grains are best. ‘The specimen 
 should be free from impurities and from pores or air-bubbles. 
 Tor exact results the temperature of the water should be noted, 
 and an allowance be made for any variation from the height of 
 thirty inches in the barometer. The observation is usually 
 made with the water at a temperature of 60° F.; 39°°5 F., the 
 temperature of the maximum density of water, is preferable. 
 
 The accompanying figure represents the 
 spiral balance of Jolly, by which the weight 
 is measured by the torsion of a spiral brass 
 wire. On the side of the upright (4) which 
 faces the spiral wire, there is a graduated 
 mirror, and the readings which give the 
 weight of the mineral in and out of water are 
 made by means of an index (at m) connected 
 with the spiral wire; and its exact height, 
 with reference to the graduation, is obtained 
 by noting the coincidence between it and 
 its image as reflected by the graduated mir- 
 ror.c and dare the pans in which the piece 
 of mineral is placed, first in c, the one out 
 of the water, and then in d, that in the 
 water. 
 
 Another process, and one available for 
 porous as well as compact minerals, is per- 
 formed with a light glass bottle, capable of 
 holding exactly a thousand grains (or any 
 known weight) of distilled water. The 
 specimen should be reduced to a coarse pow- 
 der. Pour out a few drops of water from 
 the bottle and weigh it; then add the pow- 
 dered mineral till the water is again to the brim, and reweigh 
 it; the difference in the two weights, divided by the loss of 
 water poured out, is the specific gravity sought. The weight 
 of the glass bottle itself is here supposed to be balanced by an 
 equivalent weight in the other scale. 
 
 D 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
65 PHYSICAL PROPERTIES OF MINERALS. 
 
 4, REFRACTION anp POLARIZATION. 
 
 Minerals differ widely in their refracting and polarizing | 
 properties, and hence these properties are a convenient means 
 of distinguishing species. The explanations of the subject, and 
 the methods of careful experimenting, will be found in treatises 
 on optics, and algo at considerable length, and with minute 
 directions as to the use of instruments, in the Text-Book of 
 Mineralogy. Only a few of the simpler facts required for the 
 ordinary purposes of the mineralogist are here mentioned. 
 
 The character of the refraction varies according to the sys- 
 tem of crystallization. 
 
 A. In isometric crystals there is simple refraction alike in 
 all directions, and no polarization. 
 
 B. In dimetric and hexagonal crystals the vertical axis, or 
 axis of symmetry, is the direction of the optic axis ; in all 
 directions except this a transmitted ray of light 1s doubly re- 
 fracted. Such crystals are optically uniaxial. 
 
 C. In trimétric, monoclinic, and triclinic crystals, which 
 have the three axes unequal, there are ¢wo directions of no 
 double-refraction. Such crystals are optically biaxial. 
 
 1. Isometric System.—In the isometric system there is no 
 reference whatever in the refraction to crystalline structure, 
 and in this respect substances thus crystallizing are like water. 
 There is only simple refraction. The index of refraction is ob- 
 tained by dividing the sine of the angle of incidence of a ray of 
 light by the sine of its angle of refraction. ‘Thus if a ray of 
 light strike the surface of a transparent plate of the mineral at 
 an angle of 40° from the perpendicular, and then passes through 
 the plate at an angle of 30° from the perpendicular, owing to 
 the refraction, the sine of 40° divided by the sine of 30° will 
 be the index of refraction. Now the index of refraction of air 
 being made the unit, that of water is 1330 5 of fluorite, 1°4345 
 of rock salt, 1:557; of spinel, 1-764; of garnet, 1:815; of 
 blende, 2°260; of diamond, 27489. 
 
 9. Crystals Uniaxial in Polarization.—A transparent cleav- 
 age plate from a crystal of calcite shows what is called double 
 refraction. Placed over a line drawn on any surface, two 
 parallel lines are seen, one produced by the ordinary ray, and 
 the other by the extraordinary ray. Both rays are polarized, 
 and in planes at right angles to each other. Prisms, called 
 Wicol prisms, made from transparent calcite (Iceland Spar), 
 are employed for obtaining polarized light. ‘Transparent 
 
REFRACTION AND POLARIZATION. 67 
 
 ‘plates of tourmaline, cut from a crystal parallel to the vertical 
 axis, also are used for this purpose. Another method of ob- 
 taining it is by reflection—light, when reflected at a certain 
 angle from a polished surface, being polarized; the angle of 
 reflection differs for different substances. 
 
 
 
 The above figure represents a simple polariscope made with 
 two tourmaline plates, which is ‘convenient for many ordinary 
 observations. The best instruments for the purpose are made 
 with Nicol prisms, and are adapted to microscopic work. ‘The 
 prisms, placed within the tube of the instrument, one of them 
 below the stage, are arranged so as to admit of revolution; and 
 the stage also has a graduated circle and revolves. ‘The com- 
 pound microscope also is often converted into a polariscope by 
 Nicol prisms arranged for this purpose. 
 
 When a crystal with one axis of polarization, as, for example, 
 calcite, is examined by means of a ray of polarized light passed in 
 the direction of the vertical axis, concentric circular rings are 
 seen, having the colors of the spectrum intersected by either a 
 black or a white cross, as in figs. 1, 2. To make the observa- 
 
 te 3. 
 
 = 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 tion it is necessary that the calcite crystal should have its ex- 
 tremities polished at right angles to the vertical axis. IPfa 
 tourmaline plate be placed against_or near one of its polished 
 
68 PHYSICAL PROPERTIES OF MINERALS. 
 
 faces, and a similar tourmaline plate in front of the opposite 
 face, the colored rings will be seen on looking through ; and by 
 revolving one of the tourmaline plates a change will be observed 
 ‘at each 90° of revolution, in the colors of the rings, and in the 
 variations in appearance of the cross from black to white, and 
 the reverse. The fact in any case that the rings of color are 
 perfect circles, and the black cross a symmetrical one, is proof 
 that the crystal is either of the dimetrie or hexagonal system. 
 But sometimes very exact observation is necessary to deter- 
 mine the truth. 
 
 3. Crystals Biawial in Polarization.—Biaxial crystals arc | 
 those having two optic axes, and the angle between them is 
 called the axial angle. 
 
 When a section of such a crystal, at right angles to the line 
 bisecting the acute axial angle, is viewed in converging polar- 
 ized light, the two axes are seen with a series of elliptical col- 
 ored rings surrounding each. If the section is so placed that 
 the line joining the axes coincides with the vibration-plane of 
 either Nicol prism, or tourmaline plate, an unsymmetrical 
 
 6. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 FREE 
 Ss 
 = 
 
 
 
 
 
 
 
 
 
 
 Te 
 gency 
 i ii 
 Sil cll iio \ 
 Se 
 
 UTAH su AG AT 
 
 (ay wield’ c 
 
 Nill 
 "tan 
 
 | {| ( { I if 
 
 Ml ne 
 ) 
 
 GLAUBER SALT. PHLOGOPITE, ANTWERP, N. Y. 
 
 
 
 black cross is also seen, as in fig. 4; if it makes an angle of 45° 
 with this, two curved black bars are observed, as infig, 5. In 
 either case the colors are reversed, and the black changed to 
 white as one of the Nicols is revolved. Fig. 6 shows the 
 axial figure for phlogopite (in the second position mentioned 
 above) where the axial angle is very small. The rings are less 
 numerous and farther apart the thinner the section that is 
 employed in making the observations. 
 
 In muscovite (common mica) the angle between the axes is 
 50° to 70°, and, if the tourmaline tongs are employed, the two 
 
REFRACTION AND POLARIZATION. 69 
 
 series of rings are visible only when viewed in directions very 
 oblique to one another. 
 
 4. Circular Polarization in Uniaxial Crystals.—It is stated 
 on page 58 that quartz crystals have often a left-handed and a 
 right-handed arrangement of planes. This is connected with a 
 right-handed and left-handed molecular structure in crystals of 
 this species. When a plate cut at right angles to the axis 1s ex- 
 amined by the polarized light, instead of presenting a black 
 cross, the centre of the rings appears brightly colored, and if the 
 polarizer is revolved, this color changes from blue to yellow, 
 then red, right-handed crystals requiring revolution to the 
 right and left-handed to the left for this succession. This prop- 
 erty seems to distinguish the smallest grains of quartz, and may 
 be easily observed in a good polariscope. 
 
 5. Anomalies in Polarization.—There are some isometric 
 crystals which have the property of polarization. Boracite is 
 one example; and it is explained by the presence of another 
 mineral in minute particles, distributed regularly through the 
 crystals. Perofskite is another case ; and it has suggested a 
 doubt as to its being isometric. Octahedrons of alum some- 
 times have polarization, and it has 
 been shown to be due to the crystals 
 being made up of thin plates—light, 
 when transmitted through a pile of 
 such plates, becoming polarized. Dia- 
 monds are sometimes uniaxial. 
 
 Analcite was long since described 
 by Sir David Brewster as an example 
 of polarization under the isometric 
 system. Its trapezohedrons exhibit 
 a symmetrical arrangement of lines of 
 prismatic colors and alternating dark 
 lines with cross-bands, as imperfectly 
 shown in the annexed figure. Trapezohedrons of leucite are 
 somewhat similar in their polarizing character. The effect in 
 both species is connected with twinning ; but, besides, accord- 
 ing to recent observers, the crystallization is dimetric. One 
 writer makes crystals of analcite to be ¢rimetric twins, analogous 
 those of phillipsite. Twinning in crystals is a very common 
 source of irregularities. A regular twinning of laminz of bi- 
 axial crystals around a centre may give a uniaxial character to 
 the twin. Apophyllite is a dimetric species, showing peculiari- 
 ties in its colors arising from the different action of the mineral 
 in light of different colors. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
50 PHYSICAL PROPERTIES OF MINERALS. 
 
 5. DIAPHANEITY, LUSTRE, COLOR. 
 1. DIAPHANEITY. 
 
 Diaphaneity is the property which many objects possess of 
 transmitting light; or, in other words, of permitting more or 
 less light to pass through them. This property is often called 
 transparency, but transparency is properly one of the degrees 
 of diaphaneity. The following terms are used to express the 
 different degrees of this property : 
 
 Transparent—a mineral is said to be transparent when the 
 outlines of objects, viewed through it, are distinct. Example, 
 class, crystals of quartz. 
 
 Subtransparent, or semitransparent—when objects are seen 
 but their outlines are indistinct. 
 
 Translucent—when light is transmitted, but objects are not 
 seen. Loaf sugar is a good example ; also Carrara marble. 
 
 Subtranslucent—when merely the edges transmit light faintly. 
 
 When no light is transmitted the mineral is described as 
 
 opaque. 
 2. LUSTRE. 
 
 The lustre of minerals depends on the nature of their surfaces, 
 which causes more or less light to be reflected. There are dif- 
 ferent degrees of intensity of lustre, and also different kinds of 
 lustre. 
 
 a. The kinds of lustre are six, and are named from some 
 familiar object or class of objects. 
 
 1. Metallic—the usual lustre of metals. Imperfect metallic 
 lustre is expressed by the term swbmetallie. 
 
 2. Vitreous—the lustre of broken glass. An imperfect 
 vitreous lustre is termed subvitreous. Both the vitreous and 
 subvitreous lustres are common. Quartz possesses the former 
 in an eminent degree; calcareous spar often the latter. This 
 kind of lustre may be exhibited by minerals of any color. 
 
 3. Resinous—lustre of the yellow resins. Example, some 
 opal, zinc blende. 
 
 4, Pearly—like pearl. Example, talc, native magnesia, stil- 
 bite, etc. When united with submetallic lustre the term 
 metallic-pearly is applied. 
 
 5. Silky—like silk; it is the result of a fibrous structure. 
 
DIAPHANEITY —LUSTRE—COLOR. 71 
 
 Example, fibrous calcite, fibrous gypsum, and many fibrous 
 minerals, more especially those which in other forms have a 
 pearly lustre. 
 
 6. Adamantine—the lustre of the diamond. When sub- 
 metallic, it is termed metallic adamantine. Example, some 
 varieties of white lead ore or cerussite. 
 
 b. The degrees of intensity are denominated as follows: 
 
 1. Splendent—when the surface reflects light with great bril- 
 liancy and gives well-defined images. Example, Elba hematite, 
 tin ore, some specimens of quartz and pyrite. 
 
 2. Shining—when an image 1s produced, but not a well-de- 
 fined image. Example, calcite, celestite. 
 
 3. Glistening—when there is a general reflection from the 
 ‘surface, but no image. Example, talc. 
 
 4. Glimmering—when the reflection is very imperfect, and 
 apparently from points scattered over the surface. Example, 
 flint, chalcedony. 
 
 A mineral is said to be dull when there is a total absence cf 
 lustre. Example, chalk. 
 
 3; CoLoR: 
 
 1. Kinds of Color.—In distinguishing minerals, both the ex- 
 ternal color and the color of a surface that has been rubbed or 
 scratched, are observed. The latter is called the streak, and the 
 powder abraded, the streak-powder. 
 
 The colors are either metallic or unmetallre. 
 
 The metallic are named after some familiar metal, as copper- 
 red, bronze-yeilow, brass-yellow, gold-yellow, steel-gray, lead- 
 gray, lron-gray. 
 
 The unmetallic colors used in characterizing minerals are 
 various shades of white, gray, black, blue, green, yellow, red and 
 brown. 
 
 There are thus snow-white, reddish-white, greenish-white, 
 milk-white, yellowish-white. 
 
 Bluish-gray, smoke-gray, greenish-gray, pearl-gray, ash-gray. 
 
 Velvet-black, greenish-black, bluish-black, grayish-black. 
 
 Azure-blue, violet-blue, sky-blue, indigo-blue. 
 
 ' Emerald-green, olive-green, oil-green, grass-green, apple-green, 
 blackish-green, pistachio-green (yellowish). 
 
 Sulphur-yellow, straw-yellow, wax-yellow, ochre-yellow, 
 honey-yellow, orange-yellow. 
 
 Scarlet-red, blood-red, flesh red, brick-red, hyacinth-red, rose- 
 red, cherry-red. 
 
72 PHYSICAL PROPERTIES OF MINERALS. 
 
 Hair-brown, reddish-brown, chestnut-brown, yellowish-brown, 
 pinchbeck-brown, wood-brown. 
 
 A play of colors—this expression is used when several pris- 
 matic colors appear in rapid succession on turning the mineral. 
 The diamond is a striking example; also precious opal. 
 
 Change of colors—when the colors change slowly on turning 
 An different positions, as in labradorite. 
 
 Opalescence—when there is a milky or pearly reflection 
 from the interior of a specimen, as in some opals, and in cat’s 
 eye. 
 
 LIridescence—when prismatic colors are seen within a crystal, 
 it is the effect of fracture, and is common in quartz. 
 
 Tarnish—when the surface colors differ from the interior ; 
 it is the result of exposure. The tarnish is described as irised 
 when it has the hues of the rainbow. 
 
 2. Dichroism, Trichroism.—Some crystals, under each of the 
 systems excepting the isometric, have the property of present- 
 ing different colors by transmitted light in different directions. 
 The property is called dichroism when these colors are seen in 
 two directions, and trichroism (or pleochroism) if seen in three 
 directions. The colors are always the same in the direction 
 of equal axes and often unlike in the direction of unequal 
 axes. As dimetric and hexagonal crystals have the lateral axes 
 equal they can present different colors only in two directions, 
 the vertical and lateral; while all crystals that are optically 
 biaxial may be trichroic. 
 
 The mineral iolite is a noted example, and received the name 
 dichroite on account of this property. Transparent colored 
 crystals of tourmaline, topaz, epidote, mica, diaspore, and many 
 other species exhibit it. Tourmaline crystals, when transpar- 
 ent or translucent transverse to the prism, are opaque in the 
 direction of the vertical axis; and so also are thick crystals of 
 mica. Colored varieties of hornblende are dichroic, while 
 those of the related mineral, pyroxene, are not so. 
 
 This quality is best observed by means of pelarized light. On 
 examining a mineral with a tourmaline plate, or Nicol prism, the 
 two colors in a dichroic mineral are successively seen as the 
 tourmaline or Nicol is revolved; and if there is no dichroism 
 there is no change of color. A small instrument, containing a 
 prism of calcite, has been constructed for showing the dichro- 
 ism, called the dichroscope. On looking through it at a di- 
 chroic crystal, the aperture against the crystal appears double, 
 owing to the double refraction of the calcite, one image being 
 made by the ordinary ray and the other by the extraordinary 
 
ELECTRICITY AND MAGNETISM. 73 
 
 ray and the two colors are seen side by side, at intervals of 
 90° in the revolution of the mineral. 
 
 For opaque minerals it is necessary to make a thin transparent 
 section of the mineral and examine it with a polariscope, or with 
 a microscope arranged to act as one by the addition of one Nicol 
 prism. The opaque hornblende of rocks is thus distinguished 
 from pyroxene, and so in other cases. 
 
 3. Asterism.—Some crystals, especially the hexagonal, when 
 viewed in the direction of the vertical axis, present peculiar re- 
 flections in six radial directions. This arises either from pecu- 
 liarities of texture along the axial portions, or from some im- 
 purities. A remarkable example of it is that of the asteriated 
 sapphire, and the quality adds much to its value as a gem. 
 The six rays are sometimes alternately shorter, indicating the 
 rhombohedral character of the crystal. 
 
 4, Phosphorescence.—Several minerals give out light either 
 by friction or when gently heated. This property of emitting 
 light is called phosphorescence. 
 
 Two pieces of white sugar struck against one another give a 
 feeble light, which may be seen in a dark place. The same 
 effect is obtained on striking together fragments of quartz, and 
 even the passing of a feather rapidly over some specimens of 
 zine blende is sufficient to elicit light. . 
 
 Fluorite is the most convenient mineral for showing phos- 
 phorescence by heat. On powdering it, and throwing it ona 
 plate of metal beated nearly to redness, the whole takes on a 
 bright glow. In some varieties the light is emerald green 5 in 
 others, purple, rose, or orange. A massive fluor, from Hun- 
 tington, Connecticut, shows beautifully the emerald green phos- 
 phorescence. 
 
 Some kinds of white marble, treated in the same way, give 
 out a bright yellow light. 
 
 After being heated for a while the mineral loses its phos- 
 phorescence ; but a few electric shocks will, in many cases, to 
 some degree restore it again. 
 
 6. ELECTRICITY, anp MAGNETISM. 
 
 E.ectricity.—Many minerals become electrified on being 
 rubbed, so that they will attract cotton and other light sub- 
 stances ; and when electrified some exhibit positive and others 
 negative electricity, when brought near a delicately suspended 
 magnetic needle. The diamond, whether polished or not, al- 
 
74. PHYSICAL PROPERTIES OF MINERALS. 
 
 ways exhibits positive electricity, while other gems become 
 negatively electric in the rough state, and positively only in the 
 polished state. Some minerals, thus electrified, retain the power 
 of electric attraction for many hours, as topaz, while others lose 
 it in a few minutes. 
 
 Many minerals become electric when heated, and such species 
 are said to be pyro-electric, from the Greek pur, fire, and 
 electric. 
 
 A prism of tourmaline, on being heated, becomes polar; one 
 extremity will be attracted, the other repelled, by a pole ofa 
 strong magnet. The prisms of tourmaline have different second- 
 ary planes at the two extremities. 
 
 Several other minerals have this peculiar electric property, 
 especially boracite and topaz, which, like tourmaline, are hema- 
 hedral in their modifications. Boracite crystallizes in cubes, 
 with only the alternate solid angles similarly replaced (figs. 39, 
 40, page 25). Each solid angle, on heating the crystals, be- 
 comes an electric pole; the angles diagonally opposite are dif- 
 ferently modified and have opposite polarity. Pyroelectricity 
 has been observed also in crystals that are not hemihedral, and 
 in many mineral species. In some cases the number of poles is 
 more than two. In prehnite crystals a large series occur dis- 
 tributed over the surface. 
 
 MaGNETISM.—The name Lodestone is given to those specimens 
 of an ore of iron, called magnetite which have the power of at- 
 traction like a magnet; it is common in many beds of magnetite. 
 ‘When mounted like a horse-shoe magnet, a good lodestone will 
 lift a weight of many pounds. This is the only mineral that 
 has decided magnetic attraction. But several ores containing 
 iron are attracted by the magnet, or, when brought near a 
 magnetic needle, will cause it to vibrate; and moreover, the 
 metals nickel, cobalt, manganese, palladium, platinum and os- 
 mium, have been found te be slightly magnetic. 
 
 Many minerals become attractable by the magnet after being 
 heated that are not so before heating. This arises from a 
 change of part or all of the iron to the magnetic oxide. 
 
 ” TASTE anp ODOR. 
 
 Taste belongs only to the soluble minerals; the kinds are— 
 1. Astringent—the taste of vitriol. 
 
 2. Sweetish-astringent—the taste of alum. 
 
 3. Saline—taste of common salt. 
 
St 
 
 TASTE AND ODOR. 
 
 =I 
 
 4, Alkaliné—taste of soda. 
 
 5. Cooling—taste of saltpetre. 
 
 6. Bitter—taste of epsom salts. 
 
 7. Sowr—taste of sulphuric acid. 
 
 Odor is not given off by minerals in the dry, unchanged 
 state, except in the case of a few gases and soluble minerals. 
 By friction, moistening with the breath, the action of acids and 
 the blowpipe, odors’ are sometimes obtained, which are thus 
 designated : 
 
 1. Alliaceous—the odor of garlic. It is the odor of burning 
 arsenic, and is obtained by friction, and more distinctly by 
 means of the blowpipe, from several arsenical ores. 
 
 2. Horse-radish odor—the odor of decaying horse-radish. It 
 is the odor of burning selenium, and is strongly perceived when 
 ores of this metal are heated before the blowpipe. 
 
 3. Sulphureous—odor of burning sulphur. Friction will 
 elicit this odor from pyrites, and heat from many sulphides. 
 
 4. Fetid—the odor of rotten eggs or sulphuretted hydrogen. 
 It is elicited by friction from some varieties of quartz and lime- 
 stone. 
 
 5. Argillaceous—the odor of moistened clay. It is given off 
 by serpentine and some allied minerals when breathed upon, 
 Others, as pyrargillite, afford it when heated. 
 
76 CHEMICAL PROPERTIES OF MINERALS. 
 
 3. CHEMICAL PROPERTIES OF 
 ~ MINERALS. 
 
 Tux chemical properties of minerals are of two kinds. (1) 
 Those of the chemical composition of minerals, (2) those de- 
 pending on their chemical reactions, with or without fluxes, in- 
 cluding results obtained by means of the blowpipe. 
 
 1. CHEemMIcAL CoMPOSITION. 
 
 All the elements made known by chemistry are found in 
 minerals, for the mineral kingdom is the source of whatever 
 living beings—plants and animals—contain or use. A list of 
 these elements, as at present made out, is contained in the fol- 
 lowing table, together with the symbol for each used in stating 
 the composition of substances. These symbols are abbreviations 
 of the Latin names for the elements. A few of these Latin 
 names differ much from the English, as follows : 
 
 Stibium Sb = Antimony | Kalium K = Potassium 
 Cuprum Cu = Copper Argentum Ag = Silver 
 Ferrum Fe = Iron Natrium Na = Sodium 
 Plumbum Pb = Lead Stannum Sn = Tm 
 
 Hydrargyrum Hg = Mercury Wolframium W = Tungsten 
 
 TABLE OF THE ELEMENTS. 
 
 Aluminum Al 27-4 | Columbium (Niobium) Cb (Nb) 94 
 Antimony Sb 120 | Copper Cu 63°4 
 Arsenic As 75 | Didymium D 144°8 
 Barium ~ Ba 187 | Erbium E 168-9 
 Bismuth Bi 210 | Fluorine F 19 
 Boron B 11 Gallium Ga 68 ? 
 Bromine Br 80 | Glucinum (Beryllium) G (Be) 94 
 Cadmium Cd 112 |Gold An 197 
 Cesium Cs 133 | Hydrogen H 1 
 Calcium Ca 40 | Indium In 113°4 
 Carbon C 12 | Iodine I 127 
 Cerium Ce 138 | Jridium Ir 198 
 Chlorine Cl 35°5 | Iron Fe 56 
 Chromium Cr 52-2 | Lanthanum La 139 
 Cobalt Co 207 
 
 58°8 | Lead Pb 
 
CHEMICAL COMPOSITION OF MINERALS. 
 
 
 
 Lithium Li + 7 | Silver Ave. LOS 
 Magnesium Mg 24 | Silicon Si 28 
 Manganese Mn 55 | Sodium Na 23 
 Mercury Hg 200 | Strontium Sr 87°6 
 Molybdenum Mo 96 | Sulphur S) 32 
 Nickel Ni 58°8 | Tantalum Lae 182 
 Nitrogen N 14 | Tellurium Te 128 
 Osmium Os 199°2 | Thallium a4) 204 
 Oxygen O 16 | Thorium Th 235 
 Palladium Poa” 106°6 | Tin Sn 118 
 Phosphorus P 31 | Titanium a 50 
 Platinum Pt 197°6) Tungsten W 184 
 Potassium K 39:1 | Uranium U 240 
 Rhodium Ro 104:4) Vanadium V 51°2 
 Rubidium Rb 85°4 | Yttrium Y 92 
 Ruthenium Ru = 104-4) Zinc Zn 65:2 
 Selenium Se 79°4' Zirconium Zr 89°6 
 
 The combining weights indicate the proportions in which the 
 elements combine. Thus, assuming hydrogen, the lightest of 
 the elements, to be 1, or the unit of the series, the combining 
 weight of oxygen is 16; of iron, 56; of magnesium, 243 of 
 sulphur, 32; and so on. When hydrogen and oxygen combine 
 it is in the ratio of 2 pounds of hydrogen, or else | pound of 
 hydrogen, to 16 pounds of oxygen, and two different compounds 
 thus result. When oxygen and magnesium combine it is in the 
 ratio of 16 pounds of oxygen to 24 of magnesium. Oxygen and 
 iron combine in the ratio of 16 of oxygen to 56 of iron; or of 24 
 of oxygen (14 times 16) to 56. Sulphur and oxygen combine in 
 ‘the ratio of 32 of oxygen to 32 of sulphur; or of 48 to 32 of 
 sulphur. The combining weights are often called the atomic 
 weights. 
 
 The following is the manner of using the symbols: For the 
 compound consisting of hydrogen and oxygen in the ratio of 2 
 to 16, the chemical symbol is H,O, meaning 2 of hydrogen to 1 
 of oxygen. (This compound is water.) For the compound of 
 oxygen and magnesium just referred to, the symbol is MgO; 
 for the two compounds of oxygen and iron, FeO, protoxide of 
 iron; Fe,O,, sesquioxide of iron, the ratio of 1 to 1} being ex- 
 pressed by 2 to 3; for the two compounds of sulphur and oxy- 
 gen, SO, and SO. 
 
 Some of the elements so closely resemble one another that 
 their similar compounds are closely alike in erystallization and 
 other qualities, and they are therefore said to be zsomorphous. 
 
 This is true of iron, magnesium, calcium, and two or three 
 other related elements. In one group of compounds of these 
 bases, the carbonates, the crystalline form for each is rhombohe- 
 
78 CHEMICAL PROPERTIES OF MINERALS. 
 
 dral, and among them there is a difference of less than two de- 
 grees in the angle of the rhombohedron. Besides a carbonate 
 of calcium, a carbonate of magnesium, and a carbonate of iron, 
 there is also a carbonate of calcium and magnesium, in which 
 half of the calcium of the first of these carbonates is replaced 
 by half an atom of magnesium; and another species in which 
 the base, instead of being all magnesium, is half magnesium and 
 half iron. By half is here meant half in the proportion of their 
 combining weights. 
 
 The replacement of one of these elements by the other, and 
 similar replacements among Other groups of related elements, 
 run through the whole range of mineral compounds. Thus we 
 have sodium replacing potassium, arsente replacing phosphorus 
 and antimony, and so on. 
 
 In the combinations of oxygen and iron, as illustrated above, 
 oxygen is combined with the iron in different proportions. 
 FeO contains | of Fe (iron) to 1 of O (oxygen) and Fe,O;, or, as 
 it is often written, FeO,, contains 2 Fe to 1 of O. As the iron in 
 each of these cases satisfies the oxygen, it is evident that the 
 iron must be in two different states, (1) a protomide state, and 
 (2) a sesquiowide state. One part of iron in this sesquioxide 
 state (= 2 Fe) often replaces in compounds one part of iron in 
 the protoxide state (or 1Fe), with no greater change of quali- 
 ties than happens in the replacement of iron by magnesium, or 
 calcium, explained above; or, avoiding fractions, 3 parts of Fe 
 in the protoxide state replaces 2Fe in the sesquioxide state. 
 Writing Ee for the last 2Fe, the statement becomes 1 of Fe; 
 replaces 1 of Fe. Aluminium ‘occurs only in the sesqui- 
 oxide state, and the ordinary symbol of the oxide is Al,O:, 
 or AlO, But it is closely related to iron in the sesquioxide 
 state, so that, using the same mode of expression as for iron, 
 lof Al replaces 1 of Fe,, or 1 of Mg;, and so on. Similarly, 
 writing R for any metal, 1 of R replaces 1 of R, Again, in 
 potash (K,O), soda (Na,O), lithia (Li,O), water (H,O), one of 
 oxygen (O) is combined severally with 2 of K (potassium), of 
 Na (sodium), of Li (lithium), of hydrogen ; and hence 2K, 
 2Na, 2Li, that is, K,, Na,, Li,, may each replace in compounds 
 1Ca, or 1Mg, etc. 
 
 The elements potassium, sodium, lithium, hydrogen, of which 
 it takes two parts to combine with 1 of oxygen, are called 
 monads. Other elements of the group of monads are rubidium, 
 cesium, thallium, silver, and also fluorine, chlorine, bromine, 
 iodine. Still other elements combining by two parts in their 
 oxygen or sulphur compounds, etc., are nitrogen, phosphorus, 
 
CHEMICAL COMPOSITION OF MINERALS. 9 
 
 antimony, boron, columbium, tantalum, vanadium, gold. For 
 example, for arsenic there are the compounds As,S, As,S,, 
 As,O,, As,O;, etc. Another characteristic of these elements of 
 the hydrogen, sodium, chlorine, and arsenic groups is that the 
 number of equivalents of the acidic element in the compounds 
 into which they enter is, with a rare exception, odd, and of the 
 1, 3, 5, etce., series, and on this account they are called in 
 chemistry perissads ; while the other elements, in whose com- 
 pounds their number is of the l, 2, 3, etc. (or 2, 4, 6) series, 
 are called artiads. An apparent exception exists under the 
 artiads in the sesquioxides, but this does not alter the general 
 character of the series. 
 
 The facts above cited sustain the general statement that 
 Ca,, Mg,, Mn;, Zn, Fe,, Al, Ee, Mn, have equivalent combin- 
 ing values, and hence in minerals often replace one another 5 
 and so also Ca, Mg, Mn, Zn, Fe, K,, Nas, Li,, H., may replace 
 one another. Similarly, also, As,, or Sb, replaces 5 in some 
 minerals. 
 
 With reference to the classification of minerals the elements 
 may be conveniently divided into two groups: (1) the Acidic, 
 and (2) the Basic. The former includes oxygen and the ele- 
 ments which were termed the acidifiers and acidifiable elements 
 in the old chemistry. They are those which have been called 
 in mineralogy the mineralizing elements, since they are the 
 elements which are found combined with the metals to make 
 them ores, that is, to mineralize them. The basic are the rest 
 of the elements. The groups overlap somewhat, but this need 
 not be dwelt upon here. 
 
 The more important of the acidic elements are the following : 
 oxygen, fluorine, chlorine, bromine, iodine, sulphur, selenium, 
 tellurium, boron, chromium, molybdenum, tungsten, phosphorus, 
 arsenic, antimony, vanadium, nitrogen, tantalum, columbiun, 
 carbon, silicon. 
 
 Again, among the compounds of these elements occurring in 
 the mineral kingdom there are two grand divisions, the binary 
 and the ternary. ‘The binary consist of one or more elements 
 of each of the acidic and basic divisions, and the ternary of one 
 or more elements of each of these two classes, along with oxy- 
 gen, fluorine, or sulphur as a third. The binary include the 
 sulphides, arsenides, chlorides, fluorides, oxides, etc., and the 
 ternary the sulphates, chromates, borates, arsenates, phosphates, 
 silicates, carbonates, etc., and also the sulph-arsenites and sulph- 
 antimonites, in which a basic metal (usually lead, copper, sil- 
 ver) is combined with arsenic or antimony and sulphur. 
 
80 CHEMICAL PROPERTIES OF MINERALS. 
 
 The following are examples of the symbols of binary and 
 ternary compounds : 
 
 1. Binary. 
 
 1. Sulphides, Selenides.—Ag,S = silver sulphide; Ag,Se = 
 silver selenide; PbS = lead sulphide; ZnS = zine sulphide ; 
 FeS, = iron disulphide. 
 
 2. Fluorides, Chlorides, etec.—Ca¥, = calcium fluoride ; AgCl 
 = silver chloride; AgBr = silver bromide; AglI = silver 
 iodide ; NaCl = sodium chloride (common salt). 
 
 3. Oxides. — Al,O, = 3(A1,,0) = aluminium sesquioxide ; 
 As,O; = arsenic trioxide; As,O; = arsenic pentoxide; BaO = 
 barium oxide; B,O, = boron trioxide (boracic acid) ; CaO = 
 calcium oxide (lime) ; CO, = carbon dioxide (carbonic acid) ; 
 CrO, = chromium trioxide (chromic acid) ; Cu,O = copper sub- 
 oxide; CuO = copper oxide; BeO = beryllium oxide; H,O = 
 hydrogen oxide (water); FeO = iron oxide; Fe,O; = iron 
 sesquioxide ; PbO = lead oxide; Li,O = lithium oxide; MgO 
 — magnesium oxide; MnO = manganese oxide; Mn,O; = 
 manganese sesquioxide ; MnO, = manganese dioxide; P,O; = 
 phosphorus pentoxide; K,O = potassium oxide ; 810, = silicon 
 dioxide (silica); Na,O = sodium oxide; SrO = strontium ox- 
 ide; SO, = sulphur dioxide (sulphurous acid) ; SO; = sulphur 
 trioxide; SnO, = tin dioxide; V,O; = vanadium pentoxide 
 (vanadie acid); WO, = tungsten trioxide (tungstic acid) ; 
 ZnO = zinc oxide; ZrO, = zirconium dioxide. 
 
 The composition of these compounds may be obtained from 
 the table of combining weights, page 76. For example, with 
 reference to the first of them (AgS), the table gives for the 
 combining weight of silver (Ag), 108, and for that of sulphur, 32. 
 The elements exist in the compound therefore in the proportion 
 of 108 to 32, and from it the composition of a hundred parts is 
 easily deduced. 
 
 If the formula were (Ag, Pb)S, signifying a silver-and-lead 
 sulphide, and if the silver and lead were in the ratio of | to ], 
 then half the combining weight of silver is taken; that is, 54, 
 and half the atomic weight of lead, which is 103-5; and the 
 sum of these numbers, with 32 for the sulphur, expresses the 
 ratio of the three ingredients. 
 
 For Al,O, we find the combining weight of aluminium 27.4 ; 
 doubling this for Al, makes 54:8. Again, for oxygen, we find 
 16; and three times 16 is 48. 54-8 to 48 is therefore the ratio 
 
CHEMICAL COMPOSITION OF MINERALS. 81 
 
 of aluminium to the oxygen in A1,O,, from which the percent- 
 age proportion may be obtained. 
 
 2. Ternary Oxygen Compounds. 
 
 Silicates.—Of these compounds there are two prominent 
 groups. In one of these groups the general formula is RO;8i, 
 and in the other R,O,Si. In both of these formulas R stands 
 for any basic elements in the protoxide state, as Ca, Mg, Fe, 
 etc., either alone or in combination. In the first of these for- 
 mulas the combining values of the basic element R and. the 
 acidic element or silicon, as measured by their combinations 
 with oxygen, are in the proportion of 1 to 2, for R stands 
 for an element in the protoxide state, while Si stands for sili- 
 con, which is in the diowide state, its oxide being a dioxide ; 
 and hence the minerals so constituted are called Disilicates. In 
 the second of these formulas this ratio is 2 to 2, or 1 to 1, and 
 hence these are called Unisilicates. 
 
 Multiplying these formulas by 3, they become R,0O,8i;, and 
 (2R,) O,.8i;; and the same composition is expressed. In this 
 form the substitution of sesquioxide bases for protoxide may 
 be indicated: thus, R;R O,, 81, signifies that half of the 2R; is re- 
 placed by Al or Fe, or some other element in the sesquioxide 
 state. | 
 
 There are also some species in which the ratio is 1 to less 
 than 1, and these are called Subsilicates. 
 
 The ratio here referred to (formerly known as the oxygen 
 ratio) is called the quantwalent ratio. 
 
 The other ternary compounds require no special remarks in 
 this place. 
 
 2. CHEMICAL REACTIONS. 
 1. Trials in the wet way. 
 
 1. Zest for Carbonates.—Into a test tube put a little hydro- 
 chloric acid diluted with one half water, and add a small por- 
 tion in powder of the mineral. Ifa carbonate, there will be a 
 brisk effervescence caused by the escape of carbonic dioxide 
 (carbonic acid), when heat is applied, if not before. With cal- 
 cium carbonate no heat or pulverization is necessary. 
 
 2. Test for Gelatinizing Silica.—Some silicates, when pow- 
 
 6 
 
82 CHEMICAL PROPERTIES OF MINERALS. 
 
 dered and treated with strong hydrochloric acid, are decom- 
 posed and deposit the silica in a state of a jelly. The experi- 
 ment may be performed in a test tube, or small glass flask. 
 Sometimes the evaporation of the liquid nearly to dryness 1s 
 necessary in order to obtain the jelly. Some silicates do not 
 afford the jelly unless they have been previously ignited before . 
 the blowpipe, and some gelatinizing silicates lose the power on 
 ignition. 
 
 3. Decomposability of Minerals by Acids.—To ascertain . 
 whether a mineral is decomposable by acids or not, it is very 
 finely powdered and then boiled with strong hydrochloric acid, 
 or, in case of many metallic minerals, with nitric acid. In 
 some cases where no jelly is formed there 1s a deposit of silica 
 in fine flakes. With the sulphides and nitric acid there is often 
 a deposit of sulphur, which usually floats upon the surface of 
 the fluid as a dark spongy mass. Some oxides, and also some 
 sulphates and many phosphates, are soluble entirely without 
 effervescence. But many minerals resist decomposition. It is 
 sometimes difficult to tell whether a mineral is decomposed with 
 the separation of the silica or whether it is unacted upon. In 
 such a case a portion of the clear fluid is neutralized by soda 
 (sodium carbonate), and if anything has been dissolved it will 
 usually be precipitated. 
 
 Test for F'luorine.—Most fluorides are decomposed by strong 
 heated sulphuric acid, give out fluorine which will etch a glass 
 plate in reach of the fumes. The trial may be made in a lead 
 cup and the glass put over it as a loose cover. 
 
 2. Trials with the Blowprpe. 
 
 The blowpipe, in its simplest form, is merely a bent tube of 
 small size, eight to ten inches long, terminating at one end in a 
 minute orifice. It is used to concentrate the flame on a min- 
 eral, and this is done by blowing through it while the smaller 
 end is just within the flame. 
 
 The annexed figure represents the form commonly employed, 
 except that the tube is usually without the division at 0. It 
 contains an air chamber (0) to receive the moisture which is 
 condensed in the tube during the blowing; the moisture, unless 
 thus removed, is often blown through the small aperture and 
 interferes with the experiment. The jet, ¢/, 1s movable, and 
 ++ ig desirable that it should be made of platinum, in order that 
 it may be cleaned when necessary, either by high heating or 
 
CHEMICAL COMPOSITION OF MINERALS, 83 
 
 by immersion in an acid. The screw at 0 is for the purpose of 
 shortening the tube one-half so as to make it more convenient 
 for the pocket of the field mineralogist. It is un- 
 screwed for this purpose, and the smaller part put 
 within the larger. 
 
 In using the blowpipe it is necessary to breathe 
 and blow at the same time, that the operator may 
 not interrupt the flame in order to take breath. 
 Though seemingly absurd, the necessary tact may 
 easily be acquired. Let the student first breathe a 
 few times through his nostrils while his cheeks are 
 inflated and his mouth closed. After this practice 
 let him put the blowpipe to his mouth and he will 
 find no difficulty in breathing as before while the 
 muscles of the inflated cheeks are throwing the air 
 they contain through the blowpipe. When the air 
 is nearly exhausted the mouth may again be filled 
 through the nose without interrupting the process 
 _ of blowing. 
 
 The flame of a candle, or-a lamp with a large lL is 
 wick may be used, and when so it should be bent 
 in the direction the flame is to be blown. But it is far better, 
 when gas can be had, to use a Bunsen’s burner. 
 
 The flame has the form of a cone, yellow without and blue 
 within. The heat is most intense just beyond the extremity of 
 the blue flame. In some trials it is necessary that the air 
 should not be excluded from the mineral during the experiment, 
 and when this is the case the owter flame is used. ‘The outer is 
 called the oxidizing flame (because oxygen, one of the consti- 
 tuents of the atmosphere, combines in many cases with some 
 parts of the assay, or substance under experiment), and the in- 
 ner the reducing flame. In the latter the carbon and hydrogen 
 of the flame, which are in a high state of ignition, and which are 
 enclosed from the atmosphere by the outer flame, tend to unite 
 with the oxygen of any substance that is inserted init. Hence 
 substances are reduced in it. 
 
 The mineral is supported in the flame either on charcoal; or 
 by means of steel forceps (as in the annexed figure) with plati- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 num extremities (a 6), opened by pressing on the pins p p; or 
 on platinum wire or foil. 
 
84 CHEMICAL PROPERTIES OF MINERALS. 
 
 To ascertain.the fusibility of a mineral, the fragment for the 
 platinum forceps should not be larger than the head of a pin, 
 and, if possible, should be thin and oblong, so that the extrem- 
 ity may project beyond the platinum. The fusible metals alloy 
 readily with platinum. Hence compounds of lead, arsenic, an- 
 timony, etc., must be guarded against. These compounds are 
 tested on charcoal. The forceps should not be used with the 
 fluxes, but instead either charcoal or the platinum wire or foil. 
 
 The charcoal should be firm and well burnt; that of soft 
 wood is the best. It is employed especially for the reduction 
 of oxides, in which the presence of carbon is often necessary, 
 and also for observing any substances which may pass off and 
 be deposited on the charcoal around the assay. These coatings 
 are usually oxides of the metals, which are formed by the oxi- 
 dation of the volatile metals as they issue from the reduction 
 flame. 
 
 The platinum wire is employed in order to observe the ac- 
 tion of the fluxes on the mineral, and the colors which the 
 oxides impart to the fluxes when dissolved in them. The wire 
 used is No. 27. This is cut into pieces about three inches long, 
 and the end is bent into a small loop, in which the flux is fused. 
 This makes what is called a bead.’ When the experiment is 
 complete the beads are removed by uncoiling the loop and draw- 
 ing the wire through the finger nails. After use for awhile the 
 end breaks off, because platinum is acted upon by the soda, and 
 then a new loop has to be made. Dilute sulphuric acid will 
 remove any of the flux that may remain upon it after a trial 
 has been made. 
 
 Glass tube is employed for various purposes. It should be 
 from a line to a fourth of an inch in bore. It is cut into pieces 
 four to six inches long, and used in some cases with both ends 
 open, in others with one end closed. In the closed tube, either 
 heated directly over the Bunsen burner, or with the aid of the 
 blowpipe, volatile substances in the assay are vaporized and 
 condensed in the upper colder part of the tube, where they 
 may be examined by a lens if necessary, or by further heating. 
 The odor given off may also be noted, and the acidity of any 
 fumes by inserting a small strip of litmus paper in the mouth 
 of the tube. ‘Lhe closed tube is used to observe all the effects 
 that may take place when a substance is heated out of contact 
 with the air. In the open tube the atmosphere passes through 
 the tube in the heating, and so modifies the result. ‘The assay 
 is placed an inch or an inch and a quarter from the lower end 
 of the tube; tbe tube should be held nearly horizontally, to 
 
BLOWPIPE REACTIONS. 85 
 
 prevent the assay from falling out. The strength of the 
 draught depends upon the inclination of the tube, and in special 
 cases it should be inclined as much as possible. 
 
 The most common fluxes are borax (sodium bi-borate), salt 
 of phosphorus (sodium and ammonium phosphate), and soda 
 (sodium carbonate, either the carbonate or bi-carbonate of soda 
 of the shops.) These substances, when fused and highly heated, 
 are very powerful solvents for metallic oxides. They should 
 be pure preparations. The borax and soda are much the most 
 important. In using the platinum wire, the loop may be highly 
 heated, and then a portion of the borax or soda may be taken 
 up by it, and by successive repetitions of this process the re- 
 quisite amount of the flux may be obtained on the wire. Then, 
 by bringing the melted flux of the loop into contact with one 
 or more grains of the pulverized mineral, the assay is madt 
 ready for the trial. With soda and quartz a perfectly clear 
 globule is obtained, cold as well as hot, if the flux is used in 
 the right proportion. Some oxides impart a deep and charac- 
 teristic color to a bead of borax. In other cases the color 
 obtained is more characteristic when salt of phosphorus is em- 
 ployed. The color obtained in the outer flame 1s often differ- 
 ent from that which is obtained in the inner flame. The beads 
 are sometimes transparent and sometimes opaque. If too much 
 substance is employed the beads will be opaque when it is de- 
 sired that they should be transparent. In such cases the 
 experiment may be repeated with less substance. In many 
 cases pulverized mineral and the flux, a little moistened, are 
 mixed together into a ball upon charcoal, especially in the ex- 
 periments with soda. 
 
 In the examination of sulphides, arsenides, antimonides and 
 rélated ores, the assay should be roasted before using a flux, in 
 order to convert the substance into an oxide. This is done by 
 spreading the substance out on a piece of charcoal and exposing 
 it to a gentle heat in the oxidizing flame. The sulphur, arsenic, 
 antimony, etc., then pass off as oxides in the form of vapors, 
 leaving the non-volatile metals behind as oxides. The escap- 
 ing sulphurous acid gives the ordinary odor of burning sulphur 5 
 arsenous acid, from arsenic present, the odor of garlic, or an 
 - alliaceous odor; selenous acid, from selenium present, the odor 
 of decaying horse-radish ; while antimony fumes are dense white, 
 and have no odor. 
 
 The following is the scale of fusibility which has been adopted, 
 beginning with the most fusible : 
 
 1. Stisnrte.—Fusible in large pieces in the candle flame. 
 
86 CHEMICAL PROPERTIES OF MINERALS. 
 
 9. Narroxite.—Fusible in small splinters in the candle 
 flame. 
 
 3. ALMANDINE, or bright red GARNET.—Fusible in large 
 pieces with ease in the blowpipe flame. 
 
 4. ActTINOLITE.—Fusible in large pieces with difficulty in the 
 blowpipe flame. 
 
 5. ORTHOCLASE, or common feldspar. Fusible in small 
 splinters with difficulty in the blowpipe flame. 
 
 6. Bronzite.—Scarcely fusible at all. 
 
 The color of the flame is an important character in connection 
 with blowpipe trials. When the mineral contains sodiwm the 
 color of the flame is deep yellow, and this is generally true in 
 spite of the presence of other related elements. When sodium 
 (or soda) is absent, potassium (or potash) gives a pale violet 
 color; calciwm (or lime) a pale reddish yellow ; lithium, a deep 
 purple-red, as: in lithia-mica ; strontiwm, a bright red, this ele- 
 ment being the usual source of the red color in pyrotechny ; 
 copper, emerald green ; phosphates, bluish green ; boron, yellow- 
 ish green ; copper chloride, azure blue. Beads should be exam- 
 ined by daylight only, and should be held in such position that 
 the color is not modified by green trees or other bright objects 
 when examined by transmitted light. Colored flames are seen 
 to best advantage when some black object is beyond the flame 
 in the line of vision. 
 
 It is also to be noted, in the trials, whether the assay heats 
 up quietly, or with decrepitation ; whether it fuses with effer- 
 vescence or not, or with intumescence or not; whether it fuses 
 to a bead which is transparent, clouded, or opaque; whether 
 blebby (containing air-bubbles or not); whether scoria-like or 
 not. 
 Testing for Water.—The powdered mineral is put at the 
 bottom of a closed glass tube, and after holding the extremity 
 for a moment in the flame of a Bunsen’s burner, moisture, if 
 any is present, will have escaped and be found condensed on the 
 inside of the tube, above the heated portion. Litmus or tur- 
 meric paper is used to ascertain if the water is acid or alkaline, 
 acids changing the blue of litmus paper to red, and alkalies the 
 yellow of turmeric paper to brown. 
 
 Testing for an Alkali.—If the fragment of a mineral, heated 
 in the platinum forceps, contains an alkali, it will often, after 
 being highly heated, give an alkaline reaction when placed, 
 after moistening, on turmeric paper, turning it brown. ‘This 
 test is applicable to those salts which, on heating, part with a 
 portion of their acid and are rendered caustic thereby. Such 
 
BLOWPIPE REACTIONS. ' 87 
 
 are the carbonates, sulphates, nitrates, and chlorides of the 
 alkaline metals. 
 
 Testing for Alumina or Magnesia,—Cobalt nitrate, in solu- 
 tion, is used to distinguish an infusible and colorless mineral 
 containing aluminium from one containing magnesium. <A 
 fragment of the mineral is first ignited, and then wet with a 
 drop or two of the cobalt solution and heated again. The alu- 
 minium mineral will assume a blue color, and the magnesium 
 mineral a pale red or pink. 
 
 Any fusible silicate, when moistened with cobalt nitrate and 
 ignited will assume a blue color, hence this test is only deci- 
 sive in testing infusible substances. 
 
 Infusible zinc compounds, when moistened with cobalt nitrate, 
 assume a green color. 
 
 Testing for Lithium.—Some lithium minerals give the 
 bright purple-red flame if simply heated in the platinum for- 
 ceps. In other cases mix the powdered mineral with one part 
 of fluorite and one of potassium bi-sulphate. Make the whole 
 into a paste with a little water, and heat it on the platinum 
 wire in the blue flame. 
 
 Testing for Boron.—When the bright yellow-green of boron 
 is not obtained directly on heating the mineral containing it, 
 one part of the powdered mineral should be mixed with one 
 part of powdered fluorite and three of potassium bi-sulphate ;_ 
 and then treated as in the last. The green color appears at the 
 instant of fusion. 
 
 Testing for Fluorine.—To detect fluorine in fluorides mix a 
 little of the powdered substance with potassium bi-sulphate, 
 put the mixture in a closed glass tube and fuse gently. The 
 bi-sulphate gives off half of its sulphuric acid at a high temper- 
 ature, which acts powerfully on anything it can attack. Ifa 
 fluoride is present, hydrofluoric acid will be given off, and the 
 walls of the tube will be found roughened and etched when the 
 tube is broken open and cleaned after the experiment. Ifa 
 silicate containing fluorine be powdered and mixed with previ- 
 ously fused salt of phosphorus, and heated in the open tube by 
 blowing the flame into the lower end of the tube, hydrofluoric 
 acid is given off, and the tube 1s corroded just above the assay. 
 
 Silicates.—Nearly all silicates undergo decomposition with 
 salt of phosphorus, setting free the silica, forming a bead which 
 ss clear while hot and hasa skeleton of silica floating in it. 
 The bead is sometimes clear also when cold. 
 
 Tron.—Minerals containing much iron produce a magnetic 
 globule when highly heated. Usually the reducing flame is 
 
88 CHEMICAL PROPERTIES OF MINERALS. 
 
 required, and sometimes the use of soda. With borax iron 
 gives a bead with the oxidizing flame which is yellow while 
 hot, but colorless on cooling, and which in the reducing flame 
 becomes bottle green. 
 
 Cobalt.—Minerals containing cobalt afford, with borax, a 
 beautiful blue bead. If sulphur or arsenic is present it should 
 be first roasted off on charcoal. 
 
 Nickel.—In the oxidizing flame with borax, the bead is violet 
 when hot, and red-brown on cooling. In the reducing flame 
 the glass becomes gray and turbid from the separation of metal- 
 lic nickel, and on long blowing, colorless. The reaction 1s ob- 
 scured by the presence of cobalt, iron, and copper. 
 
 Manganese.—With borax in the oxidizing flame, the bead is 
 a deep violet-red, and almost black if too much of the mineral 
 ig used. To see the color examine by transmitted light. With 
 soda in the same flame the opaque bead is bluish green. 
 
 Chromium.—With borax, both in the oxidizing and reducing 
 flame, the bead is bright emerald green. 
 
 Titanium.—Titanium oxide with salt of phosphorus on 
 platinum wire in O.F. dissolves to a clear glass, which, if 
 much is present, becomes yellow while hot and colorless on 
 cooling; but in R.F. the hot globule obtained in O.F. reddens 
 and assumes finally a beautiful violet color. On charcoal with 
 tin the glass becomes violet if there is not too much iron 
 present. 
 
 Zine.—Zine and some of its compounds when heated cover 
 the charcoal with zine oxide, which is yellow while hot, but 
 white on cooling ; and this coating, if wet with cobalt solution 
 and then heated, assumes a fine yellowish-green color which 
 is most distinct when cold. 
 
 Lead, copper, tin, silver, when characterizing a mineral, give 
 with soda in the reducing flame minute metallic globules, which 
 are malleable, or may be cut with a knife; they can be distin- 
 guished by their well-known physical properties. When two 
 or more of these metals occur together, or iron is also present, 
 the globules consist usually of an alloy of the metals. 
 
 Lead.—When the mineral is treated with soda on charcoal 
 in the oxidizing flame, the yellow oxide coats the charcoal 
 around the assay. 
 
 Copper.—The flame is colored, in most cases, bright green. 
 With borax or salt of phosphorus in the reducing flame the 
 bead is red. In the oxidizing flame the bead is green when 
 hot and becomes blue or greenish blue on cooling. 
 
 Mercury.—Heated in the closed tube with soda, a sublimate 
 of metallic mercury covers the inside of the tube. 
 
BLOWPIPE REACTIONS. 89 
 
 Silver.—lIf the silver is in very small quantities, as in argen- 
 tiferous galena, the assay is put into a little cup made of bone 
 ashes (bone burnt white and finely pulverized), and subjected 
 to the oxidizing flame ; the lead is oxidized and sinks into the 
 bone ashes, leaving the silver a brilliant globule on the cupel. 
 Before cupellation it is often necessary to melt the assay to- 
 gether with some borax and pure lead in a hole on charcoal. 
 By this process the sand and impurities are removed, and a 
 globule of lead is obtained which contains all the silver, and 
 which may be separated from the slag and be oxidized as 
 above. 
 
 Arsenic.—In the closed tube arsenic sublimes and coats the 
 tube with brilliant grains, or a crust, of metallic arsenic. If 
 the mineral contains sulphur as well as arsenic, sublimates of 
 the yellow and red arsenic sulphides (orpiment and realgar) are 
 often formed. In the open tube a sublimate of white arsenous 
 acid is formed, which condenses in bright crystals on the walls 
 of the tube, and a strong garlic odor is given off. On charcoal 
 the alliaceous odor is at once perceptible. 
 
 Antimony.—In the closed tube, when sulphur is present, the 
 assay yields a sublimate which is black when hot, brown-red 
 when cold. In the open tube dense white vapors are given off 
 and a white amorphous sublimate covers the inside of the tube, 
 which, for the most part, does not volatilize when reheated. 
 On charcoal the assay yields dense, white, inodorous fumes. 
 
 Tellurium.—In the open tube a white or grayish sublimate 
 is obtained, which may be fused to clear, colorless drops. On 
 charcoal a white coating is produced, and the reducing flame is 
 colored green. 
 
 Sulphur.—All sulphates, and other sulphur-bearing miner- 
 als, when heated on charcoal with soda, produce a dark, yellow- 
 ish brown sulphide of sodium; and if a fragment of this is 
 moistened and placed on a polished plate of silver, it turns it 
 immediately brownish black, or black. Pure soda, and a flame 
 wholly free from sulphur, is needed for the trial, since the least 
 trace of sulphur in either vitiates the result. Many sulphides 
 give fumes of sulphur on charcoal. The higher sulphides afford 
 these fumes in a closed tube. The others afford fumes of sul- 
 phurous acid in an open tube, which redden a moistened blue 
 litmus paper placed in the upper end of the tube. 
 
 Selenitum.—Selenium and many selenides afford a steel-gray 
 sublimate in an open tube, which at the upper edge appears 
 red. On charcoal brown fumes are given off with an odor like 
 that of decaying horse-radish, 
 
90 CHEMICAL PROPERTIES OF MINERALS. 
 
 Ohlorides.—If a bead of borax be saturated with copper 
 oxide, and then dipped into the powder of a substance which is 
 to be tested for chlorine, a chloride of copper is formed which 
 imparts an azure blue color to the flame if any chlorine is pres- 
 ent. If dissolved in water or nitric acid a little silver nitrate 
 produces a dense white precipitate of silver chloride. 
 
 Nitrates. —A nitrate, if fused on charcoal, will deflagrate with 
 brilliancy, owing to the decomposition of the nitrate and the 
 union of its oxygen with the carbon. 
 
 Phosphates.-—Phosphates give a dirty green color to the blow- 
 pipe flame. The color ig more distinct if the substance is first 
 moistened with sulphuric acid. If a phosphate 1s pulverized 
 and heated in a closed glass tube with some bits of magnesium 
 wire, the phosphoric acid is reduced, and when the fusion is 
 moistened with water the very disagreeable odor of phosphuretted 
 hydrogen is obtained. 
 
 For a fall account of blowpipe reactions recourse must be 
 had to 2 treatise on the blowpipe. The best and fullest Ameri- 
 can work on the subject is Prof. G. J. Brush’s “ Manual of De- 
 terminative Mineralogy, with an Introduction on Blowpipe 
 Analysis.” 
 
 In this work the following abbreviations are used in speaking 
 of blowpipe reactions : 
 
 B.B. = before the blowpipe; OF. = oxidizing flame ; 
 RF. = reducing flame. 
 
CLASSIFICATION, 91 
 
 4. DESCRIPTIONS OF MINERALS. 
 
 CLASSIFICATION. 
 
 Somn of the prominent points in the classification of minerals 
 adopted in the following pages are given in connection with the 
 remarks on chemical composition, pages 79. 
 
 Many instructors in the science, and most of those who con- 
 sult a work on Mineralogy for practical purposes, prefer an ar- 
 rangement of the ores which groups them under the head of the 
 metal prominent in their constitution. The method of group- 
 ing mineral species according to the basic element has therefore 
 been here, to a large extent, followed. An exception has been 
 made in the case of the silicates, because it is witb them almost 
 impracticable, on account of the number of basic elements they 
 often contain ; and, moreover, not more than half a dozen use- 
 ful ores exist among them. ‘The silicates therefore, which in- 
 clude the larger part of all minerals, make together one of the 
 grand divisions in the classification, and they are presented ac- 
 cording to their natural groups, in the same order as in the 
 larger mineralogy. 
 
 The prominent subdivisions in the classification are as fol- 
 lows: 
 
 I. Tur Acrpic pivision, including the acidic elements oc- 
 curring native, and the native compounds of the acidic elements 
 with one another. 
 
 II. Tue Basic Division, including the basic elements occur- 
 ring native, and the native binary and ternary compounds of 
 the basic elements—the silicates excepted. 
 
 III. Srzica and the SILIcATEs. 
 
 TV. THe Hyprocarson Compounps, including mineral oils, 
 resins, wax, and coals. 
 
 The following are the chief subdivisions under these heads: 
 
 I. Acirpic DIvIsIon. 
 
 1. Sulphur Group.—The chief oxide a trioxide, its formula 
 RO,. Includes Sulphur and sulphur oxides; Tellurium and 
 tellurium oxides ; Molybdenum sulphide and oxide ; Tungsten 
 oxide. 
 
92 DESCRIPTIONS OF MINERALS. 
 
 2. Boron Group.—The chief oxide a trioxide, its formula 
 R,O, Includes compounds of Boron with oxygen. 
 
 3. Argenic Group.—The chief oxide a pentoxide, its formula 
 R,O;. Includes Arsenic and arsenic sulphides and oxides ; An- 
 timony and antimony sulphide, arsenide and oxides; Bismuth 
 and bismuth sulphide, telluride and oxide. 
 
 4. Carbon Group.—The chief oxide a dioxide, its formula 
 RO,. Includes Carbon (Diamond, Graphite) and carbon diox- 
 ide. ,(Quartz, Si O,, belongs here chemically, but 1s placed with 
 the Silicates. ) 
 
 II. Basic Division. 
 
 Gold ; Silver; Platinum and Iridium; Palladium; Quick- 
 silver ; Copper ; Lead ; Zinc; Cadmium ; Tin; Titanium ; Co- 
 balt and Nickel; Uranium ; Iron; Manganese; Aluminium ; 
 Cerium, Yttrium, Lanthanum, Didymium and Erbium; Mag- 
 nesium; Calcium; Barium and Strontium; Potassium and 
 Sodium; Ammonium ; Hydrogen. 
 
 III. SrxuicA AND SILICATES. 
 
 1. Silica. 
 2. Anhydrous Silicates. 
 1. Bisilicates. 
 2. Unisilicates. 
 3. Subsilicates. 
 3. Hydrous Silicates. 
 1. General section of Hydrous Silicates.. 
 2. Geolite section. 
 3. Margarophyllite section. 
 
 IV. HyprocArBon COMPOUNDS. 
 
 Oils, Resins, Wax. : 
 Asphaltum, Coals. 
 
 Se a 
 
 GENERAL REMARKS ON ORES. 
 
 An ore, in the mineralogical sense of the word, is a mineral 
 compound in which a metal isa prominent constituent. In the 
 
GENERAL REMARKS ON ORES. 93 
 
 miner’s use of the term it is a mineral substance that yields, by 
 metallurgical treatment, a valuable metal, and especially when 
 it profitably yields such a metal. In the former sense, galena, 
 the common cre of lead, is, if it contains a little silver, an 
 argentiferous lead-ore; while, in the latter, if there is silver 
 enough to make its extraction profitable, it is a silver-ore. 
 Further than this, where a native metal, or other valuable 
 metallic mineral, is distributed intimately through the gangue, 
 the mineral and gangue together are often called the ore of the 
 metal it produces. 
 
 We have beyond to do with ores only in the mineralogical 
 sense. 
 
 Ores are compounds of the metals, not metals in the native 
 state. The more common kinds are compounds of the metals 
 with Sulphur (sulphides) ; with Arsenic (arsenides) ; with Sul- 
 phur and Arsenic (sulph-arsenides) ; with sulphur in ternary 
 combination along with arsenic, antimony or bismuth (making 
 compounds called sulph-arsenites, sulph-antimonites, sulpho-bis- 
 mutites); with Selenium (selenides); with Zellurium (tellu- 
 rides) ; with Oxygen (oxides); with Chlorine, Jodine, or Bro- 
 mine (chlorides, iodides, or bromides) ; with oxygen in ternary 
 combination with carbon (making carbonates) ; with Sulphur 
 (making sulphates); with Arsenic (making arsenates) ; with 
 Phosphorus (making phosphates); with Silicon (making sili- 
 cates). 
 
 Gold and platinum are, with rare exceptions, found only na- 
 tive, or intimately mixed in essentially the pure state with some 
 metallic minerals. Tellurium is the only acidic element that 
 occurs combined with gold in nature. 4 
 
 Suver is found in the state of sulphide, antimonide, selenide, 
 telluride, sulph-arsenites and sulph-antimonites, but never as 
 oxide or in oxygen ternary compounds. 
 
 Quicksilver occurs in the state of sulphide (the common ore) ; 
 also in that of selenide and sulph-arsenites. 
 
 Copper and lead occur in the state of sulphides (common ores), 
 and also in all the binary and ternary states mentioned above. 
 
 Zine is known in the state of sulphide (very common), 
 oxide, carbonate, sulphate, silicate (all, excepting the sulphate, 
 valuable as ores); and Cadmium in that of sulphide only. 
 
 7in occurs in the state of oxide (the common ore), and sul- 
 phide. 
 
 Cobalt and Nickel occur in the states of sulphide, arsenide, 
 sulph-arsenides, antimonide, oxide, sulphate, arsenate, carbon- 
 ate ; and nickel in that also of a silicate. 
 
94 DESCRIPTIONS OF MINERALS. 
 
 Tron oceurs in the state of sulphide (very common, but not 
 useful as an ore of iron), of arsenide, sulph-arsenide, oxide (the 
 common ores of iron), carbonate (useful ore), sulphate, arsen- 
 ate, phosphate, silicate. 
 
 Manganese occurs in the state of sulphide (rare), arsenide 
 (rare), oxide (the common ores), carbonate, sulphate, phosphate, 
 silicate. 
 
 
 
 I. MINERALS CONSISTING OF THE ACIDIC 
 . ELEMENTS. 
 
 Oxygen might properly be included in this section, since it 
 occurs native in the atmosphere mixed with nitrogen, consti- 
 tuting 21 per cent. of it. But this mention of it is all that is 
 necessary. The ternary compounds, in which, as in sulphuric 
 acid, hydrogen is the basic element, are here included. Chlor- 
 ine, bromine, and iodine do not occur native, and neither do their 
 oxides, nor any compounds with acidic elements, and hence these 
 elements are not represented under this division. The same is 
 true of selenium and chromium of the sulphur group, and of 
 yanadium, tantalum, and columbium of the arsenic group. 
 
 I. SULPHUR GROUP. 
 Native Sulphur. 
 
 Trimetric.—In acute octahedrons, and secondaries to this 
 form, with imperfect octahedral cleavage. 1A1 (in same pyra- 
 
 
 
 mid) = 106° 25’ and 85° 07’; 1A1 (over base) = 143° 23°. 
 Also massive. 
 Color and streak sulphur-yellow, sometimes orange-yellow. 
 
SULPHUR. 95 
 
 Lustre resinous. Transparent to translucent. Brittle. H.= 
 15—2°5. G.= 2.07. Burns with a blue flame and sulphurous 
 odor. Ina closed tube it is wholly volatilized and redeposited 
 on the wall of the tube. 
 
 Native sulphur is either pure, or contaminated with clay or 
 bitumen. It sometimes contains selenium, and has then an 
 orange-yellow color. 
 
 Diff. It is easily distinguished by its burning with a blue 
 flame, and the sulphur odor then afforded. 
 
 Obs. The great repositories of sulphur are either beds of 
 gypsum and the associate rocks, or the regions of active or ex- 
 tinct volcanoes. In the valley of Noto and Mazzaro in Sicily, 
 at Conil near Cadiz in Spain, Bex in Switzerland, and Cracow 
 in Poland, it occurs in the former situation. Sicily and the 
 neighboring volcanic islands, Vesuvius and the Solfatara in its 
 vicinity, Iceland, Teneriffe, Java, Hawaii, New Zealand, De- 
 ception Island, and most active volcanic regions afford more or 
 less sulphur. The native sulphur of commerce is brought 
 largely from Sicily, where it occurs in beds along the central 
 part of the south coast and to some distance inland. It under- 
 goes rough purification by fusion before exportation, which 
 separates the earth and clay with which it occurs. 
 
 On the Potomac, twenty-five miles above Washington, sul- 
 _phur has been found associated with calcite in a gray com- 
 pact limestone; sparingly about springs where hydrogen sul- 
 phide is evolved, in New York and elsewhere ; in cavities where 
 iron sulphides have decomposed, and in many coal mines; near 
 Borax Lake, in California; Inferno, Humboldt County, Nevada, 
 abundant. 
 
 The sulphur of commerce is also largely obtained from copper 
 and iron pyrites, it being given off during the roasting of these 
 ores. 
 
 Sulphur when cooled from fusion, or above 232° F., crys- 
 tallizes in oblique rhombic prisms. When poured into water 
 at a temperature above 300° F. it acquires the consistency of 
 soft wax, and is used to take impressions of gems, medals, etc., 
 which harden as the sulphur cools. The uses of sulphur for 
 gunpowder, bleaching, the manufacture of sulphuric acid, and 
 also in medicines, are well known. Sulphur occurs in various 
 ores as sulphides and sulphates. Among the sulphides are 
 pyrite, an iron sulphide; pyrrhotite, another iron sulphide ; 
 galena, a lead sulphide, the common ore of lead; chalcopyrite, 
 or yellow copper ore, a copper and iron sulphide; comnabar, a 
 mercury sulphide ; argentite, a silver sulphide, ete. 
 
96 DESCRIPTIONS OF MINERALS. 
 
 Sulphuric and Sulphurous Acids. 
 
 Sulphuric acid is occasionally met with around volcanoes, 
 and it is also formed from the decomposition of hydrogen 
 - sulphide about sulphur springs. 
 
 It is intensely acid. Composition, Sulphur teroxide (SO,) 
 81°6, water 18'4=100, it being chemically hydrogen sul- 
 phate. Occurs in the waters of Rio Vinagre, South America ; 
 also in Java, and at Lake de Taal on Luzon, in the East 
 Indies ; in Genesee Co., N. Y.; and at Tuscarora, St. Davids, 
 and elsewhere, Canada West. 
 
 Sulphurous acid, or sulphur dioxide (SO,), 1s produced 
 when sulphur burns, and causes the odor perceived during 
 the combustion. It is common about active volcanoes. It 
 destroys life and extinguishes combustion. Composition, 
 Sulphur 50°00, oxygen 50°00. 
 
 Native Tellurium. 
 
 Hexagonal; RAR = 86° 57. Occurs sometimes in 
 six-sided prisms with perfect lateral cleavage; but is com- 
 monly granular massive. Color and streak tin-white. Brit- 
 tie. inh. 2238: G.=6:'1-6°3. 
 
 Sometimes contains a little iron, and also a trace of gold. 
 In an open tube, B.B. yields a white inodorous sublimate, 
 which may be fused to colorless transparent drops ; and on 
 charcoal fuses and volatilizes, tinging the flame green, and 
 covering the charcoal with white tellurium dioxide. 
 
 Obs. Occurs in Hungary and Transylvania ; also, Boulder 
 Co., Colorado, at the Red Cloud Mine ; in Magnolia District 
 at the Keystone, Dun River, and other mines; in the Bal- 
 lerat District at Smuggler Mine; in Central District at the 
 John Jay Mine, where masses of 25 pounds weight are re- 
 ported to have been found. 
 
 Tellurium is also a constituent of ores of silver and lead (pp. 118, 149), 
 and these are the chief sources of the metal. . 
 
 Tellurite or Tellurous acid, TeO,, occurs at the Keystone, Smug- 
 gler, and John Jay Mines ; especially the last, where it is in minute 
 white or yellowish crystals having one eminent cleavage. 
 
 Molybdenite.—Molybdenum Sulphide. 
 
 ( 
 
 Hexagonal. In hexagonal plates, or masses, thin foliated, 
 like graphite, and resembling that mineral, H.= 1-10. 
 G.= 4:-45-4'8. Color pure lead-gray; streak the same, 
 
BORON GROUP. 97 
 
 slightly inclined to green. Thin lamine very flexible ; not 
 elastic; leaves a trace on paper, like graphite, but its color 
 is slightly different, being bluish-gray. 
 
 Composition. MoS,=Sulphur 41:0, molybdenum 59:0= 
 100. B.B. infusible, but when heated on charcoal, sulphur 
 fumes are given off, which are deposited on the coal. Dis- 
 solves in nitric acid, excepting a gray residue. 
 
 Diff. Resembles graphite, but differs in its paler color 
 and streak, and also in giving fumes of sulphur when heated, 
 as well as by its solubility in nitric acid. 
 
 Ods. Occurs in granite, gneiss, mica schist, and allied 
 rocks ; also in granular limestone. It is found in Sweden, 
 at Arendal in Norway, in Saxony, Bohemia, at Caldbeck 
 Fell in Cumberland, and in the Cornish mines. 
 
 In the United States it occurs in Maine at Blue Hill Bay, 
 Camdage Farm, Brunswick, and Bowdoinham; in New 
 Hampshire at Westmoreland, Landaff, and Franconia; in 
 Massachusetts at Shutesbury and Brimfield ; in Connecticut 
 at Haddam and Saybrook ; in New York near Warwick; in 
 New Jersey near the Franklin Furnace. 
 
 Molybdenum does*not occur native. An oxide is occa- 
 sionally found in yellow incrustations on molybdenite, as a 
 result of its alteration. It occurs, combined with lead, as a 
 molybdate (page 151), and this is the only native salt con- 
 taining it. The name molybdenum is from the Greek mo- 
 lubdaina, meaning mass of lead, and alludes to the resem- 
 blance of molybdenite to graphite. 
 
 TUNGSTITE, or Tungstic ochre. A yellow powder or incrustation oc- 
 curring with wolfram, and a result of its decomposition. Occasionally 
 observed at Lane’s Mine, Monroe, Conn. 
 
 Besides this oxide there are the native compounds, iron tungstate 
 or wolfram (p. 183), lead tungstate (p. 151), and calcium tungstate. 
 Tungsten also occurs sparingly in some ores of columbium, as in cer- 
 tain varieties of the minerals pyrochlore, columbite, and yttro-colum- 
 bite. 
 
 - II. BORON GROUP. 
 
 In Boron, as in the Sulphur group, the most prominent 
 oxide 1s a teroxide. 
 
 Sassolite.—Boracic Acid. Sassolin. 
 
 Occurs insmall scales, white or yellowish. Feel smooth and 
 
 unctuous. ‘Taste acidulous and a little saline pie bitter. 
 
98 DESCRIPTIONS OF MINERALS. 
 
 G.=1:48. Composition, H,O,Bo, = Boron teroxide 56:4, 
 water 43°6. It is strictly hydrogen borate. Fuses easily 
 in the flame of a candle, tinging the flame at first green. 
 
 Found at the crater of Vulcano, and also at Sasso in Italy, 
 whence it was called Sassolin. The hot vapors of the la- 
 goons of Tuscany afford it in large quantities. ‘The vapors 
 are made to pass through water, which condenses them ; and 
 the water is then evaporated by the steam of the springs, 
 and boracic acid obtained in large crystalline flakes. It 
 still requires purification, as the best thus procured contains 
 but 50 per cent. of the pure acid. Occurs also in the waters 
 of Lick Springs, Tehama Co., and Borax Lake, Lake Co., 
 California, where it was first observed, through their evapo- 
 ration, by Dr. J. A. Veatch, in 1856. It has since been 
 obtained from the waters of Mono, Owens, and other lakes. 
 It exists sparingly in the waters of the ocean. But in all 
 these waters, it is probably in combination. 
 
 Boron occurs usually in the condition of magnesium, calcium, and 
 sodium borates (pp. 206, 212, 227) ; and rarely as an iron borate (p. 182), 
 or ammonium borate (p. 231). It also occurs in the silicates, tourma- 
 line, danburite, axinite, and datolite, in which it is easily detected by 
 the blowpipe reaction (p. 87). 
 
 Ill. THE ARSENIC GROUP. 
 
 The elements of the Arsenic group occurring among 
 minerals are, arsenic, antimony, bismuth, phosphorus, ni- 
 trogen, vanadium, tantalum, columbium. Of these arsenic, 
 antimony, and bismuth occur native, and as sulphides ; also, 
 in combination with other metals, constituting arsenides, 
 antimonides, bismutides ; and, along with sulphur also, mak- 
 ing sulpharsenites, sulphantimonites, sulphbismutites. In 
 addition, they all, excepting bismuth, enter into the consti- 
 tution of a series of native ternary oxygen compounds or 
 salts, called severally, arsenates, antimonates, phosphates, 
 nitrates, vanadates, tantalates, columbates. 
 
 The chief oxide has the general formula R, O;. 
 
 Native Arsenic. 
 
 Rhombohedral. RA R—=85° 41’. Cleavage basal, imper- 
 fect, Also massive, columnar, or granular. 
 
THE ARSENIC GROUP. 99 
 
 Color and streak tin-white, but usually dark grayish from 
 tarnish. Brittle. H.=3°5. G.=5°65-5°90. 
 
 B.B. volatilizes very readily before fusing; with the odor 
 of garlic; also burns with a pale bluish flame when heated 
 just below redness. 
 
 Obs. Occurs with silver and lead ores. It is found in 
 considerable quantities at the silver mines of Freiberg and 
 Schneeberg; also in Bohemia, the Hartz, at Kapnik in 
 Upper Hungary, in Siberia in large masses, and elsewhere. 
 
 In the United States it has been observed at Haverhill 
 and Jackson, N. H., and at Greenwood, Me. 
 
 Orpiment.—Yellow Arsenic Sulphide. 
 
 Trimetric. Cleavage highly perfect in one direction. In 
 foliated masses, and sometimes in prismatic crystals. Color 
 and streak fine yellow. Lustre brilliant pearly, or metallic 
 pearly, on the face of cleavage. Subtransparent to translu- 
 cent; sectile. H.=1°5-2. G.=3°4-3°5. 
 
 Composition. As,S,=Sulphur 39:0, arsenic 61:0. Wholly 
 evaporates before the blowpipe with an alliaceous odor, and 
 on charcoal burns with a blue flame. 
 
 From Hungary, Koordistan in Turkey in Asia, China, and 
 South America. Occurs at Edenville, N. Y., as a yellow 
 powder, resulting from the decompositon of arsenical iron. 
 
 Realgar is another arsenic sulphide. It has a fine clear red color, 
 aurora red to orange, and occurs transparent or translucent ; H.= 
 15-2 ; G.=3-35-3:65 ; Composition, As S=Sulphur 29:9, arsenic 70:1. 
 Like the preceding before the blowpipe. From Hungary, Bohemia, 
 Saxony, the Hartz, Switzerland, and Koordistan in Asiatic Turkey. 
 It has been observed in the lavas of Vesuvius. 
 
 Realgar is one of the ingredients of white Indian fire, often used as a 
 signal light. Orpiment is a coloring ingredient in the pigment called. 
 king’s yellow, in which it is mixed with arsenious, acid. 
 
 Arsenolite—White Arsenic. 
 
 Isometric. In minute capillary crystals, and botryoidal 
 or stalactitic. Color white. Soluble; taste astringent, 
 sweetish. H.=1°5. G.=3°%. 
 
 Composition. As, O,= Arsenic 75-8, oxygen 24:°2=100. 
 
 This is the same compound with the common arsenic of 
 the shops. It is found but sparingly native, accompanying 
 ores of silver, lead, and arsenic in the Hartz, Bohemia, and 
 elsewhere. It is’a well-known poison. 
 
100 DESCRIPTIONS OF MINERALS. 
 
 Claudetite is the same compound in trimetric crystallizations, from 
 Portugal. 
 
 General Remarks.—Arsenic is obtained for commerce chiefly from 
 arsenopyrite (or mispickel), an iron sulph-arsenide, and from the nickel 
 and cobalt arsenides, by first roasting off the sulphur, and then con- 
 densing the arsenic, in the state of As, O, (“ arsenous acid ”’) in large 
 chambers. To obtain the material pure it is usually sublimed again 
 in iron pots, in the upper part of which (artificially kept cool) it is 
 condensed, mostly in a half-fused vitreous condition. To.reduce the 
 oxide to the metallic state it is heated with charcoal. In Devon and 
 Cornwall the arsenical ores occur with the tin ore, and a large amount 
 of white arsenic is made. The metal arsenic forms a small part of 
 some alloys; the most important is that with lead for shot making. 
 
 Native Antimony. 
 
 Rhombohedral ; RA R=87° 35’. Usually massive, with a 
 very distinct lamellar structure ; sometimes granular. Color 
 and streak tin-white. Brittle. H.=3-3°5. G.=—6-6-6-%9. 
 
 Composition. Pure antimony, often with a little silver, 
 iron, or arsenic. B.B. on charcoal fuses easily and passes 
 off in white fumes. 
 
 Obs. Occurs in veins of silver and other ores in Dauphiny, 
 Bohemia, Sweden, the Hartz, and Mexico. 
 
 Stibnite.-Gray Antimony. Antimony Sulphide. 
 
 Trimetric. In right rhombic prisms, with striated lateral 
 faces ; J \[=90° 45’. Cleavage in the direction of the shorter 
 diagonal, highly perfect. Commonly diver- 
 gent columnar or fibrous. Sometimes massive 
 granular. 
 
 Color and streak lead-gray; liable to tarn- 
 ish. Lustre shining. Brittle; but thin lami- 
 ne a little flexible. Somewhat sectile. H.=2. 
 G.=4°5-4°62. 
 
 Composition. Sb, 8,=Sulphur 28-2, anti- 
 mony 71:8. Fuses readily in the flame of a 
 candle. B.B. on charcoal it is absorbed, giv- 
 ing off white fumes and a sulphur odor. 
 
 Diff. Distinguished by its extreme fusibility 
 and its vaporizing before the blowpipe. 
 
 Obs. Stibnite occurs in veins with ores of silver, lead, 
 zinc, or iron, and is often associated with barite, spathic 
 iron, or quartz. It occurs at Felssbanya and Schemnitz in 
 Hungary ; at Wolfsberg in the Hartz ; at Briunsdorf near 
 Freiberg; in Auvergne, Cornwall, Spain, and Borneo. 
 
 
 
THE ARSENIC GROUP. 101 
 
 In the United States, it has been found sparingly at Car- 
 mel, Me., Lyme, N. H., and at ‘‘Soldier’s Delight,” Md., 
 in the Humboldt mining region, and in the mines of Aurora, 
 Esmeralda County, Nevada. 
 
 _ This ore affords much of the antimony of commerce. By 
 simple fusion, the crude antimony of the shops is obtained, 
 from which pure antimony and its pharmaceutical prepara- 
 tions are made. 
 
 Allemontite is an arsenical antimony, Sb, As,, from Allemont, and 
 also from Bohemia and the Hartz. 
 
 Valentinite. White antimony in white, grayish, or reddish rect- 
 angular crystals, with perfect cleavage, affording a rhombic prism of 
 186° 58’. Also in tabular masses, and columnar and granular. H,= 
 25-8. G.=5-'57. Lustre adamantineto pearly. Composition, Sb, O, 
 =—Oxygen 16°44, antimony 83:56=100. 
 
 Senarmontite is the same compound in isometric forms. 
 
 Kermesite or red antimony is an antimony oxide and sulphide, in 
 red tufts of capillary crystals. Lustre adamantine. From Hungary, 
 Dauphiny, Saxony, and the Hartz. 
 
 Cervantite. An oxide of antimony, Sb, O,, resulting from the de- 
 composition of stibnite. 
 
 Livingstonite. Like stibnite, but contains 14 per cent. of mercury 
 and has a red streak. From Mexico. 
 
 Native Bismuth. 
 
 Rhombohedral; R A R=87° 40’. Cleavage rhombohedral, 
 perfect. Generally massive, with distinct cleavage ; some- 
 times granular. 
 
 Color and streak silver white, with a slight tinge of red. 
 Subject to tarnish. Brittle when cold, but somewhat mal- 
 leable when heated. H.=2-2°5. G.=9:7-9°8. Fuses at 
 - a temperature of 476° F. 
 
 Composition. Pure bismuth, with sometimes a trace of 
 arsenic, sulphur or tellurium. B.B. on charcoal vaporizes, 
 and leaves a yellow coating on the coal, paler on cooling. 
 
 Obs. Native Bismuth is abundant with ores of silver and 
 cobalt in Saxony and Bohemia, and occurs also in Cornwall 
 and Cumberland, England. At Schneeberg, it forms arbo- 
 rescent delineations in brown jasper. Occurs also in Nor- 
 way, Sweden, Chili and Bolivia; also at the Balhannah 
 mine, in §. Australia, with copper ore and gold. 
 
 In the United States, it has been found at Lane’s and 
 Booth’s mine, Monroe, where it occurs with tungsten, gaienite 
 and pyrite; also at Brewer’s mine, in Chesterfield district, 
 South Carolina ; and in Colorado. 
 
102 DESCRIPTIONS OF MINERALS. 
 
 Bismuthinite. A bismuth sulphide, Bis Sy, in acicular crystals of a 
 lead-gray color. 
 
 Guanajuatite. A bismuth selenide, from Guanajuato, Mexico, called 
 also frenzelite. Silaonite is a selenide from the same locality, of a 
 lead-gray color. 
 
 Bismite. Bismuth ochre, an impure oxide, grayish, to greenish and 
 yellowish white, and massive or earthy, found with native bismuth. 
 
 Tetradymite.—Bismuth Telluride. 
 
 Hexagonal; R A R=81° 2’. Crystals often tubular, with 
 a very perfect basal cleavage. Also massive, and foliated 
 or granular. Lamine flexible, and soil paper. Lustre 
 splendent metallic. Color pale steel-gray, a little sectile. 
 H. =1°5—2. G.=7:2—7°9. 
 
 Composition. Consists of bismuth and tellurium, with some- 
 times sulphur and selenium, affording for the most part the 
 formula Bi, (Te, 8), A variety from Dahlonega, Georgia, 
 gave Tellurium 48°1, bismuth 51:°9=Bi,Te,; G.=7-642. 
 Joseite is a bismuth telluride from Brazil, in which half the 
 bismuth is replaced by sulphur; and Wehrlite is another 
 containing sulphur, from Deutsch Pilsen, Hungary, having 
 G—8°44. 
 
 Obs. Found with gold in Virginia, North Carolina, and 
 Georgia ; Highland, Montana Territory ; Red Cloud Mine, 
 Colorado ; Montgomery Mine, Arizona. 
 
 General Remarks. —The metal bismuth is obtained mostly from 
 native bismuth. Besides the above ores, there are also others in which . 
 the metal is combined with silver, lead, and cobalt (pp. 116, 166) ; 
 and a carbonate of bismuth, which occurs rarely in connection with 
 native bismuth or the ores of the metal, as a result of oxidation ; also 
 a silicate. 
 
 IV. CARBON GROUP. 
 
 The Carbon group in chemistry comprises carbon and 
 silicon, in which the formula for the most prominent oxide 
 is RO, Only carbon occurs native. | 
 
 Carbon occurs crystallized in the diamond and graphite ; 
 as oxides, in carbon oxide, and carbon dioxide (ordinarily 
 called carbonic acid); combined with hydrogen, or hydrogen 
 and oxygen, in bitumen, mineral oils, amber, and a num- 
 ber of native mineral resins, and mineral wax; and as the 
 chief constituent of mineral coal, in which it is combined 
 
CARBON GROUP. 103 
 with more or less of hydrogen and oxygen and usually some 
 nitrogen. 
 
 Diamond. 
 
 Tsometric. In octahedrons, dodecahedrons and more com- 
 plex forms. Faces often curved, as in the figures. Cleavage 
 octahedral ; perfect. 
 
 Eb 
 
 a 
 
 
 
 Color white, or colorless; also yellowish, red, orange, 
 green, blue, brown or black. Lustre adamantine. Trans- 
 parent ; translucent when dark-colored. H.=10. G.= 
 3‘48—3°55. 
 
 Composition. Pure carbon. It burns and is consumed at 
 a high temperature, producing carbonic acid gas. Exhibits 
 vitreous electricity when rubbed. .Some specimens exposed. 
 to the sun for a while, give out light when carried to a dark 
 place. Strongly refracts and disperses light. 
 
 Diff. Diamonds are distinguished by their superior hard- 
 ness; their brilliant reflection of light and adamantine 
 lustre, their vitreous electricity when rubbed, which is not 
 afforded by other gems unless they are polished ; and, by the 
 practiced ear, by means of the sound when rubbed together. 
 
 Obs. The coarse diamonds, unfit for jewelry, are called 
 dort, and the kind in black pebbles, or masses, from Brazil, 
 carbonado. The latter occur sometimes in pieces 1,000 
 carats in weight ; they have G.=8 to 3-42. Another kind is 
 much like anthracite, G. =1-66, although as hard as diamond 
 crystals ; it is in globules or mammillary masses, often partly 
 made up of concentric layers. 
 
 Diamonds occur in India, in the district between Golconda 
 and Masulipatam, and near Parma, in Bundelcund, where 
 some of the largest have been found ; also on the Mahanuddy, 
 
104 DESCRIPTIONS OF MINERALS. 
 
 in Ellore. In Borneo, they are obtained on the west side of 
 the Ratoos Mountain, with gold and platina. The Brazilian 
 mines were first discovered in 1728, in the district of Serra 
 do Frio, to the north of Rio de Janeiro ; the most celebrated 
 are on the river Jequitinhonha, which is called the Diamond 
 River, and the Rio Pardo; seventy to seventy-five thousand 
 carats are exported annually from these regions. In the 
 Urals of Russia they had not been detected till July, 1829, 
 when Humboldt and Rose were on their journey to Siberia. 
 The river Gunil, in the province of Constantine, in Africa, 
 is reported to have afforded some diamonds. 
 
 In South Africa, where they were first discovered in 1867, 
 they occur in the gravel of the Vaal River, and in the 
 Orange River country. The value of the diamonds obtained 
 up to November, 1875, has been estimated as exceeding 
 60,000,000 of dollars. 
 
 In the United States, the diamond has been met with in 
 Rutherford County, North Carolina; Hall County, Georgia ; 
 also Franklin County, North Carolina; in Manchester, 
 opposite Richmond, Virginia; also in Cherokee Ravine, 
 Butte County, Forest Hill in El Dorado County (one weigh- 
 ing nearly 5°62 grains), Fiddletown in Amador County, and 
 in Nevada County, California; and on the coast of Southern 
 Oregon. It has been reported from Idaho. 
 
 The original rock in Brazil appears to be either a kind of 
 laminated granular quartz, called itacolumyte ; or a ferru- 
 ginous quartzose conglomerate. The itacolumyte occurs in 
 the Urals, and diamonds have been found in it; and it is 
 also abundant in Georgia and North Carolina. In India, 
 the rock is a quartzose conglomerate. The origin of the 
 diamond has been a subject of speculation, and it is the 
 prevalent opinion that the carbon, like that of coal and 
 mineral oil, is of vegetable or animal origin. Some crystals 
 have been found with black uncrystallized particles or seams 
 within, looking like coal; and this fact has been supposed 
 to indicate such an origin. 
 
 Diamonds, with few exceptions, are obtained from allu- 
 vial washings. In Brazil, the sands and pebbles of the 
 diamond rivers and brooks (the waters of which are drawn 
 off in the dry season to allow of the work) are collected and 
 washed under a shed, by a stream of water passing through 
 a succession of boxes. A washer stands by each box, and 
 inspectors are stationed at intervals. 
 
CARBON GROUP. 105 
 
 Diamonds are valued according to their color, transpa- 
 rency and size. ‘The rose diamond is more valuable than 
 the pure white, owing to the great beauty of its color and 
 its rarity. The green diamond is much esteemed on account 
 of its color. ‘The blue is prized only for its rarity, as the 
 color is seldom pure. ‘The black diamond, which is uncom- 
 monly rare and without beauty, is highly prized by collec- 
 tors. The brown, gray and yellow varieties are of much less 
 value than the pure white or limpid diamond. 
 
 The largest diamond of which we have any knowledge is 
 mentioned by Tavernier, as in the possession of the Great 
 Mogul. It weighed originally 900 carats, or 2,769°3 grains, 
 but was reduced by cutting to 861 grains. It has the form 
 and size of half of a hen’s egg. It was found in 1550, in 
 the mine of Colone. The diamond which formed the eye 
 of a Braminican idol, and was purchased by the Empress 
 Catherine II. of Russia from a French grenadier who had 
 stolen it, weighs 1943 carats, and is as large as a pigeon’s 
 egg. ‘The Austrian crown has a diamond weighing 1394 
 carats. The Pitt or Regent diamond is of less size, 1t weighing 
 but 136-25 carats, or 4191 grains ; but on account of its un- 
 blemished transparency and color, it is considered the most 
 splendid of Indian diamonds. It was sold to the Duke of 
 Orleans by Mr. Pitt, an English gentleman, who was gover- 
 nor of Bencolen, in Sumatra, for £130,000. It is cut in the 
 form of a brilliant, and is estimated at £125,000. The 
 Rajah of Mattan has in his possession a diamond from Bor- 
 neo, weighing 367 carats. The Koh-i-noor, on its arrival 
 in England, weighed 186-016 carats.* It is said by Taver- 
 nier to have originally weighed 7874 carats. It has since 
 been recut and reduced one-third in weight. 
 
 In the Dresden ‘Treasury there is an emerald green dia- 
 mond, weighing 314 carats. The Hope diamond, weighing 
 441 carats, has a beautiful sapphire-blue color. 
 
 The diamonds of Brazil are seldom large. Maure men- 
 tions one of 120 carats, but they rarely exceed 18 or 20. 
 One weighing 2544 carats, called the ‘Star of the South,” 
 was found in 1854. 
 
 Of South African diamonds, the ‘‘ Schreiner” weighed, 
 
 
 
 * A carat is a conventional weight, and is divided into 4 grains, which are a little 
 ighter than 4 aa troy; 74 1-16 carat grains are equal to 72 troy grains. The term 
 carat is derived from the name of a bean in Africa, which, ina dried state, has long 
 been used in that country for weighing gold. These beans were early carried to 
 India, and were employed there for weighing diamonds. 
 
106 DESCRIPTIONS OF MINERALS, 
 
 in itsrough state, 308 carats ; and the “Stewart,” which has 
 a light straw color, 288°35 carats. The diamonds of South 
 Africa are mostly “off color;” about 10 per cent. are of 
 first quality ; 15, 2d; 20, 3d; and 55 per cent. are dort (W. 
 J. Morton). The ‘‘Star of South Africa,” of pure water, 
 weighed 83-5 carats. Some crystals crack to pieces after 
 being exposed to the air awhile. 
 
 The diamond is cut by taking advantage of its cleavage, and. 
 also by abrasion with its own powder. The flaws are some- 
 times removed by cleaving it. Afterwards the crystal is fixed 
 to the end of a stick of soft solder when the solder is in a 
 half-melted state, leaving the part projecting which is to be 
 cut. Acircular plate of soft iron is then charged with the 
 powder of the diamond, and this, by its revolution, grinds 
 and polishes the stone. By changing the position, other 
 facets are added in succession till the required form is ob- 
 tained. Diamonds were first cut in Europe, in 1456, by Louis 
 Berquen, a citizen of Bruges ; but in China and India, the art 
 of cutting appears to have been known at a very early period. 
 
 By the above process, diamonds are cut into brilliant, rose 
 and table diamonds. ‘The brilliant has a crown or upper 
 part, consisting of a large central eight-sided facet, and a 
 series of facets around it; and a colle¢, or lower part, of py- 
 ramidal shapes, consisting of a series of facets, with a maller 
 series near the base of the crown. ‘The depth of a brilliant 
 is nearly equal to its breadth, and it therefore requires a 
 thick stone. Thinner stones, in proportion to the breadth, 
 are cut into rose and table diamonds. ‘The surface of the 
 rose diamond consists of a central eight-sided facet of small 
 size, eight triangles, one corresponding to each side of the 
 table, eight trapeziums next, and then a series of sixteen tri- 
 angles. The collet side consists of a minute central octagon, 
 surrounded by eight trapeziums, corresponding to the angles 
 of the octagon, each of which trapeziums is subdivided by a 
 salient angle into one irregular pentagon and two triangles. 
 The table is the least beautiful mode of cutting, and is used 
 for such fragments as are quite thin in proportion to the 
 breadth. It has a square central facet, surrounded by two 
 or more series of four-sided facets, corresponding to the sides 
 of the square. 
 
 Diamonds have also been cut with figures wpon them. As 
 early as 1500, Charadossa cut the figure of one of the Fathers 
 of the church on a diamond, for Pope Julius I. 
 
CARBON GROUP. 107 
 
 Diamonds are employed for cutting glass; and for this 
 purpose only the natural edges of crystals can be used, and 
 those with curved faces are much the best. Diamond dust 
 is used to charge metal plates of various kinds for jewelers, 
 lapidaries and others. Those diamonds that are unfit for 
 working, are sold for various purposes, under the name of 
 bort. Drills are made of small splinters of bort, and used. 
 for drilling other gems, and also for piercing holes in artifi- 
 cial teeth and vitreous substances generally ; and, others of 
 iron set with a few diamonds, for drilling rocks. 
 
 Graphite.—Plumbago. 
 
 Hexagonal. Sometimes in six-sided prisms or tables with 
 a transversely foliated structure. Usually foliated, and mas- 
 sive; also granular and compact. 
 
 Lustre metallic, and color iron-black to dark steel-gray. 
 Thin laminew flexible H.=1-2. G.=2:25-227. Soils 
 paper, and feels greasy. | 
 
 Composition. Commonly 95 to 99 per cent. of carbon. 
 B.B. infusible, both alone and with reagents; not acted 
 upon by acids. 
 
 Diff. Resembles molybdenite, but differs in being unat- 
 fected by the blowpipe and acids. The same characters dis- 
 tinguish the granular varieties from any metallic ores they 
 resemble. 
 
 Obs. Graphite (called also black lead) is found in crys- 
 talline rocks, especially in gneiss, mica schist and oranular 
 limestone; also in granite and argillyte. Its principal Eng- 
 lish locality at Borrowdale, in Cumberland, is now nearly 
 exhausted. he te 
 
 In the United States graphite occurs in large masses in 
 veins in gneiss at Sturbridge, Mass. It is also found in 
 North Brookfield, Brimfield and Hinsdale, Mass. ; abundant 
 at Roger’s Rock, near Ticonderoga ; near Fishkill Landing in 
 Dutchess County ; at Rossie, in St. Lawrence County, and 
 near Amity, in Orange County, N. Y. 5 at Greenville, N. C.; 
 in Cornwall, near the Housatonic, and in Ashford, Ct.; near 
 Attleboro, in Bucks County, Penn.; in Brandon, Vermont ; 
 in Wake, North Carolina; on Tyger River, and at Spartan- 
 burg, near the Cowpens Furnace, South Carolina ; also 
 abundantly and of excellent quality in Canada, in Bucking- 
 ham, Fitzroy and Grenville. 
 
108 DESCRIPTIONS OF MINERALS. 
 
 For the manufacture of the best pencils the granular 
 graphite was thought necessary, and hence the former great 
 value of the Borrowdale mine, where the texture was pecu- 
 liarly fine and firm. But now the graphite is ground up, 
 and then compressed under heavy pressure, and thus the 
 fine texture and firmness required may be obtained with any 
 pure graphite. At Sturbridge, Mass., it is rather coarsely 
 granular and foliated, and has been extensively worked. 
 The mines of Ticonderoga and Fishkill Landing, N. ¥. ; 
 of Brandon, Vt. ; and of Wake, North Carolina, are also 
 worked ; and that of Ashford, Ct., formerly afforded a large 
 amount of graphite, though now the works are suspended. 
 
 Graphite is extensively employed for diminishing the 
 friction of machinery ; also for the manufacture of crucibles 
 and furnaces ; and as awash for giving a gloss to iron stoves 
 and railings. For crucibles it is mixed with half its weight 
 of clay. 
 
 Carbonic Acid. 
 
 Carbonic acid—carbon dioxide of existing chemistry—is 
 the gas that gives briskness to the Saratoga and many other 
 mineral waters, and to artificial soda water. Its taste is 
 slightly pungent. It extinguishes combustion and destroys 
 life. 
 
 Composition. C O,= Oxygen 72:35, carbon 27°65 =100. 
 
 This gas is contained in the atmosphere, constituting 
 about 4 parts, by volume, in 10,000 parts; and it is present 
 in minute quantities in the waters of the ocean and land. It 
 is given out by animals in respiration, and is one of the re- 
 sults of animal and vegetable decomposition ; and from this 
 source the waters derive much of their carbonic acid. This 
 gas is the choke-damp of mines, where it is often the occasion 
 of the destruction of life. It is often present also in wells. 
 
 Carbon dioxide (or carbonic acid) is given out by lime- 
 stone (or calcium carbonate) when it is heated ; and quick- 
 lime is limestone from which C O, has been expelled by heat, 
 a process carried on usually in a limekiln. It is also driven 
 from limestone by the action of sulphuric acid, with the for- 
 mation of gypsum (a hydrous calcium sulphate), or anhy- 
 drite (an anhydrous calcium sulphate). These processes are 
 often carried on in volcanoes, and hence carbonic acid gas is 
 common in some volcanic regions. ‘The Grotto del Cane 
 (Dog Cave) at the Solfatara near Naples, is a small cavern 
 
x GOLD. 109 
 filled to the level of the entrance with this gas. It is a com- 
 mon amusement for the traveler to witness its effect upon a 
 dog kept for that purpose. He is held in the gas awhile and 
 is then thrown out apparently lifeless ; in a few minutes he 
 recovers himself, picks up his reward, a bit of meat, and runs 
 off as lively asever. Ifcontinued in the carbonic acid gas a 
 short time longer, life would have been extinct. 
 
 Carbonic acid, under high pressure, becomes a liquid, and, 
 with pressure and cold, a white snow-like solid. In the hquid 
 state it is often found in microscopic globules in the inte- 
 . rior of crystallized quartz, topaz, and some other minerals ; 
 and when this is true, calcite (calcium carbonate) is often 
 present in the same or an adjoining rock. 
 
 Besides the calcium carbonate in nature, there are also 
 carbonates of ammonium, sodium, barium, strontium, mag- 
 nesium, iron, manganese, zinc, copper, lead, nickel, cobalt, 
 bismuth, uranium, cerium, and lanthanum. 
 
 II. MINERALS CONSISTING OF THE BASIC 
 ELEMENTS WITH OR WITHOUT ACIDIC— 
 THE SILICATES EXCLUDED. 
 
 I, GOLD. 
 
 Gold occurs mostly native, being either pure, or alloyed 
 with silver and other metals. It is occasionally found min- 
 eralized by tellurium, making part of the valuable minerals 
 Sylvanite, Nagyagite and Petzite. It occurs often dissemi- 
 nated through pyrite and galenite in auriferous regions, 
 rendering these minerals valuable sources of gold. 
 
 Native Gold. 
 
 Isometric. In octahedrons, dodecahedrons ; without cleay- 
 age. Also in arborescent forms, consisting of strings of 
 crystals, filiform, reticulated, in grains, thin lamine and 
 masses. 
 
 Color various shades of gold-yellow, becoming pale from 
 alloy with silver; occasionally nearly silver-white from 
 the silver present. Eminently ductileand malleable. H.= 
 25-3. G.—12-20, varying according to the metals alloyed 
 with the gold. Fuses at 2,016° F. (1,102° C.) 
 
110 DESCRIPTIONS OF MINERALS. 
 
 Composition. Native gold usually contains silver, and in 
 very various proportions ; and the color becomes paler with 
 the increase of silver. he finest native gold from Russia 
 
 
 
 yielded gold 98-96, silver 0°16, copper 0°35, iron 0°05 ; 
 G.=19:099. A gold from Marmato afforded only 73°49 per 
 cent. of gold, with 26-48 per cent. of silver ; G18 06R 
 This last is in the proportion of 8 of gold to 2 of silver. The 
 following proportions also have been observed : 34 to 2; 5 
 to 2; 8to1l; 4 tol, and this the most common ; 6 tol is 
 also of frequent occurrence. Average of California native 
 gold is 88 per cent. gold, and the range mostly between 87 
 and 89; the range of the Canadian, mostly between 85 and 
 90; of Australian, between 90 and 96 per cent., and the 
 average 934. ‘The Chilian gold afforded Domeyko 84 to 96 
 per cent. of gold, and 15 to 3 per cent. of silver. The more 
 argentiferous gold has been called Llectrum; the atomic pro-, 
 portion of 1:1 between the gold and silver corresponds to 
 35°5 per cent. of silver, and that of 2:1, to 21°6 per cent. 
 
 Copper is occasionally found in alloy with gold, and some- 
 times also iron, bismuth, palladium andrhodium. A rhodiwm- 
 gold from Mexico gave the specific gravity 15°5-16°8, and 
 contained 34 to 43 per cent. of rhodium. A bismuth gold 
 has been called Maldonite. 
 
 Diff Tron and copper pyrites are often mistaken for gold 
 by those inexperienced in ores ; but these are brittle minerals, 
 while gold may be cut in slices, and flattens under a hammer. 
 Pyrite is too hard to yield at all to a knife, and copper 
 pyrites affords a dull greenish powder. Moreover pyrite 
 gives off sulphur when strongly heated, while gold melts 
 without odor, 
 
GOLD. 111 
 
 Obs, Native gold is mostly confined to quartz, intersect- 
 ing in veins, or interlaminated with, subcrystalline slaty or 
 schistose rocks, especially hydromica and chloritic slates, It 
 occurs sparingly in similar or other veins in granite, gneiss, 
 or mica slate. It has also been found in traces, according 
 to J. J. Stevenson, in the trachytes of Colorado, and in 
 Silurian and Carboniferous quartzytes, 
 
 The quartz intersects the slaty rocks in veins and lies in 
 thick seams between their layers. It is frequently cellular 
 for a considerable distance from the surface owing to the 
 alteration and removal of pyrite, galena, or other metallic 
 ores that may be accompaniments of the gold, and the 
 cavities are usually rusty with oxide of iron, and sometimes 
 contain particles of sulphur left by the decomposing pyrite, 
 and also strings or lamine of gold. The rock in this cav- 
 ernous state is rather easily quarried out; but deep below, 
 where the minerals are not removed by decomposition, mining 
 is far more difficult. 
 
 Pyrite itself is nearly as hard as quartz, when unaltered, 
 and readily strikes fire with a steel. This pyrite is often 
 very abundant, and contains throughout it considerable 
 gold; but the gold is so finely distributed, that little of it 
 can be removed by the ordinary process of crushing and 
 amalgamation; nature’s way consists in decomposing the 
 pyrite and thereby making it drop its load. ‘The galenite 
 of a gold region is also usually auriferous. 
 
 Gold sometimes occurs in the slate rocks adjoining the 
 veins, though mostly confined to the latter. Auriferous 
 quartz often contains no gold visible to the naked eye. 
 
 But while quartz veins are to a large extent the actual 
 repositories of the gold in its native state, a very large 
 part of the gold derived from auriferous regions has come 
 from the sand and gravel beds, in which it occurs in flat- 
 tened grains, and sometimes in lumps and nuggets. By dif- 
 ferent methods—erosion by running waters, movements of 
 glaciers, natural decomposition, and other disintegrating 
 action—the gold-bearing rocks have been extensively, re- 
 duced to earth and stones, and this loose material has been 
 distributed along the river courses, making vast alluvial or 
 diluvial gravelly formations. From these gravels the gold 
 is obtained by simple washing, thus taking advantage of the 
 high specific gravity of gold. Streams are carried in aque- 
 ducts and thrown in great jets against the gravel blufis to 
 
112 DESCRIPTIONS OF MINERALS, 
 
 reduce the material to loose earth and prepare it for further 
 washing by the same water in sluices arranged for the pur- 
 pose. 
 
 The minerals most common in gold regions are platinum, 
 iridosmine, magnetite, pyrite, galenite, ilmenite, chalco- 
 pyrite, blende, tetradymite, zircon, rutile, barite ; also in 
 some cases wolfram, scheelite, brookite, monazite and dia- 
 mond. Platinum and iridosmine accompany the gold of 
 the Urals, Brazil and California; and diamonds are found 
 in the gold region of Brazil, and occasionally in the Urals 
 and United States. 
 
 Gold is widely distributed over the globe. In AMERICA, 
 it occurs in Brazil (where formerly a greater part of that 
 used was obtained) along the chain of mountains which 
 runs nearly parallel with the coast, especially near Villa 
 Rica, and in the province of Minas Geraes ; in New Granada, 
 at Antioquia, Choco and Giron; in Chili; sparingly in Peru 
 and Mexico; in Arizona; in the Coast Range, and, much 
 more abundantly, in the Sierra Nevada, California; im 
 Oregon, British Columbia and Alaska; in New Mexico, 
 Colorado, and Wyoming, and other parts of the Rocky 
 Mountain region; in the Appalachians from Virginia to 
 Georgia, a region that formerly produced annually nearly a 
 million of dollars; very sparingly in Vermont, New Hamp- 
 shire, and other New England States; in Nova Scotia; in 
 Beauce County, Canada; also, north of Lake Superior ; 
 and in the gravel of Illinois and Indiana. 
 
 In Europe, it occurs sparingly in Cornwall and Devon, 
 England ; North Wales, Scotland, and Ireland, formerly in 
 the County of Wicklow, where a nugget of 22 ounces was 
 found; and in France, very sparingly in the Department of 
 Isére ; in the sands of the Rhine, the Reuss, and the Aar ; 
 in Tyrol and Salzburg ; on the southern slope of the Pen- 
 nine Alps, from the Simplon and Monte Rosa to the Valley 
 of Aosta, Northern Piedmont, where nearly 6,000 ounces 
 were obtained in 1867; more abundantly in Hungary, at 
 Konigsberg, Schemnitz and Felsobanya, and in ‘Transyl- 
 vania, at Kapnik, Voréspatak and Offenbanya ; in Spain, 
 formerly worked in Asturias ; in Sweden, at Edelfors. 
 
 In the Urals are valuable mines at Beresof, and other 
 places on the eastern or Asiatic flank of this range, and the 
 comparatively level portions of Siberia; also in the Altai 
 Mountains. Also in the Cailas Mountains in Little Thibet ; 
 
GOLD, 113 
 
 sparingly in the rivers of Syria and other parts of Asia 
 Minor ; in Ceylon, China, Japan, Formosa, Java, Sumatra, 
 Western Borneo, the Philippines, and New Guinea. 
 
 In Arrica, at Kordofan, between Darfour and Abyssinia ; 
 also south of Sahara, in the western part of Africa, from 
 the Senegal to Cape Palmas ; also along the coast opposite 
 Madagascar, between the 22d and 35th degrees south lati- 
 tude, in the Transvaal Republic. Other regions are Tas- 
 mania, New Zealand, and New Caledonia. 
 
 _ General Remarks.—The most productive gold regions at the present 
 time are those of Australia and California. 
 
 In Australia the richest mines are those of Victoria and New South 
 Wales, Victoria yielded, in 1856, 3,000,000 ounces, and in 1875, 1,195, - 
 250 ; Australia, in 1875, 227,000 ounces. The Australian gold was 
 first made known to the world in 1851. The localities discovered 
 were on Summer Hill Creek and the Lewis Pond River (near lat. 33° 
 N., long. 149°-150° E.), streams which run from the northern flank 
 of the Coriobolas down to the river Macquarie, a river flowing west- 
 ward and northward ; it was soon afterward found on the Turon 
 River, which rises in the Blue Mountains; and finally a region of 
 country 1,000 miles in length, north and south, was proved to be 
 auriferous ; the country is a region of metamorphic rocks, granite and 
 slates, and in many parts abounds in quartz veins. Queensland and 
 South Australia, and also Tasmania and New Zealand, afford some 
 gold. 
 
 The first discovery of gold in California was made early in the 
 spring of 1848, on the American Fork, a tributary to the Sacramento, 
 near the mouth of which Sutter’s establishment was situated. Soon 
 Feather River, another affluent, 18 or 20 miles north, was also proved 
 to abound in gold about its upper portions ; and it was not long after 
 before each stream in succession, north and south, along the western 
 slope of the Sierra Nevada was found to flow over auriferous sands. 
 The gold as now developed extends along that chain, through the 
 whole length of the great north and south valley which holds the 
 rivers and plains of the Sacramento and San Joaquin. It continues 
 south nearly to the Tejon pass, in latitude 85°, and north beyond the 
 Shasta Mountains to the Umpqua, and less productively into Oregon 
 and Washington Territories, and in British Columbia. Gold also 
 occurs in some places in the coast range of mountains, Even the 
 very site of San Francisco has been found to contain traces. North 
 of Shasta Mountain there are important mines on the Klamath and 
 the Umpqua, and some of the best on the sea-shore between Gold 
 Bluff, in 41° 30’ south of the Klamath (80 miles south of Crescent City) 
 tothe Umpqua. What once was Rogue River is now called Gold River. 
 
 In Colorado, gold mines occur in Gilpin County, and much less pro- 
 ductively in Clear Creek, Park, Boulder, Lake, Summit, and Southern 
 counties ; and the yield in 1874 amounted to $2,102,487, of which 
 $1,525,447 were from Gilpin County. 
 
 Nevada produced from the Comstock lode (see p. 123), in 1875, gold 
 to the amount of about $11,740,000, and the rest of Nevada, $2,256,000, 
 
 8 
 
114 DESCRIPTIONS OF MINERALS. 
 
 making in all nearly $14,000,000; and in 1876, the Comstock lode 
 yielded $18,000,000, and the rest of Nevada about $1,338,000. 
 
 The yield of the United States in gold in the years 1870 to 1876, is 
 stated as follows in a note dated February 5, 1877, by J. J. Valentine, 
 in Jones’s ‘‘ Report of the Silver Commission (1877)” : 
 
 * (5) ent Meme nen ap ei a oer hee $33,750,000 
 ey Cet Wen at weet ere er ntce 34,398,000 
 1Ryo ie Noe a eee 88,109,895 
 aqeer Zant). ieee 39,206,558 
 LOY ck es ah ae Se 38,466,488 
 HOY Cee CE | ek tere 39,968,194 
 1O7Gu ve Saou Se eee eee ee 42,886,985 
 
 The amount, in 1874, from California is stated at $17,620,000 ; from 
 Oregon, $609,000 ; Washington, $155,500 ; Idaho, $1,828,430 ; Mon- 
 tana, $2,850,000 ; Utah, $92,000 ; Arizona, £25,700 ; Colorado, $2,- 
 102,487 ; Mexico, $84,655 ; British Columbia, $1,636,200. 
 
 According to the Report of A. del Mar, in the ‘‘Report of the Sil- 
 ver Commission of 1877,” the yield of gold from all America from 
 1492 to the year 1800, was $1,872,300,000. From 1800 to 1847 inclu- 
 sive, 48 years, the yield from America, Europe, and Africa is stated at 
 # 429,200,000 ; and from 1848 to 1876 inclusive, 29 years, $3,381,500, - 
 000. The largest annual amount was produced in the year 1856, 
 in which the yield was $147,600,000 ; and next to this, in 1859, with 
 $144,900,000 ; as shown in the annexed table, giving the amounts 
 in millions of dollars : 
 
 1848....... 67°5 1858... ..% 144°6 1863 Sze 109-7 
 TBA To es 870 dhe) Fan 144°9 LEG). ape 106°2 
 USSU aes = s 93°2 1360.0, = ae 119°3 1870... 106-9 
 ga) Brena 120°0 1861. oes 113°3 TST ae 1070 
 § Esti ao 193°7 ASO cian 107°8 LBs eg 99°6 
 16535. aes 155°0 1868.5 sp 107°0 Rbever Rea 97-2 
 1854......- 127°0 1864..... 113°0 1874... 90°8 
 BDO. (pees 185°0 TED uses 130°7 TET ihasee 97°5 
 A1B56.2.0 oss 147°6 1866... .. 122°2 ISiG-n see 90°0 
 TRO ac. eas 133°3 TSG ois rone 114°0 
 
 The total amount for these years is 3 381,500,000. ‘The followiug 
 table is taken from a Report to the British House of Commons in 1876 
 __the amount for the United States only being corrected : 
 
 
 
 
 
 
 
 
 
 
 
 ° Mexico and 
 : United x ei Other 
 Russia. States. Nell Australia. Covntrisas Total. 
 1850 ...|$16,950,000 $27,500,000E| 2. -<--c0- | tpeeee eae teen ete rire ena 
 1855....| 14,200,000 73,700,000 | $5,000,000 $60,325,000 $2,500,000 $155,725,009 
 1860 ...| 15,265,000 46,000,000 4,500,000 2,500,000 2.500,000 120,765,000 
 1865....| 16,185,000 53,225,000 4,000,000 44,100,000 2,500,000 119,960,000 
 
 1870,...| 222070,000 | 33,750,000 | 2,500,000 | 29,150,000 | 2,500,000 89,970,000 
 1875 | 20,000,000 | 40,000,000 | 3,750,000 | 28,750,000 | 2,500,000 95,000,000 
 
 Ee 
 
_ GOLD. 115 
 
 Masses of gold of considerable size have been found in North Cary 
 lina. The largest was discovered in Cabarrus County; it weighed 
 28 pounds avoirdupois (‘‘ steel-yard weight,” equals 37 pounds troy), 
 and was 8 or 9 inches long, by 4 or 5 broad, and about an inch thick. 
 In Paraguay, pieces from 1 to 50 pounds weight were taken from a 
 mass of rock which fell from one of the highest mountains. 
 
 The largest masses of gold yet discovered have been found in aurife- 
 rous gravel. The ‘‘ Blanch Barkley Nugget,” found in South Austra- 
 lia, weighed 146 pounds, and only six ounces of it were gangue ; and 
 one still larger, the ‘‘ Welcome Nugget,” from Victoria, weighed 
 2,195 ounces, or nearly 183 pounds, and yielded £8,376 10s. 6d. sterling 
 of gold. Two others from Victoria weighed 1,621, and 1,105 ounces. 
 In Russia, a mass was found in 1842, near Miask, weighing 96 pounds 
 troy ; another of 27 pounds, and several of 16 pounds have been found 
 in the Urals. The largest mass yet reported from California weighed 
 20 pounds. A remarkably beautiful mass, consisting of a congeries of 
 crystals, weighing 201 ounces (value $4,000), was found in 1865, seven 
 miles from Georgetown, in El Dorado County. 
 
 The origin of gold veins, or rather of the gold in the veins, is little 
 understood. The rocks, as has been stated, are metamorphic slates 
 that have been crystallized by heat; and they are the hydromica, 
 chloritic, and argillaceous, that have been but imperfectly crystal- 
 lized, rather than the mica schist and gneiss, which are well crystal- 
 lized ; and the veins of quartz which contain the gold, occupy fissures 
 through the slates, and openings among the layers, which must have 
 been made when the metamorphic changes or crystallization took 
 place. It was a period, for each gold region, of long-continued heat 
 (occupying, probably, a prolonged age), and also of vast upliftings and 
 disturbances of the beds ; for the beds are tilted at various angles, 
 and the veins show where were the fractures of the layers, or the sep- 
 arations and gapings of the tortured strata. The heat appears not to 
 have been of the intensity required for the better crystallization of the 
 more perfectly crystalline schists. The quartz veins could not have 
 been filled from below, by injection; they must have been filled 
 either laterally, or from above. In all such conditions of upturning 
 and metamorphism, the moisture present would have become intensely 
 heated, and hence have had great dissolving and decomposing power ; 
 it would have taken up silica with alkalies from the rocks (as happens 
 in all Gerdee regions), along with whatever other mineral substances 
 were capable of solution or removal; and the vapor, thus laden, 
 would have filled all open spaces, there to make depositions of the 
 silica and other ingredients it contained. These mineral ingredients 
 would have been derived either from the rock adjoining the veins or 
 opened spaces, or from depths below through ascending vapors. By 
 one or both of these means, the quartz must have received its gold, 
 pyrite, and ores of lead, copper and other materials—all having been 
 carried into the open cavities at the same time with the silica or 
 quartz. The pyrite of the vein is usually auriferous, showing that it 
 was crystallized under the same circumstances that attended the de- 
 positing of the gold in strings, crystals, and grains ; and the same is 
 often true of the galena. 
 
 Calaverite is a bronze-yellow gold telluride. AuTe,=Tellurium 
 
116 DESCRIPTIONS OF MINERALS. 
 
 55°5, gold 44:5—100, with a little silver, occurring massive at the Stan- 
 islaus Mine, California, and the Red Cloud Mine, Colorado, and alse 
 the Keystone and Mountain Lion mines, in the Magnolia District. 
 
 Krennerite is another gold telluride. 
 
 Sylvanite, called also Graphic tellurium, is a telluride of gold and 
 silver, also containing sometimes antimony and more or less lead (see 
 p. 118). 
 
 Nagyagite is a telluride of lead containing 9 to 18 per cent. of gold 
 (see p. 149). 
 
 Petzite is a telluride of silver, allied to Hessite (p. 118), containing 
 gold ; a specimen from Golden Rule Mine, Colorado, contained 25°60 
 per cent, according to Genth. 
 
 Ii. SILVER. 
 
 Silver occurs native, and alloyed, or combined with gold ; 
 also combined with sulphur, selenium, tellurium, arsenic, 
 antimony, bismuth, chlorine, bromine, or iodine ; but never 
 as an oxide, carbonate, sulphate, or phosphate. 
 
 Native Silver. 
 
 Isometric. In octahedrons and other forms. No cleavage 
 apparent. Occurs often in filiform and arborescent shapes, 
 the threads having a crystalline character ; also in lamina, 
 and massive. 
 
 Color and streak silver-white and shining. Often black 
 externally from tarnish. Sectile. Malleable. H.=2°5-3. 
 G. =10°1-11°1. 
 
 Composition. Native silver 1s usually an alloy of silver 
 and copper, the latter ingredient often amounting to 10 per 
 cent. It is algo alloyed with gold, as mentioned under that 
 metal. A bismuth silver from Copiapo, S. A., contained 16 
 per cent. of bismuth. 
 
 B.B. fuses easily to a silver-white globule. Dissolves in 
 nitric acid, from which it is precipitated as white chloride 
 on adding hydrochloric acid. A clean plate of copper 1m- 
 mersed in the nitric solution becomes coated with silver. 
 
 Diff. Distinguished by being malleable ; from bismuth 
 and other white native metals by affording no fumes before 
 the blowpipe; by affording a precipitate with hydrochloric 
 acid which becomes black on exposure. 
 
 Obs. Native silver occurs in masses and string-like ar- 
 borescences, penetrating the gangue, or its minerals, in 
 
SILVER. 117 
 
 various silver mines. It is also found mixed with native 
 copper. . 
 
 The mines of Norway, at Kongsberg, formerly afforded mag- 
 nificent specimens of native silver, but they are now mostly 
 under water. One specimen from this locality, at Copenha- 
 gen, weighs five hundred pounds; and two other masses 
 have been found weighing 238 and 436 pounds. Other Eu- 
 ropean localities are in Saxony, Bohemia, the Hartz, Hun- 
 gary, Dauphiny. Peru and Mexico also afford native silver. 
 A Mexican specimen from Batopilas, weighed when obtained 
 400 pounds ; and one from Southern Peru (mines of Huan- 
 tajaya) weighed over 8 cwt. Arizona is reported to have 
 produced one mass weighing 2,700 pounds. In the United 
 States, in the Lake Superior region, the silver generally pen- 
 etrates the copper in masses and strings, and is very nearly 
 pure, notwithstanding the copper about it. Large masses 
 occur at the Idaho Silver Mine, called the Poor Man’s Lode ; 
 and in strings it is occasionally found in the mines of Ne- 
 vada, California, and Colorado. 
 
 Much of the galena of the world contains avery small per. 
 centage of silver; that of Monroe, Conn., yields nearly 3 
 per cent. 
 
 Native silver has also been observed near the Sing Sing 
 state prison ; at the Bridgewater copper mines, N. J.; and 
 in handsome specimens at King’s Mine, Davidson County, 
 North Carolina. 
 
 Native Amalgam is a compound of silver and mercury. The com- 
 pounds Ag Hg = Silver 35:1, mercury 64:9, or Ag, H, = Silver 26°5, 
 mercury 73°5, are included. Another from Chili having the formula 
 
 Ag,, Hg and containing 86°6 per cent. of silver has been called Ar- 
 querite ; and still another Ag,, Hg, Kongsbergite. 
 
 Argentite._Silver Glance. Sulphuret of Silver. 
 
 Isometric. In dodecahedrons more or less modified. 
 Cleavage sometimes apparent parallel to the faces of the 
 dodecahedron. Also reticulated and massive. 
 
 Lustre metallic. Color and streak blackish lead-gray ; 
 streak shining. Very sectile H.= 22°. G.= 7:19- 
 74, Fs 
 
 Composition. When pure, Ag,S = Sulphur 12:9, silver 
 87:1. B.B. on charcoal in O.F. it intumesces, gives off the 
 odor of sulphur, and finalty affords a globule of silver. 
 
 Diff. Resembles some ores of copper and lead, and other 
 
118 DESCRIPTIONS OF MINERALS. 
 
 ores of silver, but is distinguished by being easily cut, like 
 lead, with a knife; and also by affording a globule of silver 
 on charcoal, by heat alone. Its specific gravity is much 
 higher than that of any copper ores. 
 
 Obs. This important ore of silver occurs in Europe prin- 
 cipally at Annaberg, Joachimstahl, and other mines of the 
 Erzgebirge; at Schemnitz, and Kremnitz, in Hungary, and 
 at Freiberg in Saxony. It is a common ore at the Mexican 
 silver mines, and also in the mines of South America. It 
 occurs in Arizona, with chalcocite, at the Heintzelman Mine, 
 and in Nevada. 
 
 A mass of ‘sulphuret of silver” is stated by Troost to 
 have been found in Sparta, Tennessee. 
 
 Acanthite is a trimetric sulphide of silver, Ag,8, from 
 Joachimstahl ; and Daleminzite, another, from near Frei- 
 berg. 
 
 Stromeyerite. A steel-gray sulphide of silver and copper, Ag,8 
 + Cu,$ = Sulphur 15°7, silver 53°1, copper 31°2:= 100... G. = 626, 
 B.B. it fuses and gives in the open tube an odor of sulphur; but a 
 silver globule is not obtained except by cupellation with lead. From 
 Peru, Silesia, Chili, Siberia, and Arizona. 
 
 Sternbergite. A sulphide of silver and iron containing 83 per cent. 
 of silver. It isa highly foliated ore resembling graphite, and like it 
 leaving a tracing on paper ; the thin lamine are flexible ; color pinch- 
 beck brown ; streak black. From J oachimstahl and Johanngeorgen- 
 stadt. ; 
 
 Naumannite. A selenide of silver and lead in iron-black cubes and 
 massive ; G.=8; contains 738 per cent. of silver. From the Hartz. 
 
 Hessite. A telluride of silver, Ag, Te=Tellurium 37 ‘2, silver 62:8= 
 100. Color between lead-gray and steel-gray. Sectile. G.=8°3—8'6. 
 B.B. in the open tube, faint sublimate of tellurous acid; on char- 
 coal with soda a silver globule. From the Altai; at Nagyag and 
 Retzbanya ; Coquimbo, Chili; Calaveras Co., Cal.; Red Cloud Mine, 
 Colorado ; Kearsarge Mine, Dry Canyon, Utne a 
 
 Petzite is a hessite with the silver replaced in part by gold. G.cs 
 8-7-9-4, Between steel-gray and iron-black. Variety from Golden 
 Rule Mine, afforded Genth Tellurium 3268, silver 41°86, gold 25°60= 
 100-14. Occurs at the same localities with hessite. 
 
 Tapalpite is a telluride of bismuth and silver from Mexico. 
 
 Sylvanite or Graphic Tellurium. A telluride of gold and silver 
 (Ag, Au) Tes=(if Ag : Au=1: 1) Tellurium 55'8, gold 28°5, silver 15°7 
 — 100. Color and streak steel-gray to silver-white, and sometimes nearly 
 brass-yellow. H.=1°5-2. G. —7:99-8'33. Called graphic because of 
 a resemblance in the arrangement of the crystals to writing charac- 
 ters. From Transylvania ; Calaveras Co., California ; Red Cloud and 
 Grand View Mines, Colorado. 
 
 EBucairite, A selenide of silver and copper, containing 42-45 per 
 cent. of silver; color between silver-white and lead-gray ; easily cut 
 by the knife. From Sweden and Chili. : 
 
SILVER. 119 
 
  Dyserasite, or Antimonial Silver, consists simply of silver and anti- 
 mony (78 parts to 22=Ag, Sb), and has nearly a tin-white color. 
 G.—9-4-9°8. B.B. fumes of antimony pass off, leaving finally a 
 globule of silver. From Wolfach, Wittichen, Andreasberg ; also 
 Allemont in Dauphiny ; and Bolivia, 8. A. 
 
 Pyrargyrite.—Ruby Silver. Dark Red Silver Ore. 
 
 Rhombohedral. RAR = 108° 42; RAt-2 = 129° 39". 
 Cleavage parallel to R imperfect. Also massive. Black to 
 dark cochineal-red, with the streak cochi- 
 neal-red and lustre splendent metallic-ada- 
 mantine. H.=2-2°5, G.=5-7-5°9. 
 
 Composition. Ag,8,Sb (=3 Ag, S+S8b, 
 S,)=Sulphur 17-7, antimony 22:5, silver 
 59°8=100. 
 
 B.B. fuses very easily; on charcoal a 
 white deposit of antimony oxide is deposited, 
 and with soda a globule of silver is obtained. In an open 
 tube gives off sulphurous fumes that redden litmus paper. 
 
 Diff. Tis red streak, and its reactions for antimony and 
 silver, are distinctive. | 
 
 Obs. Occurs at Andreasberg ; also in Saxony, Hungary, 
 Cornwall, Mexico, Chili; in Nevada at Washoe ; abundant 
 about Austin, Reese River ; at Poor Man’s Lode, Idaho. 
 
 Proustite, or Light Red Silver Ore, is a related ore con- 
 taining arsenic in place of much or all of the antimony. 
 Composition, Ag, S,As=Sulphur 19-4, arsenic 15:1, silver 
 65°5=100. G.=5°4-5°56. 
 
 B.B. gives a garlic odor. | 
 
 Occurs with pyrargyrite at the above-mentioned localities. 
 
 
 
 Stephanite.—Brittle Silver Ore. Black Silver. 
 
 Trimetric. I, I=115° 39’. No perfect cleavage. Often 
 in compound crystals. Also massive. Streak and color 
 iron-black. H.=2-2°5. G.=6°2%7. 
 
 Composition. Ag,S,8b (=5 Ag. S+8b,8,) = Sulphur 
 16:2, antimony 15:3, silver 68°5. B.B. it gives an odor of 
 sulphur and also fumes of antimony, and yields a dark 
 metallic globule, from which silver may be obtained by the 
 addition of soda. Soluble in dilute nitric acid, and the solu- 
 tion indicates the presence of silver by silvering a plate of 
 copper. 
 
120 DESCRIPTIONS OF MINERALS. 
 
 Obs. Ié occurs with other silver ores at Freiberg, Schnee- 
 berg, and Johanngeorgenstadt, in Saxony ; also in Bohe- 
 mia, and Hungary. It is an abundant ore in Chili, Peru, 
 and Mexico, and also in Nevada, and at the Comstock Lode, 
 and at Ophir, and Mexican mines, in the Reese River and 
 Humboldt, and other regions; in Colorado and Idaho. It 1s 
 sometimes called black silver. 
 
 Polybasite is near stephanite in color, specific gravity, and composi- 
 tion, but contains some arsenic and copper, with 64 to 72°2 per cent. of 
 silver. The crystals are trimetric, and usually in tabular hexagonal 
 prisms, without distinct cleavage. G.—6,214. From Freiberg, Przi- 
 bram ; Mexico and Chili; the Reese mines in Nevada, and Idaho. 
 
 Miargyrite is an antimonial silver sulphide, containing but 36°5 per 
 cent. of silver, and having a dark cherry-red streak, though iron-black 
 in color. B.B. on charcoal gives off fumes of antimony and an odor 
 of sulphur ; and in the oxidating flame, a globule is left which finally 
 yields a button of pure silver. 
 
 Brongniardite occurs in regular octahedrons and massive, erayish- 
 black in color, and contains about 25 per cent. of silver, with lead, an- 
 timony, and sulphur. G.=5-95. From Mexico. 
 
 Polyargyrite also is isometric, having cubic cleavage, and is from 
 Wolfach in Baden. It is near polybasite in composition=12Ag, 8+ 
 Sb, 8s. 
 
 Freieslebenite is a monoclinic antimonial silver-and-lead sulphide, of 
 a light steel-gray color, with G.=6-6:4. Contains 22 to 24 per cent. 
 of silver. From Saxony, Transylvania, and Spain. 
 
 Pyrostilpnite is another monoclinic silver ore ; its delicate crystals 
 are grouped like stilbite and have a fire-red color. Contains 62°3 per 
 cent. of silver. From Freiberg, Andreasberg, and Przibram. 
 
 Cerargyrite.—Horn Silver. Silver Chloride. 
 
 Isometric. In cubes, with no distinct cleavage. Also 
 massive, and rarely columnar; often incrusting. Color 
 gray, passing into green and blue; looks somewhat like horn 
 or wax, and cuts like it. Lustre resinous, passing into ada- 
 mantine. Streak shining. ‘Translucent to nearly opaque. 
 
 Composition. Ag Cl=Chlorine 24:7, silver 75°3. Fuses 
 in the flame of a candle, and emits acrid fumes. B.B. af- 
 fords silver easily on charcoal. The surface of a plate of 
 iron rubbed with it is silvered. 
 
 Obs. A very common ore and extensively worked in the 
 mines of South America and Mexico, where it occurs with 
 native silver ; and also abundant in Nevada about Austin, 
 Lander Co. ; in Idaho at Poor Man’s Lode ; occurs also in 
 Comstock Lode; and in Arizona; also at the mines of Sax- 
 ony, Siberia, Norway, the Hartz, and Cornwall. 
 
SILVER. Ter 
 
 Bromyrite or Bromie Silver. Silver united with bromine. Ag Br= 
 Bromine 42°6, silver 57°-4=100. Occurs with the preceding in Mexico 
 and Chili. 
 
 Embolite. A chlorobromide of silver, resembling the chloride or horn 
 silver. Color asparagus to olive green. Contains 51 of chloride of sil- 
 ver, to 49 of bromide. This ore is not less common in Chili than the 
 chloride. It has also been found in Chihuahua, Mexico. 
 
 Iodyrite. A silver iodide, Ag I=TIodine 54:0, silver 46-°0=100. It 
 has a bright yellow color. From Spain, Chili, Mexico, and the Cerro 
 Colorado Mine in Arizona. 
 
 Tocornalite. A silver-and-mercury iodide from Chili. 
 
 General Remarks.—The chief sources of the silver of commerce are 
 (1) Native silver ; (2) the sulphide, Argentite (or vitreous silver), com- 
 mon in Mexico, and also in the Humboldt, Reese River mining dis- 
 tricts ; four species among the sulpharsenites and sulphantimonites, 
 viz., (3) Proustite or the light red or ruby silver ore, and (4) Pyrar- 
 gyrite, or dark red silver ore, both common in Chilian, Peruvian, 
 and Mexican mines; (5) Freieslebenite ; (6) Argentiferous tetrahedrite, 
 which contains sometimes 10 to 80 per cent. of silver, abundant at 
 some Humboldt County, Nevada, mines, at Colorado silver mines, and 
 at various Chilian, Bolivian and Mexican mines, as well as in some 
 silver mines of Europe ; (7) Stephanite or brittle silver ore, common in 
 Nevada, Colorado, and at the Washoe mines, Western Utah ; (8) the 
 chloride, called horn-silver or Cerargyrite, common in Chili, Mexico, 
 Idaho; (9) the bromide and chlorobromide, Bromyrite and Hmbo- 
 lite, common in Chili and Mexico, especially the latter, along with 
 the rarer iodide; (10) Argentiferous Galenite, the lead ore, galenite, 
 even when containing but 5 ounces of silver to the ton, being profita- 
 bly worked for its silver. The other ores of silver mentioned beyond 
 are seldom of great abundance. The most important of them are sil- 
 ver amalgam or Arquerite, common especially in Chili, and Polybasite. 
 
 Silver ores occur in rocks of various ages, in gneiss and allied rocks, 
 in porphyry, trap, sandstone, limestone, and shales; and the sand- 
 stone and shales may be as recent as the Tertiary. The veins often 
 intersect trachytic, porphyry, and other eruptive rocks, or the sedi- 
 mentary formations in the vicinity of such rocks, and have owed their 
 existence in many cases to the heat, fracturing, and vapors from 
 below, attending the eruptions. 
 
 Silver ores are associated often with ores of lead, zinc, copper, co- 
 balt, and antimony, and the usual gangue is calcite or quartz, with 
 frequently fluor spar, pearl spar, or heavy spar. 
 
 The silver of South America is derived principally from the horn 
 silvers, stephanite, ruby silver, vitreous silver ore, and native silver. 
 Those of Mexico are of nearly the same character. Besides, there are 
 earthy ores called colorados, and in Peru pacos, which are mostly 
 earthy oxide of iron, with a little disseminated silver ; they are found 
 near the surface where the rock has undergone partial decomposition. 
 The sulphides of lead, iron, and copper of the mining regions, gene- 
 rally contain silver, and are also worked. 
 
 In South America the Chilian mines are on the western slope of the 
 Cordilleras, and are connected mostly with stratified deposits, of a 
 shaly, sandstone, or conglomerate character, and their intersections 
 
123 DESCRIPTIONS OF MINERALS. 
 
 with porphyries. The chlorides and native amalgams are found in 
 regions more toward the coast, while the sulphides and antimonial 
 ores abound nearer the Cordilleras. The richest mines are not far dis- 
 tant from Copiapo, in the mountains north of the valley of Huasco. 
 The mines of Mt. Chanarcillo, about 16 leagues south of Copiapo, 
 abound in horn silver, and begin to yield arsenio-sulphides at a depth 
 of about 500 feet. The mines of Punta Brava, which are nearer the 
 Cordilleras, afford the arsenical and antimonial ores. 
 
 In Peru, the principal mines are in the districts of Pasco, Chota, and 
 Huantaya. Those of Pasco are 15,700 feet above the sea, while those 
 of Huantaya are in a low desert plain, near the port of Yquique, in the 
 southern part of Peru. The ores afforded are the same as in Chili. 
 The mines of Huantaya are noted for the large masses of native silver 
 they have afforded. Silver is obtained in Peru, also, in the districts of 
 Caxamarca, Pataz, Huamanchuco, and Hualgayoc. 
 
 The Potosi mines in Bolivia, occur in a mountain of argillaceous 
 shale, whose summit is covered by a bed of argillaceous porphyry. 
 The ore is the ruby silver, and argentite with native silver. The dis- 
 trict of Caracoles, between Chili and Bolivia, yields much silver. 
 
 In Europe the principal mines are those of Spain, the province of 
 Guadalajara, where the ore is chiefly freieslebenite ; of Kongsberg in 
 Norway ; of Saxony, chiefly at Freiberg ; the Hartz; in Austria, Hun- 
 gary, Transylvania, and the Banat ; and Russia. The minesof Kongs- 
 berg occur in gneiss and hornblende slate, in a gangue of calc spar. 
 They were especially rich in native silver. 
 
 The mines of Saxony occur mostly in gneiss, in the vicinity of Frei- 
 
 berg, Ehrenfriedensdorf, J ohanngeorgenstadt, Annaberg, and Schnee- 
 berg. 
 The ores of the Hartz are mostly argentiferous copper pyrites and 
 galena, yet the ruby silver, argentite, stephanite, occur, especially at 
 ‘Andreaskreutz, and the mines of that vicinity. The rock intersected 
 by the deposits is mostly an argillaceous shale. Calcite is the usual 
 gangue, though it is sometimes quartz. 
 
 In the Tyrol, Austria, argentite, argentiferous tetrahedrite, and mis- 
 pickel occur in a gangue of quartz, in argillaceous schist. The Hun- 
 garian mines at Schemnitz and Kremnitz, occur in syenyte and horn- 
 blende porphyry, in a gangue of quartz, often with calcite or barite 
 (heavy spar), and sometimes fluorite. The ores are argentite. tetrahe- 
 drite, galena, blende, pyritous copper and iron; and the galena and 
 copper ores are argentiferous. France produces some silver from ar- 
 gentiferous galena at Huelgoet in Brittany, and the mines of Pontgi- 
 baud, Puy-de-Dome. 
 
 The Russian mines are in Kolyvan in the Altai, and Nertchinsk in 
 the Daouria Mountains, Siberia (east of Lake Baikal), The Daouria 
 mines afford an argentiferous galena which is worked for its silver ; 
 it occurs in a crystalline limestone. The silver ores of the Altai occur 
 in Silurian schists in the vicinity of porphyry, which contain also 
 gold, copper, and lead ores. 
 
 The mines of Mexico are most abundant between 18° and 24° north 
 latitude, on the back or sides of the Cordilleras, and especially the 
 west side ; and the principal are those of the districts of Guanaxuato. 
 Zacatecas, Fresnillo, Sombrerete, Catorce, Oaxaca, Pachuca, Real del 
 Monte, Batopilas, and Tasco, ‘The veins traverse very different rocks 
 
SILVER. 123 
 
 in these regions. The vein of Guanaxuato, the most productive in 
 Mexico, intersects argillaceous and chloritic shale, and porphyry ; it 
 affords one-forth of all the Mexican silver. The Valencian mine is 
 the richest in Guanaxuato. The Pachuca, Real del Monte, and Moro 
 districts, are near one another. Four great parallel veins tranverse 
 these districts, through porphyry. 
 
 In the United States the chief silver mines are in California, Ne- 
 vada, Colorado, Utah, Montana, and Idaho, The principal California 
 mines are in its southeastern counties bordering on Nevada, namely: 
 Alpine, Mono, and Inyo ; the total yield in 1874, about $1,700,000. 
 Those of Nevada are the Washoe region, about Virginia City and the 
 Comstock Lode; in Lander County, along Reese River Valley, etc., 
 the chief town of which is Austin; Esmeralda County, southeast of 
 Washoe ; in Eureka County, next east of Lander ; in Lincoln County, 
 the southeastern of the State ; Humboldt County to the north ; White 
 Pine, Nye and Elko counties, east and southeast of Lander County. 
 The rocks connected with the veins in Eastern California and Western 
 Nevada are eruptive rocks, related for the most part to andesyte (in 
 part, named propylite) and trachyte, with some doleryte. ‘The mines 
 of Utah, are those of the Big and Little Cottonwood districts (which 
 include the Emma Mine), the American Fork district, the Parley’s 
 Park district in the Wahsatch Range north of Big Cottonwood, and 
 the East Tintic district, in which are the Eureka Hill mines ; those 
 of Arizona, the Heintzelman, etc.; of Colorado, in the San Juan region; 
 of Northern Michigan, at the copper mines ; of Canada, at Prince’s 
 Mine, Spar Island, Lake Superior. 
 
 For the years previous to 1859 the whole yield of silver from United 
 States mines is estimated at $1,000,000. The following are the amounts 
 for the succeeding years, as published in Jones’s Senate Report (1877), 
 those for the years 1871 to 1876, inclusive, being from estimates by 
 J. J. Valentine. 
 
 Leaks Seated Vie $100,000 TOG cosa atex eects os Ee, 000,000 
 TRB Me eh wea eee. 150,000 SECU UES dee ere Foeee ce 13,000,000 
 ay Kins cia eK few os 2,100,000 gail) een Oaneanee Sree ee 17,320,000 
 Ee De ete io ste x a0 /s s 4,500,000 LO tlie tts yao ete © 19,286,000 
 EL a ie eee aa Re 8,500,000 TDi ees ha dese ee hs 19,924,429 
 bl 9 ieee an ear meme 11,000,000 se ieee gee ge es 27,483,802 
 ee teristics are, 2,> 11,250,000 Nis fc vung Ae eee Oe 29,699,122 
 [ee A A eee 10,000,000 pe. Be yt en ee ee 31,635,289 
 12 7 OR ee ae 13,550,000 A AG vale ene lg coe ts ere 39,292,924 
 
 The Comstock Lode contributed to the silver of the world first in 1861. 
 In 1875 it yielded $14,492,350, and the rest of Nevada $6,717,686= 
 
 21,209,986 ; and in 1876 these amounts were 90,570,078 and 7,462,752 
 — $28,032,830. The $7,462,752 from the “‘ rest of Nevada”’ in 1876, 
 were divided, as follows, between its principal mining regions : Lan- 
 der County, Austin district, $1,187,500 ; Esmeralda County, Columbus 
 district, $1,624,789 ; Elko County, Cornucopia district, $460,048 ; Eu- 
 reka County, $1,480,558 ; Lincoln County, Pioche or Ely district, 
 $790,095 ; Nye County, Tyboe and Reveille districts, $1,450,000. 
 
 The yield in 1876 of Utah was $8,351,520; of Colorado, 3,000,000 ; 
 of California, 1,800,000; of Arizona, 500,000 ; of Montana, 800,000 ; 
 of Idaho, 300,000 ; of New Mexico, 400,000, 
 
124 DESCRIPTIONS OF MINERALS. 
 
 In the “ Elements of Metallurgy,” of J. Arthur Phillips, the yield 
 for 1872 is given approximately, as follows : 
 
 
 
 Lbs. Troy. 
 Great Britain. ......-.e.e cece ee eee eeese 52,400 
 Norway and Sweden. ......-..+-.+ss500° 15,000 
 Hungary, Transylvania, and the Banat... 92,000 
 Gaxony....-seeeveceees 80,000 
 Parag te ccs eee eke 27500 hala! al.'s ee 178,000 
 Rest of Germany.....-. 60,500 
 Russias. ede d cos vibe tee Se Ae Sage eee 50,000 
 France . ook. pees bh bitkw Se Oe ee 16,500 
 Ttaly. 20 oe Be -a e 32,000 
 Spain. 2/25... vl. eel Rl ta ene 100,000 
 Pera? ee GA DORR SRL, Pi 200,000 
 Bolivia. oo bbe ees + ee ea ee 450,000 
 Ci ae ok OO a ee 800,000 
 Central America .........---2e2 eset eeeee 538,000 
 Mexico 2h. PINS 22 ie See 1,000,000 
 United States.) 020.6. 024 ee es 2 1,250,000 
 Total OIG aed 3,788,900 
 
 Mr. Phillips states that the total for the year probably amounted to 
 4,100,000 lbs. troy, the value of which is £13,000,000, or $63,000,000. 
 In the above the amount from the United States is diminished to make 
 it correspond with the preceding statement for 1872. 
 
 The following table gives, in dollars, the estimated value of the 
 world’s production of silver in recent years : 
 
 
 
 ——— 
 
 Mexico and 
 
 South America Other Countries. 
 
 Russia. United States. 
 
 eae 
 
 
 
 ——_ 
 
 1855 | 600,000 | .......--- 30,000,000 10,000,000=40,600,000 
 1860 | 650,000 150,000 | 80,000,000 10,000,000 =40,800,000 
 1865 | 700,000 | 11,250,000 30,000,000 10,000,000=51,950,000 
 1870 | 575,000 | 17,320,000 | 25,000,000 10,000,000 =57,895,000 
 1875 | 500,000 | 31,635,000 25,000,000 10,000,000 =67 135,000 
 
 —— ne 
 
 The total for 1876 is estimated at 76 millions. 
 
 The world’s production of silver for the period of twenty-six years, 
 from 1852 to 1877, is estimated at @1,341,800,000 ; for the preceding 
 twenty-two years—from 1830 to 1851, inclusive—at 600,400,000 ; for 
 the preceding thirty years—from 1800 to 1830—at $799,100,000. 
 
 
 
 
 
 
 
 
 
 Native Platinum. 
 Isometric : but crystals seldom observed. Usually in flat- 
 
 tened or angular grains or irregular masses. Cleavage none. 
 Color and streak pale or dark steel-gray. Lustre metallic, 
 
PLATINUM. 125 
 
 shining. Ductile and malleable. ~ H.=4-4°5." G.=16-19 ; 
 17-108, small grains ; 17-608, a mass. » Often slightly mag- 
 netic, and some masses will take up iron filings. | 
 
 Composition. Platinum is usually combined with more 
 or less of the rare metals iridium, rhodium, palladium, and 
 osmium, besides copper and iron, which give it a darker 
 color than belongs to the pure metal, and increase its hard- 
 ness. A Russian specimen afforded, Platinum 78-9, iri- 
 dium 5:0, osmium and iridium 1°9, rhodium 0°9, palladium 
 0:3, copper 0°7, iron 11°0=98°%5. nee 
 ~ Platinum is soluble in heated aqua regia. It is one of the 
 most infusible substances known, being wholly unaltered 
 before the blowpipe. It is very slightly magnetic, and this 
 quality is increased by the iron it may contain. 
 
 Diff. Platinum is at once distinguished by its ma lleability 
 and extreme infusibility. | j 
 
 Obs. Platinum was first detected in 1735 in grains in 
 the alluvial deposits of Choco and Barbagoa in New Granada 
 (now U. States of Colombia), within two miles of the north- 
 west coast of South America, where it received the name 
 
 latina, derived from the word plata, meaning silver. Al- 
 though before known, an account by Ulloa, a Spanish 
 traveler in America in 1735, directed attention in Europe, 
 jn 1748, to the metal. It is now obtained in Novita, and 
 at Santa Rita, and Santa Lucia, Brazil. It has been afforded 
 most abundantly by the Urals. It occurs also on Borneo ; in 
 the sands of the Rhine; in those of the river Jocky, St. 
 Domingo ; in traces in the United States, in North Carolina ; 
 at La Fran¢ois Beauce, Canada ; and with gold near Point 
 Orford, on the coast of Northern California (probably de- 
 rived, according to W. P. Blake, from serpentine rocks) ; in 
 British Columbia. 
 
 The Ural localities of Nischne Tagilsk and Goroblagodat 
 have afforded much the larger part of the platinum of com- 
 merce. It occurs, as elsewhere, in alluvial beds ; but the 
 courses of platiniferous alluvium have been traced to a great 
 extent up Mount La Martiane, which consists of crystalline 
 rocks, and is the origin of the detritus. One to ¢hree pounds 
 are procured from 3,700 pounds of sand. | 
 
 Though commonly in small grains, masses of considerable 
 size have occasionally been found. A mass weighing 1,088 
 grains was brought by Humboldt from South America and 
 deposited in the Berlin Museum. Its specific gravity was 
 
126 DESCRIPTIONS OF MINERALS. 
 
 18:94. In the year 1822, a mass from Condoto was de- 
 posited in the Madrid Museum, measuring 2 inches and 4 
 lines in diameter, and weighing 11,641 grains. A more 
 remarkable specimen was found in the year 1827 in the 
 Urals, not far from the Demidoff mines, which weighed 113 
 (more accurately, 11°57) pounds troy ; and similar masses 
 are now not uncommon. ‘The largest yet discovered weighed 
 21 pounds troy ; it is in the Demidoff cabinet. 
 
 Russia affords annually about 35 cwt. of platinum, which 
 is about five times the amount from Brazil, Borneo, Colom- 
 bia, and St. Domingo. Borneo affords about 500 pounds 
 per year. 
 
 The North Carolina platinum was found with gold in 
 Rutherford County. It was a single reniform granule, weigh- 
 ing 2°54 grains. Other instances are reported from the 
 Southern gold region. 
 
 The infusibility of platinum and its resistance to the 
 action of the air, and moisture, and most chemical agents, 
 renders it of great value for the construction of chemical 
 and philosophical apparatus. The large stills employed in 
 the concentration of sulphuric acid are now made of plati- 
 num; but such stills are gilt within, since platinum when 
 unprotected is acted upon by the acid, and soon becomes 
 porous. It is also used for crucibles and capsules in chemi- 
 cal analysis ; for galvanic batteries ; as foil, or worked into 
 cups or forceps, for supporting objects before the blowpipe. 
 It alloys readily when heated with iron, lead, and several of 
 the metals, and is also attacked by caustic potash and phos- 
 phoric acid, in contact with carbon ; and consequently there 
 should be caution when heating it not to expose it to these 
 ~ agents. 
 
 It is employed for coating copper and brass ; also for 
 painting porcelain and giving it a steel lustre, formerly 
 highly prized. It admits of being drawn into wire of ex- 
 treme tenuity. 
 
 Platinum was formally coined in Russia. The coins had 
 the value of 11 and 22 rubles each. 
 
 This metal fuses readily before the ‘‘compound blow- 
 pipe ;” and Dr. Hare succeeded in 1837 in melting twenty- 
 eight ounces into one mass. ‘The metal was almost as malle- 
 able and as good for working as that obtained by the other 
 process ; it had a specific gravity of 19°8. He afterwards 
 succeeded in obtaining from the ore masses which were 90 
 
PALLADIUM, 17 
 
 per cent. platinum, and as malleable as the metal in ordi- 
 nary use, though somewhat more liable to tarnish, owing to 
 some of its impurities. Deville and Debray have perfected 
 this process, and have melted over 25 pounds of platinum 
 in less than three-quarters of an hour. In the process the 
 osmium present is oxidized and thus removed. 
 
 Platin-iridium. Grains of iridium have been obtained at Nischne 
 Tagilsk, consisting of 76°8 iridium, and 19:64 platinum, with some 
 palladium and copper. A similar platin-iridium has been obtained at 
 Ava, in the East Indies. Another, from Brazil, contained 27°8 iridium, 
 55°5 platinum, and 6°9 of rhodium. 
 
 Tridosmine. A compound of iridium and osmium from the platinum 
 mines of Russia, South America, the East Indies, and California. The 
 crystals are pale steel-gray hexagonal prisms ; usually in flat grains. 
 H.=6°7. G.=19:5-21:1. Malleable with difficulty. 
 
 The composition varies. One variety, called Newjanskite, contains 
 iridium 46°8, osmium 49°38, rhodium 3:2, iron 0°7. Another, Sisser- 
 skite, iridium 25°1, osmium 74°9, and iridium 20, osmium 80. But 
 analysis affords also from 0°5 to 12°3 of rhodium, and 0:2 to 64 
 of the rarer metal ruthenium, with traces usually of platinum, cop- 
 per andiron. The grains are distinguished by their superior hardness 
 from those of platinum, and also by the peculiar odor of osmium when 
 heated with nitre. Iridosmine is common with the gold of Northern 
 California, and injures its quality for jewelry. Occurs sparingly in 
 the gold washings on the rivers Du Loup and Des Plantes, Canada. 
 
 The metal iridium is extremely hard, and is used, as well as rho- 
 dium, for points to the nibs of gold pens. Its specific gravity is 21°8. 
 
 Laurite. In minute octahedrons. A ruthenium sulphide, with 3 
 percent. of osmium. From platinum sands of Borneo and Oregon. 
 
 Palladium. 
 
 Isometric. In minute octahedrons. Occurs mostly in 
 grains, sometimes composed of divergent fibres. Color 
 steel-gray, inclining to silver-white. Ductile and malleable. 
 H. 4°5-5. G.=11°3~12°2. nt 
 
 Consists of palladium, with some platinum and iridium. 
 Fuses with sulphur, but not alone. 
 
 Obs. Occurs in Brazil with gold, and is distinguished 
 from platinum, with which it is associated, by the divergent 
 structure of its grains. It was discovered by Wollaston, in 
 1803. Selenpalladite, or Allopalladium, is native palladium 
 in hexagonal tables from Tilkerode in the Hartz. It is re- 
 ported also from St. Domingo and the Urals. Porpezile 
 is palladium gold, or gold containing about 10 per cent. of 
 palladium ; three samples assayed at the Rio de Janeiro 
 mint yielding 11-1, 9°75, and 7-7 per cent. of palladium. 
 
 
 
128 DESCRIPTIONS OF MINERALS. 
 
 This metal is malleable, and when polished. has a whitish 
 steel-like lustre which does not tarnish. A cup weighing 
 34 pounds was made by M. Breant in the mint at Paris, and 
 is now in the garde-meuble of the French crown. In hard- 
 ness it is equal to fine steel. 1 part fused with 6 of gold 
 forms a white alloy ; and this compound was employed, at 
 the suggestion of Dr. Wollaston, for the graduated part of 
 the mural circle constructed by Troughton for the Royal 
 Observatory at Greenwich. Palladium has been employed 
 also for certain surgical instruments. 
 
 MERCURY. 
 
 Mercury occurs native; alloyed with silver forming na- 
 tive amalgam; and in combination with sulphur, selenium, 
 chlorine, or iodine, and with sulphur and antimony in some 
 tetrahedrite. Its ores are completely volatile, excepting 
 when silver or copper is present. 
 
 Native Mercury, 
 
 Isometric. Occurs in fluid globules scattered through the 
 gangue. Color tin-white. G.=—13-56. Becomes solid and 
 crystallizes at a temperature of —39° F. 
 
 Mercury, or quicksilver, as it is often called (a translation 
 of the old name “‘argentum vivum),” is entirely volatile 
 before the blowpipe, and dissolves readily in nitric acid. 
 
 Obs. Native mercury is a rare mineral, yet is met with 
 at the different mines of this metal, at Almaden in Spain, 
 Idria in Carniola (Austria), in Hungary, Peru, and in Cali- 
 fornia. It is usually in disseminated globules, but is some- 
 times accumulated ‘in cavities so as to be dipped up in 
 pails. 
 
 Mercury is used for the extraction of gold and silver ores. 
 It is also employed for silvering mirrors, for thermometers 
 and barometers, and for various purposes connected with 
 medicine and the arts. 
 
 Native Amalgam. See page 117. 
 
 Cinnabar.—Mercury Sulphide. 
 Rhombohedral. RAR=%2° 86. Cleavage lateral, high- 
 
 ly perfect. Crystals often tabular, or six-sided prisms. Also 
 massive ; sometimes in earthy coatings. 
 
SILVER. 129 
 
 Lustre unmetallic, of crystals adamantine; often dull. 
 Color bright red to brownish red, and brownish black. 
 Streak scarlet-red. Subtransparent to nearly opaque. H. = 
 2-2°5. G.=85-9. Sectile. 
 
 Composition. Hg 8,=Sulphur 13°8, mercury 86°2. It 
 often contains impurities. The diver ore, or hepatic cinna- 
 bar, contains some carbon and clay, and has a brownish 
 streak and color. The pure variety volatilizes entirely be- 
 fore the blowpipe. 
 
 Diff. Distinguished from red oxide of iron and chromate 
 of lead by vaporizing before the blowpipe ; from realgar by 
 giving off on charcoal no alliaceous fumes. 
 
 Obs. Cinnabar is the ore from which the principal part 
 of the mercury of commerce is obtained. It is when pure 
 identical with the pigment vermilion. It occurs mostly in 
 connection with siliceous, talcose and argillaceous slates, or 
 other stratified deposits, both the most ancient and those of 
 more recent date. The mineral is too volatile to be expected 
 in any abundance in proper igneous or crystalline rocks, yet 
 has been found sparingly in granite. 
 
 ‘The localities are mentioned beyond. 
 
 Metacinnabarite is the same compound with cinnabar, but differs in 
 crystallization ; it is from Redington Mine, Lake County, California. 
 
 Guadalcazarite, of Mexico, is HgS8 in which alittle of the sulphur 
 is replaced by selenium. 
 
 Calomel or Horn Quicksilver. A tough, sectile mercury chloride, of 
 a light yellowish or grayish color, and adamantine lustre, translucent 
 or subtranslucent, crystallizing in secondaries to a square prism. 
 H.=1-2. G.=6°48. It contains 15-1 per cent. of chlorine, and 84:9 
 of mercury. 
 
 Lodie Mercury. A reddish-brown ore, from Mexico. 
 
 Tiemannite. A dark steel-gray mercury selenide, from the Hartz, 
 and the vicinity of Clear Lake, California. 
 
 Coloradoite. A grayish black mercury telluride, with G.—8-627, 
 from the Keystone and Mountain Lion Mines, Colorado. (Genth.) 
 
 Magnolite. A mercurous tellurate, Hg O, Te, from Magnolia dis- 
 trict, Colorado. 
 
 General Remarks.—The following are the regions of the principal 
 mines of mercury. At Idria, in Austria (discovered in 1497), where 
 the ore is a dark bituminous cinnabar distributed through a blackish 
 shale or slate, containing some native mercury ; at Almaden, in Spain, 
 near the frontier of EKstremadura, in the province of La Mancha, in 
 argillaceous beds and grit rock, which are intersected by dikes of 
 ‘“‘black porphyry ” and granite—mines mentioned by Pliny as afford- 
 ing vermilion to the Greeks, 700 years before the Christian era; in 
 the Palatinate on the Rhine ; in Hungary; Sweden ; several points in 
 France ; Ripa, in Tuscany; in Shensi, in China; at Arqueros, in 
 
130 DESCRIPTIONS OF MINERALS. 
 
 Chili ; at Huanca Velica and some other points in Peru ; at St. Onofre 
 and other places in Mexico ; in California and Idaho. 
 
 The most noted of the California mines, New Almaden, is situated 
 in Mine Hill, Santa Clara County, south of San Francisco. The rocks 
 are altered Cretaceous slates, talcose in part, with beds of serpentine 
 either side, and associated also with beds of jasper or siliceous slate. 
 The New Idria mine is in Fresno County, in the Mt. Diablo Range, and 
 was discovered in 1855. The rocks are more or less altered silico- 
 argillaceous and siliceous slates and sandstones, and the cinnabar is 
 distributed irregularly through them ; between this and the Aurora 
 Mine on San Carlos (the highest peak of the Diablo Range, 4,977 feet), 
 there is much serpentine (in which is chromic iron) and siliceous rock 
 or slate. In Napa Valley, Napa County, north of San Francisco, there 
 are other valuable mines situated in rocks closely similar, as Whitney 
 states, to those affording quicksilver at New Almaden. They are in 
 a serpentine belt, the cinnabar being in some places in the serpentine, 
 but mostly in the peculiar siliceous rock associated with it. Native 
 mercury occurs with the cinnabar. 
 
 The product of the California mines of mercury in 1874, is given as 
 follows by Raymond, in his ‘‘ Mineral Resources for 180; 
 
 New Almaden........ Santa Clara County......- 9,084 flasks. 
 New Idria.........> +-0 Fresno MS Poet (00. 42* 
 Cerro Bonito.........- te beng 2 Pe scher acct" 11 OR ieee ~ 
 California (osc ss ee Napa Sah Oe ace 8,000 ** 
 Manhattan’s ... yaa as +f oi ae es 620. °° 
 Phone... aon chokes ms dae MEN NERO be 685 <“ 
 Washington.........- ie spe raalie Apne ps | aed 
 Redington? 77... 02.2 5 Lake dba ene Tea) wos 
 California Borax...... * salina ht) Me yb aera 
 Great Western........ ze 60S ae ee 1300. 
 Buckeye. ss 5.5 oss ee Colusa pane bg hie 08 700 tae 
 Missouri! so 2. coon Sonoma 8 ey eee 200 * 
 Oekiand. fo). ees A li EA PA el Bf uae 
 Sait DORM oe verte he Solano FEE Ns eee 1,900 ‘* 
 
 Which, with the additions from a few other less productive open- 
 ings, make a total of 34,254 flasks, or over 2,400,000 Ibs. The yield 
 in 1867 was 44,386 flasks, or about 3,400,000 lbs. The total yield of 
 the world in 1872, is stated by Phillips at 6,670,000 lbs. avoirdupois. 
 
 COPPER. 
 
 Copper occurs native in considerable quantities ; and also 
 combined with oxygen, sulphur, selenium, arsenic, anti- 
 mony, chlorine, and as carbonate, phosphate, arsenate, sul- 
 phate, and vanadate. The ores of copper vary in specific 
 gravity from 3°5 to 8°5, and seldom exceed 4 in hardness. 
 
ORES OF COPPER. 181 
 
 Native Copper. 
 
 Isometric. In octahedrons; no cleavage apparent. Often 
 in plates or masses, or arborescent and filiform shapes. 
 Color copper-red. Ductile and malleable. H.=2:5-3. 
 
 “84, 
 
 Native copper often contains a little silver disseminated 
 throughout it. Before the blowpipe it fuses readily, and on 
 cooling it is covered with a black oxyd. Dissolves in nitric 
 acid, and produces a deep azure-blue solution on the addition 
 of ammonia. 
 
 Obs. Native copper accompanies the ores of copper, and 
 usually occurs in the vicinity of dikes of igneous rocks. 
 
 Siberia, Cornwail, and Brazil are noted for the native cop- 
 per they have produced. A mass, supposed to be from Bahia, 
 now at Lisbon, weighs 2,616 pounds. South of Lake Supe- 
 rior about Portage Lake: on Keweenaw Point, and also, less 
 abundantly, on the Ontanagon River, and at some other 
 points in that region, native copper occurs mostly in veins 
 in trap, and also in the enclosing sandstone. A mass 
 weighing 3,704 Ibs. has been taken from thence to Wash- 
 ington City; it is the same that was figured by School- 
 craft, in the American Journal of Science, volume iil., p 
 201. One large mass was quarried out in the “ Cliff Mine,” 
 whose weight has been estimated at 200 tons. It was 40 
 feet long, 6 feet deep, and averaged 6 inches in thickness. 
 This copper contains, intimately mixed with it, about ', per 
 cent. of silver. Besides this, perfectly pure silver, in strings, 
 masses, and grains, is often disseminated through the cop- 
 per, and some masses, when polished, appear sprinkled with 
 large white spots of silver, resembling, as Dr. Jackson ob- 
 serves, a porphyry with its feldspar crystals. Crystals of 
 native copper are also found penetrating masses of prehnite 
 and analcite in the trap rock. This mixture of copper and 
 silver cannot be imitated by art, as the two metals form an 
 alloy when melted together. It is probable that the separa- 
 tion in the rocks is due to the cooling from fusion being 
 so extremely gradual as to allow the two metals to solidify 
 separately, at their respective temperatures of solidification— 
 the trap being an igneous rock, and ages often elapsing, as 
 is well known, during the cooling of a bed of lava, covered 
 from the air. Native copper occurs sparingly in St. Ignace 
 and Michipicoton Islands, Lake Superior, 
 
132 DESCRIPTIONS OF MINERALS, 
 
 Small specimens of native copper have been found in the 
 States of New Jersey, Connecticut,and Massachusetts, where 
 the Triassic formation occurs. One mass from near Somer- 
 ville, N. J., weighs 78 pounds, and is said originally to have 
 weighed 128 pounds. Within a few miles to the north of 
 New Haven, Conn., one mass of 90 pounds, and another of 
 200, besides other smaller, have been found in the drift, all 
 of which came from veins in the trap or associated Triassic 
 sandstone. Near New Brunswick, N. J., a vein or sheet of 
 copper, from a sixteenth to an eighth of an inch thick, has 
 been observed and traced along for several rods. 
 
 Native copper occurs also in South Australia ; it is stated 
 that a single train from the Moonta Mine carried away at 
 one time forty tons of native copper. 
 
 Chalcocite.—Copper Glance. Vitreous Copper Ore. Redruthite. 
 
 Trimetric. I: Z=119° 35’. Cleavage 
 parallel to 7, but indistinct. Also in com- 
 
 (| [1) pound crystals like aragonite. Often mas- 
 
 sive. 
 ) \$ Color and streak blackish lead-gray ; often 
 tarnished blue or green. Streak sometimes — 
 | shining. H.=2'5-3, G. =5°5-5'8. 
 
 Composition. Cu, S=Sulphur 20°2, cop- 
 \ / per 79°8=100. B.B. on charcoal gives off 
 NS, fumes of sulphur, fuses easily in the exte- 
 rior flame; and after the sulphur is driven 
 off, a globule of copper remains. Dissolves 
 
 in heated nitric acid, with a precipitation of the sulphur. 
 
 Diff. Resembles argentite, but it is not sectile, like that 
 ore, and they afford different results before the blowpipe. 
 The solution of the ore in nitric acid covers an iron plate 
 (or knife blade) with copper, while a similar solution of the 
 silver ore covers a copper plate with silver. 
 
 Obs. Occurs with other copper ores in beds and veins. 
 At Cornwall, splendid crystallizations occur. Siberia, Hesse, 
 Saxony, the Banat, Chili, etc., afford this ore. 
 
 In the United States, a vein affording fine crystallizations 
 occurs at Bristol, Conn. Other localities are at Wolcott- 
 ville, Simsbury, and Cheshire, Conn. 5 at Schuyler’s Mines, 
 and elsewhere, N. J. ; in the U. S. copper-mine district, 
 Blue Ridge, Orange County, Virginia; between New Market 
 and Taneytown, Maryland; and sparingly at the copper 
 
ORES OF COPPER. 133 
 
 mines of Michigan and the Western States; also at some 
 mines north of Lake Huron ; in the San Juan mining region, 
 Colorado; north of Gila-Riva, near the borders of New 
 Mexico and Arizona; at the Bruce Mines, Lake Huron, 
 and at Prince’s Mine, Spar Island, and on Michipicoton 
 Islands, Lake Superior. . 
 
 Covellite, or Blue Copper. A dull blue-black massive mineral, with 
 the composition CuS. G=8°8. It contains 66:5 per cent. of copper. 
 
 Harrisite. A copper glance with cubic cleavage, from Canton Mine, 
 Ga.; probably a pseudomorph after galenite. 
 
 Chalcopyrite.—Copper Pyrites. Copper-and-Iron Sulphide. 
 
 Dimetric. Crystals tetrahedral or 
 octahedral ; sometimes compound. 
 I X [=109° 53’, and 108° 40’. Cleav- 
 age indistinct. Also massive, and of 
 various imitative shapes. 
 
 Color brass-yellow, often tarnished 
 deep yellow, and also iridescent. 
 Streak unmetallic, greenish black, and 
 but little shining. H.=3-°5-4. G. 
 =4:15-4°3. 
 
 Composition. CuFe 8, = Sulphur 
 34:9, copper 34°6, iron 80°5=100. Fuses B.B. to a globule 
 which is magnetic, owing to the iron present. Gives sulphur 
 fumes on charcoal. With soda on charcoal affords a glo- 
 bule of metallic iron with copper. The usual effect with 
 nitric acid. 
 
 Diff. This ore resembles native gold, and also pyrite. It 
 is distinguished from gold by crumbling when it is attempted 
 to cut it, instead of separating in slices; and from pyrite in 
 its deeper yellow color, and in yielding easily to the point of 
 a knife, instead of striking fire with a steel. 
 
 Obs. Copper pyrites occurs in veins intersecting gneiss 
 and other metamorphic rocks ; also in those connected with 
 eruptive rocks ; and sometimes in cavities or veins in ordi- 
 nary stratified rocks. It is usually associated with pyrite, 
 and often with galenite, blende, and copper carbonates. The 
 copper of Fahlun, Sweden, is obtained mostly from this ore, 
 where it occurs with serpentine in gneiss. Other mines of 
 this ore are in the Hartz, near Goslar ; in the Banat, Hun- 
 gary, Thuringia, etc. The Cornwall ore is mostly of this 
 kind. As prepared for sale at Redruth it rarely yields 12 
 
 
 
134 DESCRIPTIONS OF MINERALS. 
 
 per cent., and generally only 7 or 8, and occasionally as little 
 as 3 to 4 per cent. of metal ; ‘64 per cent. of metal may be 
 considered an average of the produce of the total quantity of 
 ore sold.” (Phillips, 1874.) Such poverty of ore is only made 
 up by its facility of transport, the moderate expense of fuel, 
 or the convenience of smelting. Its richness may generally 
 be judged of from the color: if of a fine yellow hue, and 
 yielding readily to the hammer, it is a good ore; but if hard 
 and pale yellow it contains much pyrite, and 1s of poor 
 quality. 
 
 {n the United States there are many localities of this ore. 
 It occurs in mines in Vermont, at Strafford ; and at Shrews- 
 bury, Corinth, Waterbury ; also in New Hampshire, Maine, 
 Massachusetts, and Connecticut; in New York, at the Ancram | 
 lead mine; also near Rossie, and at Wurtzboro’; in Penn- 
 sylvania, at Morgantown ; in Virginia, at the Phenix copper 
 mines, Fauquier County, and at the Walton gold mine, 
 Luzerne County; in Maryland, in the vicinity of Liberty and 
 New London in Frederick County; and at the Patapsco 
 mines near Sykesville ; in North Carolina, in Davidson and 
 Guilford counties. In Michigan, where native copper 1s so 
 abundant, this is a rare ore; but it occurs at Presqu’isle, at 
 Mineral Point, and in Wisconsin, where it is the predomi- 
 nating ore ; in Tennessee, in Polk County, at the Hiwassee 
 mines; in the San Juan mining region, Colorado; in Lan- 
 der Co., and elsewhere, Nevada ; at Copperopolis, Calaveras 
 Co., California ; also at the Bruce and other mines on Lake 
 Huron ; and Michipicoton Islands, mm Lake Superior. 
 
 Cubanite is a copper-and-iron sulphide, containing Sulphur 89:0, 
 iron 38°0, copper 19°8, silica 2°3=99°12. 
 
 Bornite.—Erubescite. Variegated Copper Pyrites. 
 
 Isometric. Cleavage octahedral in traces. Occurs in oc- 
 tahedrons and dodecahedrons. Also massive. 
 
 Color between copper-red and pinchbeck-brown. Tar- 
 nishes rapidly on exposure. Streak pale grayish-black and 
 but slightly shining. Brittle. H.=3. G.=o. 
 
 Composition. Cu,Fe 8,=Sulphur 28°6, copper 55°58, iron 
 16°36 ; but varies much. 
 
 The ore of Bristol, Conn., afforded Sulphur 25°83, copper 
 61°79, iron 11°77=99°39. 
 
 B.B. on charcoal fuses to a brittle globule attractable by 
 
ORES OF COPPER. 135 
 
 the magnet; dissolves in nitric acid, with separation of 
 sulphur. 
 
 Diff. This ore is distinguished from the preceding by its 
 pale reddish-yellow color, and its rapidly tarnishing and 
 becoming of bluish and reddish shades ot color, the quality 
 to which the name erubescite, from the Latin word for to 
 blush, alludes. 
 
 Obs. Occurs, with other copper ores, in granitic and al- 
 lied rocks, and also in stratified formations. ‘The mines of 
 Cornwall have afforded crystallized specimens, and it is there 
 called, from its color, ‘‘ horse-flesh ore.” Other foreign 
 localities of massive varieties are Ross Island, Killarney, Ire- 
 land; Norway, Hessia, Silesia, Siberia, and the Banat. 
 
 Fine crystallizations were formerly obtained at the Bristol 
 copper mine, Conn., in granite ; and also in red sandstone, 
 at Cheshire, in the same State, with malachite and barite. 
 Massive varieties occur at the New Jersey mines, and in 
 Pennsylvania. 
 
 Crookesite. A copper selenide, containing 17°25 per cent. of thallium, 
 and a little silver. 
 
 Domeykite, Algodonite and Whiineyite are copper arsenides ; Ber- 
 zelianite, a copper selenide ; Hucairite, a copper-and-silver selenide. 
 
 Tennantite. A compound of copper, iron, sulphur, and arsenic. It 
 oceurs in dodecahedral crystals, brilliant, with a dark lead-gray color, 
 and reddish-gray streak. From the Cornish mines near Redruth and 
 St. Day in Cornwall. 
 
 Tetrahedrite.—Gray Copper. Fahlerz. 
 
 Isometric and tetrahedral. Occurs in tetrahedral forms. 
 Cleavage octahedral in traces. 
 
 Color between steel-gray and iron- 
 black. Streak nearly like the color, 
 sometimes inclined to brown and 
 cherry-red. Rather brittle. H.=3- 
 Ad, G.=4°5- 5°12. 
 
 Composition. Cu, 8, Sb, (= 4 Cu, 
 S+Sb, §,), but with part of the cop- 
 per replaced usually by iron and 
 zinc, and sometimes silver or quick- 
 silver, and part of the antimony by | 
 arsenic, and rarely bismuth. It sometimes contains 30 per 
 cent. of silver in place of part of the copper, and is then 
 called argentiferous tetrahedrite. ‘The amount of arsenic 
 varies from 0 to 10 per cent. One variety from Spain in- 
 cluded 10 per cent. of platinum, and another from Hohen- 
 
 
 
136 DESCRIPTIONS OF MINERALS, 
 
 stein some gold. Specimens from Schwatz, and some other 
 localities, contain 15 to 18 per cent. of mercury, and are 
 called Spaniolite. A kind containing 9 to 13 per cent. of 
 lead and 10 to 13 of silver, has been called Malinowskite. 
 
 Obs.. The Cornish mines, Andreasberg in the Hartz, 
 Kremnitz in Hungary, Freiberg in Saxony, Kapnik in Tran- 
 sylvania, and Dillenberg in Nassau, afford fine erystalliza- 
 tions of this ore. It isa common ore in the Chilian mines, 
 and it is worked there and elsewhere for copper and often 
 also for silver. Occurs also in Mexico; in Mariposa and 
 Shasta counties, Cal.; abundantly at the Sheba and De Soto 
 mines, Humboldt Co.; Nevada, near Austin in Lander Co. ; 
 in the San Juan region, Colorado; at the Heintzelman 
 Mine, and the Santa Rita Mine, in Arizona ; also in fine 
 erystallizations in the caves of Huallanca, on the Peruvian 
 Andes, at a height of about 14,700 feet, an ore yielding 
 much silver. 
 
 Bournonite. Contains Sulphur 29°6, antimony 25:0, lead 42°24, cop- 
 per 18°0=100. Its crystals are modified rectangular prisms, of a steel- 
 gray color and streak, and are often compounded into shapes like a 
 cog-wheel, whence it is called «wheel-ore. H.=2°5-3. G.=5°766. 
 From the Tyrol, Hartz, Transylvania, Saxony, Cornwall, and Siberia. 
 
 Other sulphantimonites or sulpharsenites of copper are Chalcostibite, 
 Emplectite, Binnite, Stylotypite, Aikinite, Enargite, Polybasite. Poly- 
 basite contains also silver. 
 
 Atacamite.—Copper Oxichloride. 
 
 Trimetric; in rhombic prisms and other forms; also 
 granular massive. Color green to blackish green. Lustre 
 adamantine to vitreous. Streak apple-green. . Translucent 
 to subtranslucent. H. = 3-35. G.=3°75-3°9. Com- 
 position, CuCl, +3 Cu O, H,=Chlorine 16°64, oxygen 11°25, 
 copper 11:25, water 12°66=100. From the Atacama desert, 
 between Chili and Peru, and elewhere in Chili; also from 
 Bolivia, Vesuvius, Saxony, Spain, Cornwall. 
 
 Cuprite.—Red Copper Ore. 
 
 Isometric. In regular octahedrons, and modified forms of 
 the same. Cleavage octahedral. Also massive, and some- 
 times earthy. 
 
 Color deep red, of various shades. Streak brownish red. 
 Lustre adamantine or submetallic; also earthy. Subtrans- 
 parent to nearly opaque. Brittle. H. = 3°5-4, G, =5d°8d- 
 6°15. 
 
 — 
 
ORES OF COPPER. 137 
 
 Composition. Cu, O=Oxygen 11:2, copper 88°38. B.B. 
 on charcoal, yields a globule of copper. Dissolves in nitric 
 as The earthy varieties have been called ¢i/e ore, from 
 the color. 
 
 Ox € 
 S&S © 
 
 Diff. From cinnabar it differs in not being volatile before 
 the blowpipe ; and from red iron ore in yielding a bead of 
 copper on charcoal, and copper reactions. 
 
 Obs. Occurs with other copper ores in the Banat, Thu- 
 ringia, Cornwall, at Chessy near Lyons, in Siberia, and Bra- 
 zil. The octahedrons are often green, from a coating of 
 malachite. 
 
 In the United States, it has been observed crystallized and 
 massive at Schuyler’s, Somerville, and the Flemington cop- 
 per mines, N. J.; also near New Brunswick, N. J.5 at 
 Bristol, Conn.; near Ladenton, Rockland County, N. Y.; in 
 the Lake Superior region. 
 
 Tenorite, Melaconite, or Black Copper. An oxide of cop- 
 per, CuO, occurring as a black powder, and in dull black 
 masses and botryoidal concretions, in veins or along with 
 other copper ores; also in iron-gray flexible scales, in the 
 Vesuvian lavas. It is an abundant ore in some of the cop- 
 per mines of the Mississippi Valley, and yields 60 to 70 per 
 cent. of copper. It results from the decomposition of the 
 sulphides and other ores. At the Hiwassee Mine, Polk Co., 
 Tennessee, it has been abundant. It was formerly found of 
 excellent quality in the Lake Superior copper region. 
 
 Chalcanthite.—Blue Vitriol. Sulphate of Copper. 
 
 Triclinic. In oblique rhomboidal prisms. Also as an 
 efflorescence or incrustation, and stalactitic. 
 
 Color deep sky-blue. Streak uncolored. Subtransparent 
 to translucent. Lustre vitreous. Soluble, taste nauseous 
 and metallic. H.=2-2°5. G.=2°21, 
 
138 DESCRIPTIONS OF MINERALS. 
 
 Composition. Cu O,8+5 aq=Sulphuriec acid (or sulphur 
 trioxide) 32-1, copper oxide 31°8, water 36:1. A polished 
 plate of iron in solutions becomes covered with copper. 
 
 Obs. Occurs with the sulphides of copper as a result of 
 their decomposition, and is often in solution in the waters 
 flowing from copper mines. Occursin the Hartz, at Fahlun 
 in Sweden, and in many other foreign copper regions; in 
 the Hiwassee copper mine, Tennessee; the Canton mine, 
 Georgia ; at Copiapo, Chili. 
 
 Blue vitriol is much used in dyeing operations and in the 
 printing of cotton and linen; also for various other pur- 
 poses in the arts. It has been employed to prevent dry rot, 
 by steeping wood in its solution: and it is a powerful pre- 
 servative of animal substances ; when imbued with it and 
 dried, they remain unaltered. It is afforded by the decom- 
 position of copper pyrites, in the same manner as green vit- 
 riol from iron pyrites ; but it is manufactured for the arts, 
 chiefly from old sheathing-copper, copper turnings, and cop- 
 per refinery scales. 
 
 In Frederick County, Maryland, blue vitriol is made from 
 a black earth which is an impure oxide of copper with cop- 
 per pyrites. 
 
 In some mines, the solution of sulphate of copper is so 
 abundant as to afford considerable copper, which is obtained 
 by immersing clean iron in it, and is called copper of cemen- 
 tution. At the copper springs. of Wicklow, Ireland, about 
 500 tons of iron were laid at one time in the pits ; in about 
 12 months the bars were dissolved, and every ton of iron 
 yielded a ton and a half, and sometimes nearly two tons, of 
 a precipitated reddish mud, each ton of which produced 16 
 ewt. of pure copper. The Rio Tinto Mine in Spain is an- 
 other instance of working the sulphate in solution. These 
 waters yield annually 1,800 cwt. of copper, and consume 
 2,400 cwt. of iron. 
 
 Brochantite. An insoluble copper sulphate, containing 17°7 per 
 cent. of sulphur trioxide. Color emerald-green, In tabular rhombic 
 crystals, from the Urals, Retzbanya, Cornwall, Mexico, Chili, Aus- 
 tralia. Krisuvigite and Konigite are the same species. 
 
 Langite, Cyanotrichite (Velvet copper ore), Krénkite, Philippite, 
 Enysite, Linarite, Dolerophanite, Hydrocyanite, are other sulphates 
 containing copper, the last two anhydrous; and OConnellite is another 
 containing chlorine, from Cornwall. 
 
 The Copper tungstate, Cuprotungstite, occurs of a yellowish-green 
 color in Chili. 
 
 \ 
 
ORES OF COPPER. 139 
 
 Olivenite.—Hydrous Copper Arsenate. 
 
 Trimetric. ZAJ=92° 30’. In prismatic crystals, and 
 also fibrous and granular massive. Olive-green, and of 
 other greenish shades, to liver and wood-brown. Streak 
 olive-green to brown. Substransparent to opaque. Brittle. 
 Pieeeoe Gr. 4°] —4"4, 7 
 
 Composition. Cu, O, As,= Arsenic pentoxide 40°66, copper 
 oxide 56°15, water 3:19=100. Fuses very easily, coloring 
 the flame bluish green. B.B. fuses with deflagration, giv- 
 ing off arsenical fumes, and affords a brittle globule, which 
 with soda yields metallic copper. 
 
 Obs. From Cornwall, the Tyrol, Siberia, Chili, and other 
 places. 
 
 Besides the above, there are the following salts of copper + 
 
 Copper Arsenates.—Huchroite has a bright emerald-green color, and 
 contains 33 per cent. o” arsenic acid, and 48 of oxide of copper ; occurs in 
 modified rhombic prisms ; H.=3°70 ; G=3'4; from Libethen, in Hun- 
 gary. Olinoclasite (Aphanesite) is ofa dark verdigris-green inclining to © 
 blue, and also dark blue; H. =2'5-3; G. —4:-19-4°36. It contains 62°7 per 
 cent. of copper oxide ; from Cornwall. Hrinite has an emerald-green 
 color, and occursin mammillated coatings ; H.—4'5-5; G.=—4°04; con- 
 tains 59:4 per cent. of copper oxide ; from Limerick, Ireland. Lrroco- 
 nite varies from sky-blue to verdigris-green ; occurs in rhombic prisms, 
 sometimes an inch broad; H.=2-2°5; G.=2°8-2°98. Chalcophyllit? 
 (copper mica) is remarkable for its thin foliated or mica-like structure ; 
 color emerald or grass-green ; H.=2; G.=2°55. Contains 58 per cent- 
 of copper oxide; from Cornwall and Hungary. Tyrolite (Copper 
 froth) is another arsenate of a pale apple-green and verdigris-green 
 color; it has a perfect cleavage ; it contains 43°9 per cent. of copper 
 oxide ; from Hungary, Siberia, the Tyrol, and Derbyshire. Cornacall- 
 ste and Chlorotile, are names of other copper arsenates. These dif- 
 ferent arsenates of copper give an alliaceous odor when heated on 
 charcoal before the blowpipe. 
 
 Copper Phosphates.—Pseudomalachite (Phosphochalcite, Ehlite, Di 
 hydrite) occurs in very oblique crystals, or massive and incrusting, and 
 has an emerald or blackish-green color; H.=4'5-5 ; G.=4°34 ; contains 
 64 to 70 per cent. of copper oxide ; from near Bonn, on the Rhine, and 
 also from Hungary. Jibethenite has a dark or olive-green color, and 
 occurs in crystals, usually octahedral in aspect, and massive ; H.= 
 4; G.=8'6-8°8 ; contains 66:5 per cent. of oxide of copper ; from 
 Hungary and Cornwall. Other copper phosphates are Veszelyite, 
 Tagilite, Isoclasite. Torbernite is a copper-and-uranium phosphate. 
 These phosphates give no fumes before the blowpipe, and have the 
 reaction of phosphoric acid. 
 
 Copper Vanadates.— Volborthite is a copper-and-calcium vanadate 
 from the Urals; and Mottrammite and Psittacinite, copper-and-lead 
 yanadates, the former from England, and the latter from gold mines 
 in Silver Star district, Montana. 
 
 Rivotite. Yellowish-green copper antimonate and carbonate, 
 
140 DESCRIPTIONS OF MINERALS. 
 
 Malachite.—Green Copper Carbonate. 
 
 Monoclinic. Usual in incrustations, with a smooth tube- 
 rose, botryoidal, or stalactitic surface ; structure finely and 
 firmly fibrous. Also earthy. 
 
 Color light green, streak paler. Usually nearly opaque ; 
 crystals translucent. Lustre of crystals adamantine inclin- 
 ing to vitreous; but fibrous incrustations silky on a cross 
 fracture. Earthy varieties dull. H.=3°5-4. G.=3-7-4, 
 
 Composition. Cu, O,C+H, O=Carbon dioxide (or car- 
 bonic acid) 19:9, copper oxide 71:9, water 8:2=100. Dis- 
 solves with effervescence in nitric acid. 
 
 B.B. decrepitates and blackens, colors the flame green, 
 and becomes partly a black scoria. With borax it fuses to a 
 deep-green globule, and ultimately affords a bead of copper. 
 
 Diff. Readily distinguished by its copper-green color and 
 its associations with copper ores. It resembles a siliceous 
 ore of copper, chrysocolla, a common ore in the mines of the 
 Mississippi Valley; but it is distinguished by its complete so- 
 lution and effervescence in nitric acid. The color also is not 
 the bluish green of chrysocolla. 
 
 Obs. Green malachite usually accompanies other ores of 
 copper, and forms incrustations, which, when thick, have 
 the colors banded and delicate in their shades and blending. 
 Perfect crystals are quite rare. The mines of Siberia, at 
 Nischne Tagilsk, have afforded great quantities of this ore. 
 A mass, partly disclosed, measured at top 9 feet by 18; and 
 the portion uncovered contained at least half a million 
 pounds of pure malachite. Other noted foreign localities 
 are Chessy, in France; Sandlodge, in Shetland; Schwatz 
 in the Tyrol; Cornwall; the Island of Cuba; Serro do 
 ea ee west coast of Africa; copper mines of Australia ; 
 
 nil. 
 
 The copper mine of Cheshire, Conn., has afforded hand- 
 some specimens ; also Morgantown, Perkiomen, and Pheenix- 
 ville, Penn.; Schuyler’s Mine, and the New Brunswick 
 copper mine, N. J. ; it occurs also in Maryland, between 
 Newmarket and Taneytown ; and in the Catoctin Mountains ; 
 in the Blue Ridge, Penn., near Nicholson’s Gap ; also in 
 
 ntic district, Utah. 
 
 Ti At Mineral Point, Wisconsin, a bluish silico-carbonate of 
 ocpper occurs, which is for the most part chrysocolla, or a 
 mixture of this mineral with the carbonate. 
 
ORES OF COPPER. 141 
 
 This mineral receives a high polish and is used for tables, 
 mantelpieces, vases; and also ear-rings, snuff-boxes, and va- 
 rious ornamental articles. It is not much prized in jewelry. 
 At Versailles there is a room furnished with tables, vases, 
 and other articles of this kind ; and similar rooms are to be 
 found in many European palaces. 
 
 Malachite is sometimes passed off in jewelry as turquois, 
 though easily distinguished by its shade of color and much 
 inferior hardness. It is a valuable ore when abundant ; but 
 itis seldom smelted alone, because the metal is lable to es- 
 cape with tke liberated volatile ingredient. 
 
 Azurite.—Blue Copper Carbonate. Blue Malachite. 
 
 Monoclinic. In modified oblique rhombic prisms, the 
 crystals rather short and stout ; 
 lateral cleavage perfect. Also mas- 
 sive. Often earthy. 
 
 Color deep blue, azure blue, Ber- 
 lin blue. ‘Transparent to nearly 
 opaque. Streak bluish. Lustre 
 vitreous, almost adamantine. Brit- 
 tle. H.=—3°5-45. G.=3'5-3°85. 
 
 Composition. Cu, O,C,+H, O= 
 Carbon dioxide 25°6, copper oxide 
 69°2, water 5-2. B.B. and in acids like the preceding. 
 
 Obs. Azurite accompanies other ores of copper. Chessy, 
 France, has afforded fine crystals ; found also in Siberia; in 
 the Banat; near Redruth in Cornwall; at Phoenixville, Pa., 
 in crystals ; in Wisconsin near Mineral Point ; as incrusta- 
 tions, and rarely as crystals, near Sing Sing, N. Y.; near 
 New Brunswick, N. J.; near Nicholson’s Gap, in the Blue 
 Ridge, Pa. 
 
 When abundant it is a valuable ore of copper. It makes 
 a poor pigment as it is liable to turn green. 
 
 Aurichalcite (Buratite) is a hydrous copper-and-zinc carbonate, or a 
 cuprous hydrozincite, pale green to sky-blue in color ; from the Altai, 
 Retzbanya, Chessy in France, Tyrol, Spain, Leadhills in Scotland, and 
 Lancaster, Pa. 
 
 
 
 Dioptase.—Copper Silicate. 
 
 Rhombohedral. RAR=126° 24’. Occurs in six-sided 
 prisms with rhombohedral terminations. Color emerald- 
 green. Lustre vitreous. Transparent to nearly opaque. 
 H. 0. ey <3 28-3 D0. 
 
142 DESCRIPTIONS OF MINERALS. 
 
 Composition. Cul, 0,S8i=Silica 38-1. copper, oxide 50°4, 
 water 11°5—100. B.B. with soda on charcoal yields copper, 
 and this, with its hardness, distinguishes it from the spe- 
 cies it resembles. 
 
 Obs. From the Khirgeez Steppes of Siberia. 
 
 Chrysocolla.—Hydrous Copper Silicate. 
 
 Usually as incrustations ; botryoidal and massive. Also 
 in thin seams and stains; no fibrous or granular structure 
 apparent, nor any appearance of crystallization. 
 
 Color bright green, bluish green. Lustre of surface of 
 incrustations smoothly shining; also earthy. ‘Translucent 
 to opaque. H.=2-4. G.=2-2°4. 
 
 Composition. CuO, Si+2 aq=Silica 342, copper oxide 
 45°3, water 20°5=100. 
 
 SIBERIAN. NEW JERSEY. 
 Von Kobell. Berthier. Bowen. Beck. 
 Oxide of copper... 40°0 .......... 5B OS AO. ea 
 Siliea): Ae ewes a S65) 2 Brees Shed See eee 
 Waterco Gi. ecelet 90°2. os sow ab eo ERR eel ear ee 
 Carbonic acid...... Pf og. erm i gine sc omen, ye Ec ganar 
 * Oxide of iron...... Bg | eye Sipe dN ne RTA Lele PES aS oN | 
 
 The mineral varies much in the proportion of its consti- 
 tuents, as it is not crystallized. 3 
 
 B.B. it blackens in the inner flame, and yields water 
 without melting. With soda on charcoal yields. a globule 
 of copper. 
 
 Diff. Distinguished from green malachite as stated under 
 that species. 
 
 Obs. Accompanies other copper ores in Cornwall, Hun- 
 gary, the Tyrol, Siberia, Thuringia, etc. In Chili it is 
 abundant at the various mines. In Wisconsin and Missouri 
 it is so abundant as to be worked for copper. It was for- 
 merly taken for green malachite. It also occurs at the Som- 
 erville and Schuyler’s mines, N. J., at Morgantown, Penn., 
 and Wolcottville, Conn. 
 
 This ore in the pure state affords 30 per cent. of copper ; 
 but as it occurs in the rock will hardly yield one-third this 
 amount. Still, when abundant, as it appears to be in the 
 Mississippi Valley, it is a valuable ore. 
 
 General Remarks.—The most valuable sources of copper for the 
 
 arts are native copper, chalcopyrite or ‘‘yellow copper ore,” chaleocite 
 or “copper glance,” bornite or “‘ variegated copper ore,” malachite 
 
_ORES OF COPPER. 143 
 
 or ‘‘ green carbonate of copper,” chrysocolla or ‘‘ silicate,” cuprite or 
 ‘‘red oxide of copper ;” and occasionally tenorite or ‘‘ black copper.” 
 
 The principal copper regions, exclusive of the American, are as 
 follows. The Cornwall and Devon, England, where the ore is mostly 
 chalcopyrite ; about Mansfeld, in Prussia, having the ore distributed 
 through a bed of red shale in the Permian (Kupferschiefer), about 
 eighteen inches thick, making about 2} per cent. of the bed; the 
 Urals on their western slope, in the Permian, asin Mansfeld ; also 
 more productively on the eastern side of the Urals, at the Nischne 
 Tagilsk and Bogoslowskoi mines, in Silurian limestone where tra- 
 versed by eruptive rocks, and at the Gumeschewskoi mine, in argil- 
 iaceous shale, the ore chiefly malachite and cuprite ; in France, at 
 Chessy, near Lyons, of malachite and azurite, now of little value ; in 
 Norway, at Alten, and in Sweden, at Fahlun; in Hungary, at Schem 
 nitz, Kremnitz, Kapnik, and the Banat ; in Italy, at Monte Catini ; in 
 Spain, in the province of Huelva, where is the Rio Tinto mine, which 
 affords chalcopyrite, and also the sulphate (p. 188); in Portugal, at 
 San Domingo, near the mouth of the Guadiana ; in Algeria, Turkey, 
 China, Japan, Cape of Good Hope; in South Australia, where are 
 three prominent mines, the Burra, Wallaroo, and Moonta, their yield 
 in 1875, £451,500 ; New South Wales, the yield in 1875, about 6,000 
 tons, the value £508,800. 
 
 In South America, in Chili, in the vicinity of Copiapo, and less 
 abundantly at other places to the south ; in Bolivia, also in Peru, and 
 the Argentine Republic, but not much developed. In Cuba, but much 
 less productive than formerly. 
 
 In Eastern North America, some copper has been afforded by the 
 Triassic of New Jersey and the Connecticut Valley, but there are no 
 producing mines. Corinth, Vermont, and the Hiwassee mine, Ten- 
 nessee, are worked. The chief sources of copper are the veins of 
 Northern Michigan, near Lake Superior. The veins are connected with 
 trap-dikes intersecting a red Lower Silurian sandstone as stated on 
 page 131. The first discoveries of copper ore were made at Copper 
 Harbor. Near Fort Wilkins the black oxide was afterward found in a 
 large deposit, and 40,000 pounds of this ore were shipped to Boston. 
 On further exploration in the trap, the Cliff mine, 20 miles to the 
 westward, was laid open, where the largest masses of native copper 
 have been found, and which still proves to be highly productive. 
 Other veins have since been opened in various parts of the region, at 
 Eagle Harbor, Eagle River, Grand Marais, Lac La Belle, Agate Harbor, 
 Torch Lake, on the Ontonagon, in the Porcupine Mountains, and else- 
 where. The country north of Lakes Superior and Huron, Isle Royale 
 and the Michipicoton Islands, in Lake Superior, also afford copper ores, 
 and the vicinity of Quebec at the Acton and Harvey Hill mines, in rocks 
 referred to the Quehec formation. 
 
 In Western North America, in Arizona, there are large veins of 
 copper north of the Gila, on the borders of New Mexico, where are 
 the Santa Rita and Hanover mines, and the ores are cuprite, chalco- 
 cite, malachite ; there are rich veins also in Colorado, especially in 
 Gilpin and Park counties, in Nevada, and California. 
 
 The amount of copper produced in 1872, is stated as follows by 
 J. Arthur Phillips (Elements of Metallurgy) : 
 
144 DESCRIPTIONS OF MINERALS. 
 
 TEN OIADO A, ook a eee Oye ies 5,600 tons. 
 PE CUSEIA DD fy Sate ern ce eee coer 8,000 << 
 MRUBSID SG Chee OTs et eet ote oe Ae 6,500 << 
 Hungary 2 eee ne eee es ee 3,000 *¢ 
 Sweden and Norway........... ....5- 2,500 ** 
 Spain! (ome eae ee 71,0007 
 Portugal Met Sa. Sate. Ose ee 5,500“ 
 PAPA koe A IR ARs, oe 1,000 <* 
 South? Australian 72.2 pate eee 12,000 ‘‘ 
 South Africas Vee eo eee 7,500 * 
 Chiliand ‘Boliviavo4. Oo. 2) eee 46,500 * 
 United ‘States: 2070 eee 12,600 < 
 
 The total annual production is estimated by Phillips at 126,000 to 
 130,000 tons. 
 
 The metal copper was known in the earliest periods and was used 
 mostly alloyed with tin, forming bronze. The mines of Nubia and 
 Kthiopia are believed to have produced a great part of the copper of 
 the early Egyptians. Eubza and Cyprus are also mentioned as afford- 
 ing this metal to the Greeks. It was employed for cutting instru- 
 ments and weapons, as well as for utensils ; and bronze chisels are at 
 this day found at the Egyptian stone-quarries, that were once em- 
 ployed in quarrying. This bronze (chalkos of the Greeks, and @s of 
 the Romans) consisted of about 5 parts of copper to 1 of tin, a propor- 
 tion which produces an alloy of maximum hardness. Nearly the 
 same material was used in early times over Hurope ; and weapons and 
 tools have been found consisting of copper, edged with iron, indicating 
 the scarcity of the latter metal. Similar weapons have also been 
 found in Britain ; yet it is certain that iron and steel were well known 
 to the Romans and later Greeks, and to some extent used for warlike 
 weapons and cutlery. Bronze is hardened by hammering or pressure. 
 
 Copper knives, axes, chisels, spear heads, bracelets, etc., have been 
 found in the Indian Mounds of Wisconsin, Illinois, and the neighbor- 
 ing States ; and there is evidence that the Indians, besides using drift 
 masses of copper, knew of the copper veins of Northern Michigan, and 
 worked them, especially in the Ontonagon region, where their tools 
 and excavations have been discovered. 
 
 Copper at the present day is very various in its applications in the 
 arts. It is largely employed for utensils, for the sheathing of ships, 
 and for coinage. Alloyed with zinc it constitutes brass, and with tin 
 it forms bell-metal as well as bronze. 
 
 Brass consists of copper 65 per cent., zinc 35 ; with 58°5 per cent. of 
 zinc the alloy is silver-white; casting brass of 65-72 copper, 35-28 
 zinc ; or molu or Dutch metal, of 70-85 copper, 15-25 zinc, with 03 of 
 each, lead and tin ; brass for lathe-work of 60-70 copper, 28-88 zine, 2 
 lead ; Muntz metal, for the sheathing of ships, 60 copper, 89 zinc, 
 1 lead ; spelter solder for brass, copper 50, zine 50. 
 
 Bronze for medals consists of copper 98, tin 7; for speculum metal, 
 copper 60, tin 80, arsenic 10 ; for casting bronze, copper 82-83, tin 1-3, 
 zinc 17-18; for gun-metal, copper 85-92, tin 8-15; for bell-metal, 
 copper 65-80, tin 20-35, antimony 0-2; antique bronze, copper 67-95, 
 tin 8-15, lead 0-1, zine 0-16. 
 
 Lord Rosse used for the speculum of his great telescope, 126 parts 
 
ORES OF LEAD. 145 
 
 of copper to 574 parts of tin. The brothers Keller, celebrated for 
 their statue castings, used a metal consisting of 91:4 per cent. of cop- 
 per, 5°58 of zinc, 1°7 of tin, and 1:37 of lead. An equestrian statue of 
 Louis XIV., 21 feet high, and weighing 58,263 French pounds, was 
 cast by them in 1699, at a single jet. 
 
 An alloy of copper 90, and aluminum 10, is sometimes used in place 
 
 of bronze. 
 LEAD. 
 
 Lead occurs rarely native ; generally in combination with 
 sulphur; also rarely with arsenic, tellurium, selenium, and 
 in the condition of sulphate, carbonate, phosphate and 
 arsenate, chromate and molybdate. 
 
 The ores of lead vary in specific gravity from 5:5-8°2. 
 They are soft, the hardness of the species with metallic lus- 
 tre not exceeding 3, and others not over 4. They are easily 
 fusible before the blowpipe (excepting plumbo-resinite); and 
 with soda on charcoal (and often alone), malleable lead may 
 be obtained. The lead often passes off in yellow fumes, 
 when the mineral is heated on charcoal in the outer flame, 
 or it covers the charcoal with a yellow coating. 
 
 Native Lead. 
 
 A rare mineral, occurring in thin lamine or globules, 
 G.=11°35. Said to have been seen in the lava of Madeira ; 
 at Alston in Cumberland with galena; in the County of 
 Kerry, Ireland ; in an argillaceous rock at Carthagena; at 
 Camp Creek, Montana. 
 
 -Galenite.—Galena. Lead Sulphide. 
 
 Isometric. Cleavage cubic, eminent, and very easily ob- 
 tained. Also coarse or fine granular ; rarely fibrous. 
 
 
 
 Color and streak lead-gray. Lustre shining metallic. 
 ereetiere tts e29*h.) Gia 7-25-77, n 
 
146 DESCRIPTIONS OF MINERALS. 
 
 Composition. PbS=Sulphur 13-4, lead 86°6=100. Often 
 contains some silver sulphide, and is then called argentifer- 
 ous galena ; and at times zinc sulphide is present. The ore 
 of veins intersecting crystalline metamorphic rocks is most 
 likely to be argentiferous. The proportion of silver varies 
 greatly. In Europe, when it contains only 7 or 8 ounces 
 to the ton it is worked for the silver. The galenite of the 
 Hartz affords -03 to ‘05 per cent. of silver ; the English °02 
 to -03 per cent. ; that of Leadhills, Scotland, *03 to °06 ; 
 that of Pike’s Peak, Colorado, *05 to 06; that of Arkan- 
 sas, ‘03 to °05; that of Middletown, Ct., ‘15 to °20; that of 
 Roxbury, Ct., 1°85 5 that of Monroe, Ct., 3°0; while that of 
 Missouri afforded Dr. Litton only ‘0012 to 0027 per cent. 
 A little antimony or cadmium is sometimes present. 
 
 B.B. on charcoal, it decrepitates unless heated with cau- 
 tion, and fuses, giving off sulphur, coats the coal yellow, 
 and finally yields a globule of lead. 
 
 Diff. Galenite resembles some silver and copper ores in 
 color, but its cubical cleavage, or granular structure when 
 massive, will usually distinguish it. Its reactions before the 
 blowpipe show it to be a lead ore, and a sulphide. 
 
 Obs. Galena occurs in granite, limestone, argillaceous 
 and sandstone rocks, and is often associated with ores of 
 zine, silver and copper. Quartz, barite, or calcite is gener- 
 ally the gangue of the ore ; also at times fluor spar. The 
 rich lead mines of Derbyshire and the northern districts of 
 England, occur in the Subcarboniferous limestone; and the 
 same rock contains the valuable deposits of Bleiberg, in 
 Austria, and the neighboring deposits of Carinthia. The 
 ore of Cornwall is in true veins intersecting slates and 1s 
 argentiferous. At Freiberg in Saxony, it occupies veins in 
 eneiss; in the Upper Hartz, and at Przibram im Bohemia, 
 it traverses clay slate, of Lower Silurian age; at Sahla, 
 Sweden, it occurs in crystalline limestone. There are other 
 valuable beds of galena, in France at Poullaouen and Huel- 
 goet, Brittany, and at Villefort, department of Lozere ; in 
 Spain in the granite and argillyte hills of Linares, in Cata- 
 lonia, Grenada, and elsewhere ; in Savoy ; in Netherlands at 
 Vedrin, not far from Namur ; in Bohemia, southwest of 
 Prague; in J oachimstahl, where the ore is worked princi- 
 pally for its silver; 1m Siberia in the Daouria Mountains in 
 limestone, argentiferous and worked for the silver. 
 
 _ The deposits of this ore in the United States are remark- 
 
 ———— 
 
ORES OF LEAD. 147 
 
 ably for their extent. They occur in limestone, in the States 
 of Missouri, Illinois, lowa, and Wisconsin ; argillaceous 
 iron ore, pyrite, calamine and smithsonite (‘‘dry bone” of 
 the miners), blende (‘‘black-jack”), carbonate of lead or 
 _cerussite, and barite or heavy spar, are the most common 
 associated minerals; and less abundantly occur chalcopy- 
 _ rite and malachite, ores of copper; also occasionally the 
 lead ores, anglesite and pyromorphite ; and in the Mine La 
 Motte region, black cobalt, and linneite an ore of nickel. 
 Lead ore was first noticed in Missouri in 1700 and 1701. 
 In 1720 the mines were rediscovered by Francis Renault and 
 M. La Motte; and the La Motte bears still the name of the 
 latter. Afterward the country passed into the hands of 
 Spaniards, and during that period, in 1763, a valuable mine 
 was opened by Francis Burton, since called Mine a Burton. 
 The lead region of Wisconsin, according to Dr. D. D. 
 Owen, comprises 62 townships in Wisconsin, 8 in Iowa, and 
 10 in Illinois, being 87 miles from east to west, and 54 miles 
 from north to south. The ore, as in Missouri, is abundant, 
 and throughout the region there is scarcely a square mile 
 in which traces of lead may not be found. ‘'The principal 
 indications in the eyes of miners, as stated by Mr. Owen, 
 are the following : fragments of calcite in the soil, unless 
 very abundant, which then indicate that the vein is wholly 
 calcareous or nearly so ; the red color of the soil on the sur- 
 face, arising from the ferruginous clay in which the lead is 
 often imbedded ; fragments of lead (‘‘ gravel mineral”), 
 along with the crumbling magnesian limestone, and den- 
 dritic specks distributed over the rock; also, a depression of 
 the country, or an elevation, in a straight line ; or ‘ sink- 
 holes ;” or a peculiarity of vegetation in a linear direction. 
 The ore, according to Whitney, occupies chambers or open- 
 ings in the limestone instead of true veins, and in this 
 respect it is like that of Derbyshire and Northern England. 
 The mines of Wisconsin and Illinois are in Lower Silurian 
 limestone of the Trenton period, called the Galena lme- 
 stone; those of Southeastern Missouri, situated chiefly in 
 Franklin, Jefferson, Washington, St. Frangois, St. Géne- 
 vieve, and Madison counties, are in the ‘‘ Third Magnesian 
 limestone ;” also Lower Silurian, but, of the Calciferous or 
 Potsdam period ; those of Southwestern Missouri, situated 
 mostly in Newtown, Jasper, Lawrence, Green and Dade 
 counties, and in the western part of McDonald, Barry, 
 
148 DESCRIPTIONS OF MINERALS. 
 
 _ 
 
 Stone, and Christian counties, are in the ‘‘ Keokuk lime- 
 stone,” of the Subcarboniferous period, but partly in Web- 
 ster, Taney, Christian, and Barry counties, in the Lower 
 Silurian ‘‘magnesian limestone ;” those of Central Mis- 
 souri, situated in Moniteau, Cole, Miller, Morgan, and other 
 counties, are mostly in the Lower Silurian ‘ magnesian 
 limestone,” but partly, as in Northern Moniteau, in the Sub- 
 carboniferous. The conditions in which the ore occurs in 
 Missouri confirms the opinion of Prof. Whitney, as to there 
 being no true veins. Mr. Adolf Schmidt, in his account of 
 the Missouri lead ores, says that the deposits contain red 
 clay, broken chert, from the chert bed, and portions of the 
 limestone beds, along with the lead ; that the barite was in- 
 troduced after the lead ; that some caves are filled through 
 all their ramifications, while others are only partly filled ;, 
 and he adds that the same solvent waters that made the caves 
 and horizontal fissures or openings may have held the vari- 
 ous minerals in solution. In Derbyshire, England, the de- 
 posits contain fossils of Permian rocks, showing that, al- 
 though occurring in Subcarboniferous limestone, they were 
 much later in origin. 
 
 Galenite also occurs in the region of Chocolate River and 
 elsewhere, Lake Superior copper region ; on Thunder Bay, 
 and Black Bay; at Cave-in-Rock in Illinois, along with 
 fluorite; in New York at Rossie, St. Lawrence County, in 
 gneiss, In a vein 3 to 4 fect wide; near Wurtzboro’ in Sul- 
 livan County, a large vein in millstone grit ; at Ancram, 
 Columbia County ; Martinsburg, Lewis County, N. Y., and 
 Lowville ; in Maine, at Lubec ; also of less interest at Blue 
 Hill Bay, Birmingham and Parsonsfield ; in New Hampshire, 
 at Eaton, Bath, Tamworth and Haverhill; in Vermont, at 
 Thetford ; m Massachusetts, at Southampton, Leverett, and 
 Sterling, but without promise to the miner; at Newbury- 
 port, Mass., in a vein which is now worked ; at Middletown, | 
 Ct., formerly worked as a silver-lead mine ; in Virginia, in 
 Wythe County, Louisa County, and elsewhere; in North 
 Carolina, at King’s Mine, Davidson County, where the lead 
 appears to be abundant ; in Tennessee, at Brown’s Creek, 
 and at Haysboro’, near Nashville ; in Pennsylvania, at 
 Pheenixville ; in Michipicoton and Spar Islands, Lake Supe- 
 rior. In Nevada it is abundant on Watkins River, and at 
 Steamboat Springs, Galena district ; in Colorado, at Pike’s 
 Peak, etc.; in Arizona, in the Patagonian Mts., Santa Rita 
 
ORES OF LEAD. 149 
 
 Mts., and in Yuma County; in the Castle Dome, Eureka, 
 and other districts, where the ore is worked for the silver it 
 contains. 
 
 The lead of commerce is obtained from this ore. It is 
 also employed in glazing common stoneware: for this pur- 
 pose it is ground up to an impalpable powder and mixed in 
 water with clay; into this liquid the earthen vessel 1s dipped 
 and then baked. 
 
 Lead Selenides and Tellurides. 
 
 These various ores of lead are distinguished by the fumes before the 
 blowpipe, and by yielding, on charcoal, ultimately, a globule of lead. 
 
 Clausthalite, or lead selenide, has a lead-gray color, and granular 
 fracture, and is occasionally foliated. H.=2°d-3. G.=7-6-8'8. B.B. on 
 charcoal a horse-radish odor (that of selenium). From the Hartz. 
 There isa lead and copper selenide (Zorgite) which has the sp. gr. 
 77-5. A lead-and-mercury selenide (Lehrbachite) occurs in foliated 
 grains or masses of a lead-gray to bluish and iron-black color. 
 
 Altaite, or lead telluride. A tin-white cleavable mineral, with H.=3 
 -8°5, and G.=8°16. From the Altai Mountains. 
 
 Nagyagite, or Foliated tellurium, is a less rare species, remarkable 
 for being foliated like graphite ; color and streak blackish lead-gray ; 
 H. —1-1-5, G. =7-085. It contains Tellurium 32:2, lead 54:0, gold 9°0, 
 with often silver, copper, and some sulphur. From Transylvania. 
 
 Antimonial and Arsenical Sulphides of lead. These include Sartorite, 
 Zinkenite, Plagionite, Jamesonite, Dufrenoysite, Boulangerite, Kobel- 
 lite, Meneghinite, Geocronite ; also Brongniardite and Frevestebenite, 
 in which silver is also present, and Stylotypite and Aikenite in which 
 copper is also present. 
 
 Minium.—Oxide of Lead. 
 
 Pulverulent. Color bright red, mixed with yellow. G.= 
 4:6. Composition, Pb, O, Affords globules of lead in the 
 reduction flame of the blowpipe. 
 
 Obs. Occurs at various mines, usually associated with 
 galena, and is found abundantly at Austin’s: Mines, Wythe 
 County, Virginia, with white lead ore. 
 
 Uses. Minium is the red lead of commerce ; but for the 
 arts it is artificially prepared. 
 
 Plumbic ochre is lead protoxide, of a yellow color. 
 
 Mendipite. Color white, yellowish or reddish, nearly opaque. Lustre 
 pearly. G.=7-7:1. PbCl+Pb O=Chloride of lead 88°4, lead oxide 
 61:-6.. From Mendip Hills, Somersetshire. Cotunnite is a chloride of 
 lead, Pb Clo, occurring at Vesuvius in white acicular crystals. It con- 
 tains 74°5 per cent. of lead. 
 
 Plumbogummite. In globular forms, having a lustre somewhat 
 like gum arabic, and a yellowish or reddish-brown color, H.=4-4°5. 
 
150 DESCRIPTIONS OF MINERALS. 
 
 G@.—6-3-6:4. Also a variety 4-49. Consists of lead, alumina, and 
 water. From Huelgoet in Brittany, and at a lead mine in Beaujeu ; 
 also from the Missouri mines, with black cobalt, and from Canton 
 mine, Ga. 
 
 Anglesite.—Lead Sulphate. 
 
 Trimetric. In rhombic prisms 
 and other forms. Lateral cleavage. 
 IA I=103° 434’, Also massive ; la- 
 mellar or granular. 
 
 Color white or slightly gray or 
 green. Lustre adamantine; some- 
 times a litte resinous or vitreous. 
 Transparent to nearly opaque. Brit- 
 tle. H.=2°75-3, G. =6:1-6°4. 
 
 Composition. Pb Os 8, affording 
 about 73 per cent. of oxide of lead. 
 
 
 
 PHC@NIXVILLE. B.B. fuses in the flame of a candle, 
 and, on charcoal, yields lead with 
 soda. 
 
 Diff. Resembles aragonite and some other earthy species ; 
 but this and the other ores of lead are at once distinguished 
 by specific gravity, and also by their yielding lead in blow- 
 pipe trials. Differs from the carbonate of lead in lustre 
 and in not dissolving with effervescence in acid. 
 
 Obs. Usually associated with galena, and results from its 
 decomposition. Occurs in fine crystals at Leadhills and 
 Wanlockhead, Great Britain, and also at other foreign lead 
 mines. In the United States, it is found at the lead mines 
 of Missouri and Wisconsin ; in splendid crystallizations at 
 Phoenixville, Pa.; sparingly at the Walton gold mine, Louisa 
 County, Va.; at Southampton, Mass.; in Arizona, and in 
 Cerro Gordo, Cal. 
 
 Caledonite is a lead-and-copper sulphate, of azure-blue color. It is 
 remarkable for a very perfect cleavage in one direction. G.=6°4. 
 From Leadhills and Roughten Gill, England; also from Mine la Motte, 
 Missouri. 
 
 Lead selenate. A sulphur-yellow mineral, occurring in small glob- 
 
 ules, and affording before the blowpipe on charcoal a garlic odor, and 
 finally a globule of lead. It is named Kerstenite, 
 
 Crocoite.—Crocoisite. Lead Chromate. 
 
 Monoclinic. In oblique rhombic prisms, massive, of a 
 bright red color and translucent. Streak orange-yellow. 
 H.=2°5-3. G.=5°'9-6'1. 
 
ORES OF LEAD. LoL 
 
 a 
 
 Composition. Pb O: Cr=Chromium trioxide 31:1, lcad 
 oxide 68-9. Blackens and fuses, and forms a shining slag 
 containing.globules of lead. 
 
 Obs. Occurs in gneiss at Beresof in Siberia, and also in 
 Brazil. This is the chrome yellow of the painters. 
 
 Phenicochroite (or Melanochroite) is another lead chromate, contain. 
 ing 23°0 of chromium trioxide, and having a dark red color; streak 
 brick-red. Crystals usually tabular and reticulately arranged. G.=0°75. 
 From Siberia. 
 
 Vauquelinite. A lead and copper chromate, of a very dark green 
 or pearly black color, occurring usually in minute irregularly aggre- 
 gated crystals ; also reniform and massive. H.=2°5-8. G.=5°5-5'8. 
 From Siberia and Brazil; also at the lead mine near Sing Sing, in 
 mammillary concretions. 
 
 Stolzite, or lead tungstate. In square octahedrons or prisms. Color 
 green, gray, brown, or red, Lustre resinous. H.=2°5-3, G.=7°9- 
 81. Contains 51 of tungstic acid and 49 of lead. 
 
 Wulfenite, or lead molybdate. In dull-yellow octahedral crystals, 
 and also massive. Lustre resinous. Contains molybdenum trioxide 
 34:25, protoxide 64°42. From Bleiberg and elsewhere in Carinthia ; 
 also Hungary. It has been found in small quantities in the Southamp- 
 ton lead mine, Mass., and in fine crystals, at Pheenixville, Penn. 
 
 Lead Sulphato-carbonates. There are two whitish or grayish ores 
 of this composition called Lanarkite and Leadhillite. The former con- 
 tains 71 per cent. of carbonate of lead ; the latter, AT. 
 
 Pyromorphite.—Lead Phosphate. 
 
 Hexagonal. In hexagonal prisms ; often 
 in crusts made of crystals. Also in globules 
 or reniform, with a radiated structure. 
 
 Color bright green to brown ; sometimes 
 fine orange-yellow, owing to an intermix- 
 ture with chromate of lead. Streak white 
 or nearly so. Lustre more or less resinous. 
 Nearly transparent to subtranslucent. Brit- 
 eee erecta. Gi 6'5-7 1. 
 
 Composition. Pb,03P.+4 Pb Cl.=Phos- 
 phorus pentoxide 15°71, lead oxide 82:27, chlorine 2°62 
 —100-60. B.B. fuses easily in the forceps, coloring the 
 flame bluish green. On charcoal fuses, and on cooling, 
 the globule becomes angular ; the coal is coated white from 
 the chloride, and nearer the assay, yellow from lead oxide. 
 Soluble in nitric acid. 
 
 Diff. Has some resemblance to beryl and apatite ; but is 
 quite different in its action before the blowpipe, and much 
 higher in specific gravity. 
 
 
 
152 DESCRIPTIONS OF MINERALS. 
 
 Ods. Leadhills, Wanlockhead, and other lead mines of 
 Europe are foreign localities. In the United States, very 
 handsome crystallized specimens occur at King’s Mine, in 
 Davidson County, N. C.; other localities are the Perkiomen 
 and Pheenixville mines, Pa. ; the Lubec lead mines, Me. ; 
 Lenox, N. Y.; formerly, a mile south of Sing Sing, N. Y.; 
 and the Southampton lead mine, Mass. | 
 
 The name pyromorphite is from the Greek pur, fire, and 
 morphe, form, alluding to its crystallizing on cooling from 
 fusion before the blowpipe. 
 
 Mimetite. A lead arsenate, resembling pyromorphite in crystalliza- 
 tion, but giving a garlic odor on charcoal before the blowpipe. Color 
 pale yellow, passing into brown. H.=2-75-8:5. G.=6°41. Com- 
 position, Pb,O, As, +14 Pb Cl,=Arsenic pentoxide 23°20, lead oxide 
 74:96, chlorine 2°30—100°55. From Cornwall and elsewhere ; Pho- 
 nixville, Pa. 
 
 Hedyphane is a variety of mimetite containing much lime. It 
 occurs amorphous, of a whitish color, and adamantine lustre. aa 
 3°5-4. G.=5°4-5'5. 
 
 Karyinite. A lead arsenate containing manganese and calcium, 
 from Norway. 
 
 Ecdemite. A lead chloro-arsenate. 
 
 Vanadinite. A lead vanadate occurring in hexagonal prisms like 
 pyromorphite, and also in implanted globules. Color yellow to red- 
 dish brown. H.—2°75-3. G.=6°6-7°3. From Mexico; also from 
 Wanlockhead in Dumfriesshire. 
 
 Monimolite. A yellow lead antimonate. 
 
 Nadorite. A yellow lead chlor-antimonate 
 
 Bindheimite. A hydrous lead antimonate. 
 
 Cerussite.— White Lead Ore. Lead Carbonate. 
 
 Trimetric. In modified right rhombic prisms, and often 
 in compound crystals, two or three crossing one another as 
 
 
 
 in fig. % JA I=117°13’. Also in six-sided prisms like 
 aragonite. Also massive ; rarely fibrous. 
 
 Color white, grayish, light or dark. Lustre adamantine. 
 Brittle. H.=3-3°5. G.=6:46-6 “48, 
 
LEAD, 153 
 
 Composition. PbhO,C=Carbon dioxide 16:5, lead oxide 
 83°5=100. B.B. decrepitates, fuses, and with care on char- 
 coal affords a globule of lead. ffervesces in dilute nitric 
 acid, 
 
 Diff. Like anglesite, distinguished from most of the spe- 
 cies 1t resembles by its specific gravity and yielding lead 
 when heated. From anglesite it differs in giving lead alone 
 before the blowpipe, as well as by its solution and efferves- 
 cence with nitric acid, and its less glassy lustre. 
 
 Obs. Associated usually with galena. Leadhills, Wan- 
 lockhead, and Cornwall have afforded splendid crystalliza- 
 tions ; also Linares, in Spain, and other lead mines on the 
 continent of Europe. 
 
 In the United States, handsome specimens are obtained 
 at Austin’s Mines, Wythe County, Virginia, and at King’s 
 Mine, in Davidson’s County, North Carolina; at the latter 
 place it has been worked for lead, and it is associated with 
 native silver and pyromorphite. Perkiomen and Phoenix- 
 ville, Penn., afford good crystals. It occurs also at ‘* Vallée’s 
 Diggings,” Jefferson County, Missouri, and other mines, in 
 that State; at Brigham’s Mine, near the Blue Mounds, 
 Wisconsin, partly in stalactites; at ‘‘ Deep Diggings,” in 
 crystals; and at other places, both massive and in fine 
 crystallizations. 
 
 When abundant, this ore is wrought for lead. Large 
 quantities occur about the mines of the Mississippi Valley. 
 It was formerly buried up in the rubbish as useless, but it 
 has since been collected and smelted. It is an exceedingly 
 rich ore, affording in the pure state 75 per cent. of lead. 
 
 Carbonate of lead is the ‘‘ white lead” of commerce, so 
 extensively used as a paint. The material for this purpose 
 is, however, artificially made. 
 
 Phosgenite or Corneous Lead. A chloro-carbonate of lead, occurring 
 in whitish adamantine crystals. H.=2°75-4. G.=6-6°31. Composi- 
 tion, PbO,C+PbCl. From Derbyshire and Germany. 
 
 Hydrocerussite. Hydrous lead carbonate. From Sweden. 
 
 Ganomalite is a white lead-manganese silicate, affording 34°89 per 
 
 cent. of leadoxide. From Sweden. AHyalotecite is a lead-barium-lime 
 silicate. Both are from Longban, Sweden. 
 
 General Remarks.—The lead of commerce is derived almost wholly 
 from the sulphide of lead or galenite, the localities of which have 
 already been mentioned. In some mining regions, the carbonate and 
 sulphate are abundant. 
 
 The lead mines of the Central United States afforded in 1826, 1,770 
 tons ; in 1842, 17,840 tons; and of late years, 12,000 to 15,000 tons. 
 
154 DESCRIPTIONS OF MINERALS. 
 
 Nevada produced 10,000 tons in 1870, and 50,000 in 1875. According 
 to Phillips, England produced in 1272, 60,450 tons ; Prussia, in 1871, 
 49,500 tons ; Spain, in 1878, 102,600 tons ; France, 2,500 tons ; Italy, 
 15,500 tons ; Austria, 10,000 tons. 
 
 ZINC. 
 
 Zine occurs in combination with sulphur and oxygen ; 
 and also in the condition of silicate, carbonate, sulphate, 
 and arsenate. Itis also a constituent of one variety of the 
 species spinel. The chief sources of the metal are smith- 
 sonite or the carbonate; willemite and calamine, or sili- 
 cates; zincite, or the oxide; sphalerite (blende), or the 
 sulphide ; and franklinite. 
 
 Sphalerite.—Blende, Zinc Sulphide. 
 
 Isometric. In dodecahedrons, octahedrons, and other allied 
 forms, with a perfect dodecahedral cleavage. Also masvive ; 
 
 sometimes fibrous. Color wax-yellow, brownish-yellow, to 
 black, sometimes green, red and white ; streak white, to red- 
 dish brown. Lustre resinous or waxy, and brilhant on 4 
 cleavage face ; sometimes submetallic. Transparent to sub- 
 translucent. Brittle. H.=3-b-4. G.=3°9-4:2. Some 
 specimens become electric with friction, and give off a yel- 
 low light when rubbed with a feather. 
 
 Composition. Zn S=Sulphur 83, zinc 67=100. Contains 
 frequently a portion of iron sulphide when dark colored ; 
 often also 1 or 2 per cent. of cadmium sulphide, especially 
 the red variety. Nearly infusible alone and with borax. 
 Dissolves in nitric acid, emitting sulphuretted hydrogen. 
 Strongly heated on charcoal yields fumes of zine. 
 
 Diff. This ore 1s characterized by its waxy lustre, perfect 
 cleavage, and its being nearly infusible. Some dark varieties 
 look a little like tin ore, but their cleavage and inferior 
 hardness distinguish them; and some clear red crystals, 
 
 
 
ZINC. Loo 
 
 which resemble garnet, are distinguished by the same char- 
 aracters and also by their very difficult fusibility. 
 
 Ods. Occurs in rocks of all ages, and is associated gener- 
 ally with ores of lead; often also with copper, iron, tin, and 
 silver ores. ‘Che lead mines of Missouri and Wisconsin afford 
 this ore abundantly. Other localities are in Maine, at Lu- 
 bec, Bingham, Dexter, Parsonsfield ; in New Hampshire, 
 at Haton, Warren, Haverhill, Shelburne; in Vermont, at 
 Hatfield ; in Connecticut, in Brookfield, Berlin, Roxbury, 
 and Monroe; in New York, at Ancram lead mine, the 
 Wurtzboro’ lead vein, at Lockport, Root, 2 miles southeast 
 of Spraker’s Basin, in Fowler, at Clinton; at Franklin, N. 
 J., colorless (Cleiophane) ; in Pennsylvania, at the Perkio- 
 men lead mine ; in Virginia, at Austin’s lead mine, Wythe 
 County; in Tennessee, near Powell’s River, and at Haysboro’; 
 at Prince’s Mine, Spar Island, Lake Superior, with ores of sil- 
 ver; in Beauce Co., Canada, where it is slightly auriferous. 
 
 This ore is the Black-jack of miners. 
 
 Blende is a useful ore of zinc, though more difficult of re- 
 duction than calamine. By its decomposition (like that of 
 pyrite), it affords sulphate of zinc or white vitriol. 
 
 Wurtzite is zinc sulphide in hexagonal crystals from Bolivia. Huas- 
 colite and Youngite are zinc-lead sulphides. 
 
 Zincite.—Red Zinc Ore. Red Zinc Oxide. 
 
 Hexagonal. Usually in foliated masses, or in disseminated 
 grains ; cleavage eminent, nearly like that of mica; but the 
 lamine brittle, and not so easily separable. 
 
 Color deep or bright red; streak orange-yellow. Lustre 
 brilliant, subadamantine. ‘Translucent or subtranslucent. 
 H.=4-4'5. G.=5-4-5°7. Thin scales by transmitted light 
 deep yellow. 
 
 Composition. Zn O=Oxygen 19°7, zinc 80°3=100. B.B. 
 infusible alone, but yields a yellow transparent glass with 
 borax ; on charcoal, a coating of zinc oxide. Dissolves in 
 nitric acid without effervescence. 
 
 Diff. Resembles red stilbite, but distinguished by its in- 
 fusibility and also by its mineral associations. 
 
 Obs. Occurs with franklinite at Mine Hill and Sterling 
 Hill, Sussex County, N. J. 
 
 A good ore of zinc, and easily reduced. 
 
 Voltzite. A compound of sulphur, oxygen and zinc, 4 Zn 8 +Zn O. 
 
 Occurs in implanted globules of a dirty rose-red color, with a pearly 
 lustre on a cleavage surface. From France, and near Joachimstahl, 
 
156 DESCRIPTIONS OF MINERALS. 
 
 Goslarite.—Sulphate of Zinc. White Vitriol, 
 
 Trimetric. Cleavage perfect in one direction. J A I= 
 90° 42’. 
 
 Color white. Lustre vitreous. Easily soluble; taste as- 
 tringent, metallic, and nauseous. Brittle. H.=2-2°. ize 
 1:9-2°1. 
 
 Composition. ZnO,S+7 aq. —Zince oxide 28°2, sulphur 
 trioxide 27:9, water 43°9—100. B.B. gives off fumes of 
 zinc on charcoal, which cover the coal. 
 
 Obs. Results from the decomposition of blende. Occurs 
 in the Hartz, in Hungary, in Sweden, and at Holywell in 
 Wales. 
 
 Sulphate of zinc is extensively employed in medicine and 
 dyeing. For these purposes itis prepared to a large extent 
 from blende by decomposition, though this affords, owing to 
 its impurities, an impure sulphate. It is also obtained by 
 direct combination of zinc with sulphuric acid. 
 
 White Vitriol, as the term is used in the arts, is one form 
 of sulphate of zinc, made by melting the crystallized sul- 
 phate, and agitating till it cools and presents an appearance 
 like loaf sugar. 
 
 Kittigite. A hydrous zinc-cobalt arsenate of reddish color (owing 
 to presence of cobalt) from Schneeberg 
 
 Adamite. A hydrous zinc-arsenate of honey-yellow to violet color, 
 from Chili. 
 
 Smithsonite.—Carbonate of Zinc. 
 
 Rhombohedral. R A R=107° 40’. Cleavage R perfect. 
 Massive or incrusting ; reniform and stalactitic. 
 
 Color impure white, sometimes green or brown; streak 
 uncolored. Lustre vitreous or pearly. Subtransparent to 
 iranstucent, Brittle. H.=5. (Ge gesam 
 
 Composition. Zn O, C=Carbon dioxide 35:2, zinc oxide 
 64:8 (four-fifths of which is pure zinc)=100. Often con- 
 tains some cadmium. B.B. infusible alone, but carbonic 
 acid and oxide of zinc are finally vaporized. Effervesces in 
 nitric acid. Negatively electric by friction. 
 
 Diff. The effervescence with acids distinguishes this 
 mineral from the following species ; and the hardness, diffi- 
 cult fusibility, and the zinc fumes before the blowpipe, from 
 the carbonate of lead or other carbonates. Besides, the 
 crystals over a drusy surface terminate usually in sharp 
 three-sided pyramids. 
 
ZINC. 157 
 
 Obs. Occurs commonly with galena or blende, and usual- 
 ly in calcareous rocks. Found in Siberia, Hungary, Sile- 
 sia; at Bleiberg in Carinthia ; near Aix-la-Chapelle in the 
 Lower Rhine, and largely in Derbyshire and elsewhere in 
 England. In the United States, it is abundant at Vallée’s 
 Diggings in Missouri, and at other lead “ diggings”’ in lowa 
 and Wisconsin ; also in Claiborne County, Tenn. Sparingly 
 also at Hamburg, near the Franklin Furnace, N. J.3 at the 
 Perkiomen lead mine, Pa., and at a lead mine in Lancaster 
 County. 
 
 Hydrozincite is a hydrous zine carbonate, Zn 0, C+2 Zn O. H, of a 
 whitish color, with G.=3°58-3'8. 
 
 Aurichalcite is a hydrous carbonate of zinc and copper, occurring in 
 drusy incrustations of acicular crystals, having a pale verdigris-green 
 color. From Siberia, Hungary, England, and Lancaster, Pa. 
 
 Buratite is a lime aurichalcite. 
 
 Willemite.—Zinc Silicate. Troostite. 
 
 Rhombohedral. RA R=116° 1’. In hexagonal prisms, 
 and also massive. 
 
 Color whitish, greenish yellow, apple-green, flesh-red, yel- 
 lowish brown. Streak uncolored. ‘Transparent to opaque. 
 Pepe 55. G.=3 89-41-18. 
 
 Composition. Zn O, Si=Silica 27-1, zinc oxide 7%2°9= 
 100. B.B. fuses with difficulty to a white enamel; on char- 
 coal, and most easily on adding soda, yields a coating which is 
 
 ellow while hot, and white on cooling, and which, moistened 
 ‘vith cobalt solution and treated in O.F., is colored bright 
 green. Gelatinizes with hydrochloric acid. 
 
 Obs. From Moresnet, between Litge and Aix-la-Chapelle ; 
 Raibel in Carinthia; Greenland. Abundant at both Frank- 
 lin and Sterling, mixed with zincite, and used as an ore of 
 ae : also in prismatic crystals that occasionally are six Inches 
 ong. . 
 
 ; Calamine.—Hydrous Zinc Silicate. Galmei. 
 
 Trimetric. In rhombic prisms, the opposite extremities 
 with unlike planes. J, J=104° 13°. Cleavage perfect 
 parallel to 7. Also massive and incrusting, mammillated or 
 stalactitic. 
 
 Color whitish or white, sometimes bluish, greenish, or 
 brownish. Streak uncolored. Transparent to translucent. 
 Lustre vitreous or subpearly. Brittle. H.=4°0-0. ee 
 3:16-3:9. Pyro-electric. 
 
158 DESCRIPTIONS OF MINERALS. 
 
 Composition. Zn, O, Si+aq. = Silica 25-0, zine oxide 675, 
 water 7'5=100. 
 
 B.B. alone it is almost infusible. Forms a clear glass 
 with borax. In heated sulphuric acid it dissolves, and the 
 solution gelatinizes on cooling. 
 
 Diff. Differs from calcite and aragonite by its action with 
 acids; from a salt of lead, or any zeolite, by its infusibility ; 
 from chalcedony by its inferior hardness, and its gelatiniz- 
 ing with heated sulphuric acid; and from smithsonite by 
 not effervescing with acids, and by the rectangular aspect of 
 its crystals over a drusy surface. 
 
 Obs. Occurs with calamine. In the United States it is 
 found at Vallée’s Diggings, Mo.; at the Perkiomen and 
 Pheenixville lead mines; on the Susquehanna, opposite 
 Selinsgrove ; at Friedensville in Saucon Valley, two miles 
 from Bethlehem, Pa., with massive blende. Abundantly at 
 Austin’s Mines, Wythe County, Va. Valuable as an ore of zine. 
 
 Hopeite is a rare mineral occurring in grayish-white crystals or mas- 
 sive, with calamine, and supposed to be a hydrous zine-phosphate. 
 _ Franklinite, an ore of iron, manganese and zine, is described under 
 iron, on page 179. 
 
 General Remarks.—The metal zinc (spelter of commerce) is supposed 
 to have been unknown in the metallic state to the Greeks and Romans. 
 It has been long worked in China, and was formerly imported in large 
 quantities by the East India Company. 
 
 The principal mining regions of zinc in the world are in Upper Sile- 
 sia, at Tarnowitz and elsewhere ; in Poland ; in Carinthia, at Raibel and 
 Bleiberg ; in Netherlands at Limberg; at Altenberg, near Aix-la- 
 Chapelle in the Prussian province of the Lower Rhine ; in England, 
 in Derbyshire, Alstonmoor, Mendip Hills, etc.; in the Altai in Russia ; 
 besides others in China, of which little is known. In the United 
 States, smithsonite and calamine occur with the lead of the West in 
 large quantities. They were formerly considered worthless and thrown 
 aside, under the name of ‘‘dry bone.” In Tennessee, Claiborne 
 County, there are workable mines of the same ores. Calamine occurs 
 at Friedensville, Pennsylvania, along with massive blende; the bed 
 has been, but is not now worked. The zincite, wiJlemite, and frank- 
 linite of Franklin, New Jersey, are together worked as a zinc ore, 
 and both zinc and zinc oxide are produced. Blende is sufficiently abun- 
 dant to be worked at the Wurtzboro’ lead mine, Sullivan County, New 
 York ; at Eaton and Warren, in New Hampshire ; at Lubec, in Maine ; 
 at Austin’s Mine, Wythe County, Virginia, and at some of the Missouri 
 lead mines. 
 
 The amount of zinc produced in 1872, in Europe, was about 45,745 
 tons for Belgium; 55,744 for Germany ; 3,000 for Austria ; 15,000 for 
 Great Britain ; 4,400 for France; 4,400 for Spain: making the total 
 amount 128,289 tons. In the United States the amount of zinc made 
 in 1875 was about 15,000 tons ; of zinc oxide, 8,500 tons. 
 
 —~~—“= rr 
 
TIN. 159 
 
 Zinc is a brittle metal, but admits of being rolled into sheets when 
 heated to about 212° F. In sheets it is extensively used for roofing 
 and other purposes, it being of more difficult corrosion, much harder, 
 and also very much lighter than lead. It is also employed largely for 
 coating (that is, making what is called galvanized) iron, Its alloys with 
 copper (page 144) are of great importance. 
 
 The white oxide of zinc is much used for white paint, in place of 
 white lead ; and also in making a glass for optical purposes. 
 
 An impure oxide of zinc, called cadmia, often collects in large quan- 
 tities in the flues of iron and other furnaces, derived from ores of zinc 
 mixed with the ores undergoing reduction. A mass weighing 600 
 pounds was taken from a furnace at Bennington, Vt. It has been ob- 
 served in the Salisbury iron furnace, and at Ancram, in New Jersey, 
 where it was formerly called Ancramite, 
 
 CADMIUM. 
 
 There is but a single known ore of this rare metal. It is 
 a sulphide, and is called Greenockite. It occurs in hexagonal 
 prisms, with dissimilar pyramidal termination, of a light 
 yellow color, high lustre, and nearly transparent. H.zea- 
 3°5. G.=—4-8-5. From Bishopton, Scotland. 
 
 Cadmium is often associated with zinc in sphalerite and 
 calamine. The cadmiferous sphalerite is called Przibramite. 
 
 The metal cadmium is white like tin, and is so soft that 
 ‘it leaves a trace upon paper. It fuses at 442° F, It was 
 discovered by Stromeyer in 1818. 
 
 
 
 TIN. 
 
 Tin has been reported as occurring native in the gold 
 washings of the Ural, and in Bolivia. There are two ores, 
 a sulphide and an oxide. It also occurs in some ores of 
 columbium, tantalum, and tungsten. 
 
 Stannite.—Tin Pyrites, Sulphuret of Tin. Tin Sulphide. 
 
 Commonly massive, or in grains. Color steel-gray to iron- 
 black ; streak blackish. Brittle H.=4. G.=4:3-4°6. 
 
 Composition. Sulphur 30, tin 27, copper 30, iron 13=100. 
 
 Obs. From Cornwall, where it is often called bell-metal 
 ore, from its frequent bronze appearance ; also from Ireland 
 and the Erzgebirge. | 
 
160 DESCRIPTIONS OF MINERALS. 
 
 Cassiterite.—Tin Ore. Tin Oxide. 
 
 Dimetric. In square prisms and octahedrons; often com- 
 ib pounded. 1A1=121° 40’; la 2. 
 
 . Alt (over the summit) 112° 
 4 SY 10', (over a terminal edge) 
 133° 31’. Cleavage indistinct. 
 
 Also massive, and in grains. 
 Color brown or black, with 
 a high adamantine lustre when |. 
 “abs j in crystals. Streak pale gray 
 * to brownish. Nearly trans- 
 parent to opaque. H.=6-7. G.=6-4-7-1. 
 Composition. Sn O,= Oxygen 21°33, tin 78°67 ; often con- 
 tains a little iron, and sometimes tantalum. 
 B.B. alone infusible. On charcoal with soda, affords a 
 globule of tin. 
 Stream tin is the gravel-like ore found in debris in low 
 
 
 
 grounds. Wood tin occurs in botryoidal and reniform shapes 
 
 with a concentric and radiated structure ; and toad’s-eye tin 
 is the same on a small scale. 
 
 Diff. Tin ore has some resemblance to a dark garnet, to 
 black zine blende, and to some varieties of tourmaline. It is 
 distinguished by its infusibility, and its yielding tin before 
 
 the blowpipe on charcoal with soda. It differs from blende. 
 
 also in its superior hardness. 
 
 Obs. Tin ore occurs in veins in the crystalline rocks, 
 granite, gneiss, and mica slate, associated often with wolfram, 
 copper and iron pyrites, topaz, tourmaline, mica or tale, and 
 albite.. Cornwall is one of its most productive localities. 
 It is also worked in Saxony, at Altenberg, Geyer, Hhren- 
 friedersdorf and Zinnwald; in Austria, at Schlackenwald and 
 other places ; in Malacca, Pegu, China, and especially the 
 Island of Banca in the East Indies; in Queensland and 
 Northern New South Wales, Australia, in large quantities ; 
 in Greenland. It occurs also in Galicia, Spain; at Dale- 
 carlia in Sweden ; in Russia; in Mexico at Durango; 
 and-Bolivia. In the United States it has been found spar- 
 ingly at Chesterfield and Goshen, Mass.; in some of the Vir- 
 ginia gold mines ; in Lyme and Jackson, N. H.; and in the 
 Temescal Range, California. 
 
 General Remarks.—The principal tin mines now worked, are those 
 
 of Cornwall, Banca, Malacca, and Australia. 
 The Cornwall mines were worked long before the Christian era. 
 
 hegage 
 
TIN. 161 
 
 Herodotus, 450 years before Christ, is believed to allude to the tin 
 islands of Britain under the cabalistic name Cassiterides, derived from 
 the Greek kassiteros, signifying tin. The Phoenicians are allowed to 
 have traded with Cornubia (as Cornwall was called, it is supposed 
 from the horn-like shape of this extremity of England). The Greeks 
 residing at Marseilles were the next to visit Cornwall, or the isles ad- 
 jacent, to purchase tin; and after them came the Romans, whose 
 merchants were long foiled in their attempts to discover the tin market 
 of their predecessors. 
 
 Camden says : ‘‘It is plain that the ancient Britons dealt in tin mines 
 from the testimony of Diodorus Siculus, who lived in the reign of 
 Augustus, and Timaus, the historian in Pliny, who tells us that the 
 Britons fetched tin out of the Isle of Icta (the Isle of Wight), in their 
 little wicker boats covered with leather. The import of the passage 
 in Diodorus is that the Britons who lived in those parts dug tin out of 
 a rocky sort of ground, and carried it in carts at low water to certain 
 neighboring islands ; and that from thence the merchants first trans- 
 ported it to Gaul, and afterwards on horseback in thirty days to the 
 springs of Eridanus, or the city of Narbona, as to a common mart. 
 Aithicus too, another ancient writer, intimates the same thing, and 
 adds that he had himself given directions to the workmen.” In the 
 opinion of the learned author of the Britannica here quoted, and others 
 who have followed him, the Saxons seem not to have meddled with 
 the mines, or, according to tradition, to have employed the Saracens ; 
 for the inhabitants of Cornwall to this day call a mine that is given 
 over working Attal-Sarasin, that is, the leavings of the Saracens. 
 
 The Cornwall veins, or odes, mostly run east and west, with a dip 
 —hade, in the provincial dialect—varying from north to south; yet 
 they are very irregular, sometimes crossing each other, and sometimes 
 a promising vein abruptly narrows or disappears ; or again they spread 
 out into a kind of bed or floor. The veins are considered worth work- 
 ing when but three inches wide. The gangue is mostly quartz, with 
 some chlorite. Much of the tin is also obtained from beds of loose 
 stones or gravel (called shodes), and courses of such gravel or tin de- 
 bris are called streams, whence the name stream tin. . 
 
 The Australian mines are mainly in the New England district of 
 Northern New South Wales, and the adjoining part of Queensland, and 
 a large part of the ore goes north through Queensland. The value of 
 the tin exported in 1875 from Queensland was £88,224, and from New 
 South Wales (Ann. Rep. Dept. of N. 8. W. Mines, 1876), £561,311, cor- 
 responding to 6,058 tons of tin in ingots, besides 2,022 tons of ore. 
 The value of all the tin raised in N. 8. Wales, prior to 1875 is £866,461. 
 Beechwood, Victoria, also affords a little tin. 
 
 The annual production of tin in 1871 in Great Britain was 11,520 
 tons, and in Banca and Malacca, 7,500. 
 
 Tin is used in castings, and also for coating other metals, especially 
 iron and copper. Copper vessels thus coated were in use among the 
 Romans, though not common. Pliny says that the tinned articles 
 could scarcely be distinguished from silver, and his use of the words 
 incoquere and incoctilia seems to imply, as a writer states, that the 
 process was the same as for the iron wares of the present day, by 7m- 
 mersing the vessels in melted tin. Its alloys with copper are mentioned 
 on page 144, “i 
 
162 DESCRIPTIONS OF MINERALS. 
 
 Tin is also used extensively as tinfoil ; but most tinfoil consists be- 
 neath the surface of lead,and is made by rolling out plates of lead coated 
 with tin. With quicksilver it is used to cover glass in the manufac- 
 ture of mirrors. ‘Tin oxide (dioxide), obtained by chemical processes, 
 is employed, on account of its hardness, in making a paste for sharp. 
 ening fine cutting instruments, and also to some extent in the prepara- 
 tion of enamels. The chlorides of tin are important in the precipita- 
 tion of many colors as lakes, and in fixing and changing colors in dye- 
 ing and calico-printing. The bisulphide has a golden lustre, and was 
 
 termed aurum musivum, or mosaic gold, by the alchemists. It ismuch 
 
 used for ornamental painting, for paper-hangings and other purposes, 
 under the name of bronze powder. 
 
 TITANIUM. 
 
 Titanium occurs in nature combined with oxygen, form- 
 ing titanium dioxide or titanic acid, and also in oxygen com- 
 binations with iron and calcium, and in some silicates. It 
 has not been met with native. 
 
 The ores are infusible alone before the blowpipe, or nearly 
 so. Their specific gravity is between 3-0 and 4:5. 
 
 Rutile. 
 
 Dimetric. In prisms of four, eight, or more sides, with 
 pyramidal terminations, and often bent as in 
 the figure; 1A1=123° 73’. Crystals often 
 acicular, and penetrating quartz. Some- 
 times massive. Cleavage lateral, somewhat 
 distinct. 
 
 Color reddish-brown to nearly red ; streak 
 very pale brown. Lustre submetallic-ada- 
 mantine. Transparent to opaque. Brittle. 
 H.=6-6°5. G,=—4:15-4:25. 
 
 Composition. TiO,= Oxygen 39, titanium 61 = 100. 
 Sometimes contains iron, and has nearly a black color ; this 
 variety is called Nigrine. B.B. alone unaltered ; with salt 
 of phosphorus a colorless bead, which in the reducing flame 
 becomes violet on cooling, 
 
 Diff. The peculiar subdamantine lustre of rutile, and 
 brownish-red color, much lighter red in splinters, are striking 
 characters, It differs from tourmaline, idocrase, and augite, 
 by being unaltered when heated alone before the blowpipe $ 
 and from tin ore, in not affording tin with soda; from 
 sphene in its crystals. 
 
 
 
 ‘treo Sie Mf 
 
COBALT AND NICKEL. 163 
 
 Obs. Occurs imbedded in granite, gneiss, mica schist sye- 
 nyte, and in granular limestone. Sometimes associated with 
 hematite, as at the Grisons, Yrieix in France, Castile, 
 Brazil, and Arendal in Norway, are some of the foreign 
 localities. 
 
 In the United States, it occurs in crystals in Maine, at 
 Warren; in New Hampshire, at Lyme and Hanover; in 
 Massachusetts, at Barre, Windsor, Shelburne, Leyden, Con- 
 way ; in Connecticut, at Monroe and Huntington ; in New 
 York, near Edenyille, Warwick, Amity, at Kingsbridge, and 
 in Essex County at Gouverneur ; in Pennsylvania, in Chester 
 County; in the District of Columbia, at Georgetown; in 
 North Carolina, in Buncombe County ; in Georgia, in Lin- 
 coln and Habersham counties ; at Magnet Cove in Arkansas, 
 
 The specimens of limpid quartz, penetrated by long aci- 
 cular crystals, are often very handsome when polished. A re- 
 markable specimen of this kind was obtained in Northern 
 Vermont, and less handsome ones are not uncommon ; they 
 are found in North Carolina. Polished stones of this kind 
 are called fléches d’amour (love’s arrows) by the French. 
 
 This ore is employed in painting on porcelain, and quite 
 largely for giving the requisite shade of color and enamel 
 appearance to artificial teeth. 
 
 Octahedrite (Anatase); Brookite. These species have the same com- 
 ‘position as rutile. Octahedrite occurs in slender nearly transparent 
 octahedrons, of a brown color. 1A1=97° 51’. H.=5°5-6. G.=38- 
 3:95. From Dauphiny, the Tyrol, and Brazil; at Smithfield, R. I. 
 
 Brookite is met with in thin hair-brown flat trimetric crystals, at- 
 tached by one edge. Also in thick iron-black crystals, as in the va- 
 riety called Arkansite. H.=5-5-6. From Dauphiny; Snowdon in 
 Wales; Ellenvilie, Ulster County, N. Y. ; Paris, Maine ; gold wash- 
 ings of North Carolina ; Magnet Cove, Arkansas (Arkansite). 
 
 Perofskite. In cubic crystals, of yellow, brown, and black colors ; 
 chemical formula (Ti, Ca), O,. From the Urals, the Tyrol, and Magnet 
 Cove, Arkansas. 
 
 Besides the ores here described, titanium is an essential constituent 
 also of ilmenite (titanic iron), and of the silicates titanite or sphene 
 (p. 290), keilhawite (p. 291), warwickite ; and occurs also in the zir- 
 conia and yttria ores eschynite, erstedite, and polymignite, and in some 
 other rare species ; sometimes in pyrochlore, 
 
 COBALT. NICKEL. 
 
 Cobalt has not been found native. The ores of cobalt 
 are sulphides, arsenides, arseno-sulphides, an oxide, a car- 
 bonate, a phosphate, and an arsenate; and nickel is often 
 
164 DESCRIPTIONS OF MINERALS. , 
 
 associated with cobalt in the sulphides and arsenides. The 
 ores having a metallic lustre vary in specific gravity from 
 6-2 to 7-2; and the color is nearly tin-white or pale steel_ 
 gray, inclined to copper-red. The ores without a metallic — 
 lustre have a Clear red or reddish color, and specific gravity 
 of nearly 3. Cobalt is often present also in arsenopyrite (or 
 mispickel), and sometimes in pyrite. 
 
 The ores of nickel are sulphides, arsenides, arseno-sulph- 
 ides, and antimono-sulphides, a sulphate, carbonate, silicates, 
 arsenate; and the metal is a constituent of several cobalt 
 ores, and also often of pyrrhotite (magnetic pyrites). Specific 
 gravity between 3 and 8; hardness of one 38, but mostly be- 
 tween 5and6. Those of metallic lustre resemble some cobalt 
 ores ; but they do not give a deep blue color with borax. 
 
 Linnzite.—Cobalt Sulphide. Cobalt and Nickel Sulphide. 
 
 Isometric. In octahedrons and cubo-octahedrons ; also 
 massive. Color pale steel-gray, tarnishing copper red. Streak 
 blackish gray. H.=5°9. G. =4'8-5. 
 
 Composition. Co,8,= Sulphur 42:0, cobalt 5°80=100 ; but 
 with part of the cobalt replaced by nickel; copper some- 
 times present. Siegenite is a variety containing 30 to 40 per 
 cent. of nickel. B.B. on charcoal yields sulphurous odor 
 and a magnetic globule ; often also arsenical fumes. 
 
 Obs. From Sweden, Prussia ; Mine la Motte in Missouri 
 (Siegenite) ; Mineral Hill in Maryland. Sometimes called 
 cobalt pyrites. , 
 
 Millerite.—Nickel Sulphide. Capillary Pyrites. 
 
 Rhombohedral. Usually in capillary or needle-like crys- 
 tallizations ; sometimes like wool. Also in columnar crusts 
 and radiated. Color brass-yellow, inclining to bronze-yellow, 
 with often a gray iridescent tarnish. Streak bright. Brittle. 
 H.==3-5) mye chs =4°6-5°65. 
 
 Composition. Ni S=Sulphur 35-6, nickel 64°4=100. In 
 the open tube sulphurous fumes. B.B. on charcoal fuses 
 to a globule; and after roasting, gives, with borax and salt of 
 phosphorus, a violet bead in O.F., which in R.F. becomes 
 gray from reduced metallic nickel. | 
 
s 
 
 COBALT AND NICKEL. 165 
 
 Obs. From Joachimstahl, Przibram, Riechelsdorf; Sax- 
 ony ; Cornwall ; at the Sterling Mine, Antwerp, N. Y.; at 
 the Gap Mine, Lancaster Co., Pa.; at St. Louis, Mo., in 
 capillary forms, and sometimes wool-like, in cavities in mag- 
 nesian limestone. A valuable ore of nickel. 
 
 Beyrichite has the formula Ni, §,. 
 
 Smaltite.—Cobalt Glance. Chloanthite. 
 
 Tsometric. Occurs in octahedrons, cubes, and dodecahe- 
 drons, and other forms. See figs. 1, 2, 3, page17, and 17, 27, 
 page 20. Cleavage octahedral, somewhat distinct. Also 
 reticulated ; often massive. 
 
 Color tin-white, sometimes inclining to steel-gray. Streak 
 grayish black. Brittle. Fracture granular and uneven. 
 H.=5°5-6. G.=6°4-7°2. 
 
 Composition. (Co, Ni) As,; the ore being either a cobalt 
 arsenide, or cobalt-nickel arsenide; and graduating into the 
 nickel arsenide called Chioanthite. 'The cobalt in the ore 
 may constitute 23°5 per cent. ; but it may be wholly absent 
 as in the chloanthite. In addition, iron often replaces part 
 of the other metals, as in the variety Safflorite. 
 
 In the closed tube gives a sublimate of metallic arsenic ; 
 in the open tube a white sublimate of arsenous oxide, and 
 sometimes traces of sulphurous acid. B.B. on charcoal, 
 affords an arsenical odor, fuses to a globule which gives re- 
 action for iron, cobalt, and nickel. 
 
 Diff. Arsenopyrite (mispickel) has tho white color of 
 smaltite, but it yields sulphur as well as arsenic, and in a 
 closed tube affords arsenic sulphide, orpiment and realgar. 
 
 Obs. Usually in veins with ores of cobalt, silver, and 
 copper. Occurs in Saxony, especially at Schneeberg ; also 
 in Bohemia, Hessia, and Cornwall. 
 
 In the United States it is found in gneiss with copper 
 nickel (niccolite), at Chatham, Conn. 
 
 Cobaltite. 
 
 Isometric. Crystals like those of pyrite, but silver-white 
 in color with a tinge of red, or inclined to steel-gray. Streak 
 grayish black. Brittle. H.=5°5. G.=6°63. 
 
 Composition. CoS,+CoAs,=CoAsS=Arsenic 45:2, sul- 
 phur 29°3, cobalt 35°5=100, but_often with much iron 
 and occasionally a little copper. Unaltered in the closed 
 
166 DESCRIPTIONS OF MINERALS. 
 
 tube ; but in the open tube, yields sulphurous fumes and a 
 white sublimate of arsenous oxide. B.B. on charcoal yields 
 sulphur and arsenic and a magnetic globule ; with borax a 
 cobalt-blue globule. 
 
 Diff. Unlike smaltite affords sulphur, and has a reddish 
 tinge in its white color. 
 
 Obs. From Sweden, Norway, Siberia, and Cornwall. 
 Most abundant in the mines of Wehna in Sweden, first 
 opened in 1809. 
 
 Niccolite.—Copper Nickel. Arsenical Nickel. 
 
 Hexagonal. Usually massive. Color pale copper-red. 
 Streak pale brownish-red. Lustre metallic. Brittle. ie 
 5-55. G.=7°3-7 sae 
 
 Composition. Ni As=Nickel 44, and arsenic 563; some- 
 times part of the arsenic is replaced by antimony. Gives off 
 arsenical (alliaceous) fumes before the blowpipe, and fuses to 
 a pale globule, which darkens on exposure. Assumes a 
 green coating in nitric acid, and is dissolved in aqua-regia. 
 
 Diff. Distinguished from pyrite and linneeite by its pale 
 reddish shade of color, and also its arsenical fumes, and 
 from much of the latter by not giving a blue color with 
 borax. None of the ores of silver with a metallic lustre 
 have a pale color, excepting native silver itself. 
 
 Obs. Accompanies cobalt, silver, and copper ores in the 
 mines of Saxony, and other parts of Europe; also sparingly 
 in Cornwall. 
 
 It is found at Chatham, Conn., in gneiss, associated with 
 white nickel or cloanthite. 
 
 Skutterudite. A cobalt arsenide of the formula Co As,, from Skut- 
 terud, Norway. 
 
 Breithauptite or Antimonial Nickel. NiSb=Antimony 67 ‘8, nickel 
 32-2—100. It has a pale copper-red color, inclining to violet. H.=5'5 
 -6. G.=7'54. Crystals hexagonal. From Andreasberg. 
 
 Gersdorffite. A nickel arsenosulphide; NiS,+NiAs,=Ni AsS= 
 Arsenic 45°5, sulphur 19°4, nickel 35°1, but varying much in composi- 
 tion. Color sulphur-white to steel-gray. H.=5°5. G.=5°6-6'9. 
 
 Ullmannite or Nickel Stibine. An antimonial nickel sulphide, con- 
 taining 25 to 28 per cent. of nickel. Color steel-gray, inclining to sil- 
 ver-white. In cubical crystals, and also massive. H.=5-5'5. G.=6"40. 
 From the Duchy of Nassau. 
 
 Grimmauite or Bismuth Nickel. A sulphide containing 31 to 38°5 of 
 sulphur, 10 to 14 per cent. of bismuth, with 22 to 407 of nickel. 
 Color light steel-gray to silver-white ; often tarnished yellowish. H.= 
 4-5. G.=5'13. From the district of Altenkirchen, Prussia. | 
 
COBALT AND NICKEL. 16% 
 
 Asbolite.—EHarthy Cobalt. Black Cobalt Oxide. 
 
 Earthy, massive. Color black or blue-black. Soluble in 
 muriatic acid, with an evolution of fumes of chlorine. | 
 
 Obs. Occurs in an earthy state mixed with oxide of man- 
 ganese as a bog ore, or secondary product. Abundant at 
 Mine La Motte, Missouri, and also near Silver Bluff, South 
 Carolina. ‘The analyses vary in the proportion of oxide of 
 cobalt associated with the manganese, as the compound is a 
 mere mixture. Sulphide of cobalt occurs with the oxide. 
 The Carolina ores afforded Cobalt oxide 24, manganese 
 oxide 76. The ore from Missouri, as analyzed by Prof. 
 Silliman, afforded 40 per cent. of cobalt oxide, with oxides 
 of nickel, manganese, iron and copper. 
 
 This ore has been found abroad in France, Germany, 
 Austria, and England. 
 
 The ore is purified and made into smalt, for the arts. 
 
 Erythrite—Cobalt Bloom. Hydrous Cobalt Arsenate. 
 
 Monoclinic. In oblique crystals having a highly perfect 
 cleavage, like mica; lamine flexible in one direction. Also 
 as an incrustation, and in reniform shapes, sometimes stel- 
 late. 
 
 Color, peach-red, crimson-red, rarely grayish or greenish ; 
 streak a little paler, the dry powder lavender-blue. Lustre 
 of lamin pearly; earthy varieties without lustre. Trans- 
 parent to subtranslucent. H.=1°5-2. G.=2.95. 
 
 Composition. Co; 0, As,+8aq=Arsenic acid 38:4, oxide 
 of cobalt 37:6, water 24:0. B.B. on charcoal gives arsen- 
 ical fumes and fuses; yields a blue glass with borax. 
 
 The earthy ore is sometimes called peach-blossom ore, from 
 its color; and also red cobalt ochre. Kéttigite is a kind 
 containing zinc. 
 
 Diff. Resembles red antimony, but that species wholly 
 volatilizes before the blowpipe. From red copper ore it 
 differs in giving a blue glass with borax; moreover, the 
 color of the copper ore is more sombre. 
 
 Obs. Occurs with ores of lead and silver, and other co- 
 balt ores. Schneeberg, in Saxony; Saalfield, in Thuringia; | 
 and Riechelsdorf, in Hegsia, are noted European localities. 
 It is found also in Dauphiny, Cornwall, and Cumberland, 
 
 Valuable as an ore of cobalt when abundant. 
 
168 DESCRIPTIONS OF MINERALS. 
 
 Roselite is a rose-red triclinic arsenate of cobalt. 
 
 Biebertie or Cobalt Vitwiol. as a flesh-red or rose-red tint, and 
 astringent taste. CoO,S-+-7aq = Sulphuric acid 28:4, cobalt oxide 
 25°5, water 46:1. 
 
 Morenosite. A nickel vitriol, NiO,S+%7aq, having apple-green to 
 greenish-white color. Lindackerite, hydrous nickel-copper arsenate. 
 
 Zaratite or Emerald Nickel. Incrusting, minute globular or stalac- 
 titic. Color bright emerald-green. Lustre vitreous. ‘Transparent or 
 nearly so. H.=8-3°25. G.=2°5-2'7. It is a nickel carbonate, con- 
 taining nearly 80 per cent. of water. B.B. infusible alone, but loses 
 its color. Occurs with chromic iron and magnesium carbonate on 
 serpentine, in Lancaster County, Pennsylvania. 
 
 Remingtonite. A hydrous nickel carbonate, rose-colored, from 
 Finksburg, Md. ; 
 
 Spherocobaltite. A cobalt carbonate, Co O,C, from Saxony. 
 
 Nickel Silicates. Genthite is a hydrous magnesium and nickel sili- 
 cate, of a pale apple-green color, yielding in one analysis 30 per cent. 
 of nickel oxide. From Texas,’ Lancaster County, Pa., and other 
 localities. Réttisite, from Rottis, Voigtland, is similar. Pimedlite is 
 an impure apple-green silicate, affording in one case 15°6 per cent. of 
 nickel oxide. Alipite is similar; so also Garnierite (and Noumeite), 
 from New Caledonia, and worked there for nickel. 
 
 General Remarks.—The two arsenical ores of cobalt afford the 
 greater part of the cobalt of commerce, The earthy oxide when 
 abundant is a profitable source of the metal. Erythrite (Cobalt 
 Bloom) occurs abundantly with other cobalt ores at its localities in 
 Saxony, Thuringia and Hesse Cassel. Arsenopyrite (mispickel) yields 
 at times 5 to 9 per cent. of cobalt. Cobalt is never employed in 
 the arts in a metallic state, as its alloys are brittle and unimpor- 
 tant. It is chiefly used for painting porcelain and pottery, and is 
 required for this purpose in the state of an oxide, or the silicated 
 oxide called smalt and azure. Zaffreis an impure oxide obtained in 
 the calcining of the ore with twice its weight of sand; and from it 
 the smalt and azure are produced. Nickel is worked in Germany, 
 Austria, Russia, Sweden, England, United States, and New Caledonia. 
 It is obtained largely from the copper nickel (niccolite) and chloan- 
 thite, or from an artificial product called speiss (an impure arsenide), 
 derived from roasting ores of cobalt containing nickel ; from siegenite 
 (or nickel-linnzite), a sulphide of cobalt and nickel ; from millerite), 
 in part ; from the apple-green silicate ; and largely from pyrrhotite 
 or ‘‘magnetic iron pyrites.” Atthe Gap Mine, near Lancaster, Pa., 
 the ore is millerite and pyrrhotite ; in Missouri, the siegenite; in 
 New Caledonia, chiefly the silicate. . 
 
 Nickel also occurs in meteoric iron, forming an alloy with the iron, 
 which is characteristic of most meteorites. The proportion sometimes 
 exceeds 20 per cent. 
 
 As nickel does not rust or oxidize (except when heated), it is supe- 
 rior to steel for the manufacture of many philosophical instruments. 
 Aa alloy of copper, nickel, and zinc (one-sixth to one-third nickel), 
 constitutes the German silver, or argentane. 
 
 ‘German silver” is not a very recent discovery. In the reign of 
 William III., an act was passed making it felony to blanch copper in 
 
URANIUM. 169 
 
 imitation of silver, or mix it with silver for sale. ‘‘ White copper” 
 has long been used in Saxony for various small articles; the alloy 
 employed is stated to consist of copper 88:00, nickel 8°75, sulphur 
 with a little antimony 0°75, silex, clay, and iron 1°75. A similar 
 alloy is well known in China, and is smuggled into various parts of 
 the Hast Indies, where it is called packfong. It has been sometimes 
 identified with the Chinese tutenague. M. Meurer analyzed the white 
 copper of China, and found it to consist of copper 65°24, zinc 19°52, 
 nickel 138, silver 25, with a trace of cobalt and iron. Dr. Fyfe ob- 
 tained copper 40°4, nickel 31:6, zinc 25°4, and iron 2°6. It has the 
 color of silver, and is remarkably sonorous. It is worth in China 
 about one-fourth its weight of silver, and is not allowed to be carried 
 out of the empire. 
 
 An alloy of 88 per cent. copper and 12 per cent. nickel is the mate- 
 rial of the United States cent, introduced in 1851. Switzerland, Bel- 
 gium and Jamaica also have used a nickel alloy for coins. 
 
 Nickel is mostly used at the present time for nickel-plating by 
 electro-deposition. The value of the metal in commerce rose in the 
 years 1870 to 1875, from $1.25 to $3.00 per pound, The amount 
 annually produced is about 600 tons. 
 
 URANIUM. 
 
 Uranium ores have a specific gravity not above 7, and a 
 hardness below 6. The ores are either of some shade of light 
 green or yellow, or they are dark brown or black and dull, or 
 submetalic and without a metallic lustre when powdered. 
 They are not reduced when heated with carbonate of soda 5 
 and the brown or black species fuse with difficulty on the 
 edges or not at all. 
 
 Uraninite.—Pitchblende. Uranium Oxide. 
 
 Isometric. In octahedrons and relatedforms. Also mas- 
 sive and botryoidal. Color grayish, brownish, or velvet- 
 black. Lustre submetallic or dull. \ Streak black. Opaque. 
 Peo oe Ge 47, 
 
 Composition. 5 to 8% per cent. of uranium oxides with 
 silica, lead, iron, and some other impurities. Related to 
 the spinel group. B.B. infusible alone; a gray scoria with 
 borax. Dissolves slowly in nitric acid, when powdered. 
 
 Obs. Occurs in veins with ores of lead and silver in 
 Saxony, Bohemia, and Hungary; also in the tin mines of 
 Cornwall, near Redruth. In the United States, very spar- 
 ingly at Middletown, Redding, and Haddam, Conn.; in North 
 Carolina ; on the north side of Lake Superior (Coracite). 
 
170 DESCRIPTIONS OF MINERALS. 
 
 The oxides of uranium are used in painting upon porce- 
 lain, yielding a fine orange in the enameling fire, and a 
 black color in that in which the porcelain is baked. 
 
 Cleveite. Hydrated oxide of uranium, iron, erbium, cerium, yttrium, 
 in cubic forms. From Norway. ; 
 
 Gummite. An amorphous uranium ore, looking like gum, of a red- 
 dish or brownish color. It is a hydrous uraninite, and has resulted 
 from its alteration. Occurs at Johanngeorgenstadt, and in North Caro- 
 lina, 
 
 Eliasite. Another hydrous ore, more or less resin-like in aspect, of 
 a reddish-brown to black color. 
 
 Hatchettolite. A hydrous columbo-tantalate of uranium, in isome- 
 tric octahedrons, resembling pyrochlore from North Carolina. — 
 4°76-4°84. 
 
 Blomstrandite. A hydrous titano-columbate, from Sweden. 
 
 Torbernite.—Uranite. Chalcolite. Uran-Mica. 
 
 Dimetric. In square tables, thinly foliated parallel to the 
 base, almost like mica; laminz brittle. 
 
 Color emerald and grass-green; streak a little paler. 
 Lustre of laminz pearly. ‘Transparent to subtranslucent. 
 H. =2-2°5. G.=3°4-3°6. . 
 
 Composition. A uranium-copper phosphate, consisting if 
 pure of Phosphorus pentoxide 15:1, uranium trioxide 61°2, 
 copper oxide 8°4, water 15°3=100. B.B. fuses to a blackish 
 mass, and colors the flame green. 
 
 Diff. The micaceous structure, connected with the bright 
 green color and square tabular form of the crystals, are strik- 
 ing characters. ‘The folia of mica are not brittle, like those 
 of uranite. ; 
 
 Obs. Occurs with uranium, silver and tin ores. It is 
 found at St. Symphorien, in splendid crystallizations, near 
 Redruth and elsewhere in Cornwall; in the Saxon and 
 Bohemian mines; in North Carolina. 
 
 Autunite is similar to torbernite ; but has a bright citron-yellow 
 color, and is a uranium-calcium_ phosphate. From the same mining 
 regions, also from near Autun in France, and sparingly, from Portland, 
 Middletown, and Redding, Conn.; Acworth, N. H.; Chesterfield, Mass. ; 
 and in North Carolina, 
 
 Uranospinite is an autunite containing arsenic instead of phos- 
 phorus; and Zewnerite is a torbernite containing arsenic instead of 
 phosphorus. 
 
 Samarskite (formerly named wranotantalite and yttroilmenite) is a 
 compound of oxyd of uranium with columbic and tungstic acids, from 
 Miask in the Ural. It is of a dark brown color and submetallic lustre. 
 H=5°. G.=5:4-5'7. Abundant in North Carolina, 
 
IRON. aig) 
 
 Johannite or Uranvitriol is a sulphate of uranium. It has a fine 
 emerald-green color, and a bitter taste. From Bohemia. 
 
 Trégerite and Walpurgite are uranium arsenates. Voglite and 
 Liebigite are uranium carbonates. Johannite is a uranium vitriol ; 
 Uranochalcite, Medijdite, Zippeite, Voglianite, Uraconite, are other 
 uranium sulphates. 
 
 Uranocircite is a hydrous barium-uranium phosphate. 
 
 IRON, 
 
 Tron occurs native, and alloyed with nickel in meteoric iron. 
 Its most abundant ores are the oxides and sulphides. It is 
 also found combined with arsenic, forming arsenides and 
 sulpharsenides ; with oxygen and other metals, as chro- 
 mium, aluminum, magnesium ; and in the condition of sul- 
 phate, phosphate, arsenate, columbate, silicate and carbon- 
 ate, of which the last is an abundant and valuable ore. 
 Its ores are widely disseminated. ‘The oxides and silicates 
 are the ordinary coloring ingredients of soils, clays, earth and 
 many rocks, tinging them red, yellow, dull green, brown 
 and black. | 
 
 The ores have a specific gravity below 8, and the ordinary 
 workable ores seldom exceed 5. Many of them are infusible 
 before the blowpipe, and nearly all minerals containing iron 
 become attractable by the magnet after heating, when not 
 so before. By their difficult fusibility, the species with a 
 metallic lustre are distinguished from ores of silver and cop- 
 per, and also more decidedly from these and other ores by 
 blowpipe reaction. 
 
 Native Iron. 
 
 Isometric. Usually massive with octahedral cleavage. 
 
 Color and streak iron-gray. Fracture hackly. Malleable 
 and ductile. H.=4:°5. G.=7:3-7°8. Acts strongly on the 
 magnet. 
 
 Obs. Native iron occurs in grains disseminated through 
 some doleryte, basalt, and other related igneous rocks ; and 
 in Greenland, in very large masses in such igneous rocks, 
 the largest weighing over a ton. It is suggested by J. 
 Lawrence Smith, that the iron was reduced by means of 
 
 carbohydrogen vapors, taken into the rock from carbonaceous 
 rocks passed through on the way to the surface. 
 
172 DESCRIPTIONS OF MINERALS. 
 
 It is a constituent of nearly all meteorites, and the chief 
 ingredient in a large part of them ; and in this state it is 
 with a rare exception alloyed with nickel, and with traces 
 of cobalt and copper. The ‘Texas meteorite, of Yale College, 
 weighs 1,635 pounds ; the Pallas meteorite, now at Vienna, 
 originally 1,600; but one in Mexico, the San Gregorio 
 meteorite, is stated to weigh five tons ; and one in the dis- 
 trict of Chaco-Gualamba, 8. A., nearly fifteen tons. Meteoric 
 iron often has a very broad crystalline structure, long lines 
 and triangular figures being developed by putting nitric acid 
 on a polished surface. ‘The coarseness of this structure dif- 
 fers in different meteorites, and serves to distinguish speci- 
 mens not identical in origin. Nodules of troilite (FeS), 
 and schreibersite (iron phosphide) are common in iron me- 
 teorites. Meteoric iron may be worked like ordinary malle- 
 able iron. The nickel diminishes the tendency to rust. But 
 some kinds contain iron chloride, or are open in texture, and 
 rust badly. 
 
 Pyrite.—Iron Pyrites. Iron Bisulphide. 
 
 30 
 ey 
 
 Isometric. Usually in cubes, the strize of one face at right 
 angles with those of either adjoining face, as in fig. 1. Also 
 
 
 
 
 
IRON. 173 
 
 figs. 2 to 7; also figs. 8 to15 on page 6. Fig. 6, a pentag- 
 onal dodecahedron, isa common form. Occurs also in imi- 
 tative shapes, and massive. 
 
 - Color bronze-yellow ; streak brownish black. Lustre of 
 crystals often splendent metallic. Brittle. H.=6-6°5, be- 
 ing hard enough to strike fire with steel. G.=4:8-5:1. 
 
 Composition. Fe 8, = Sulphur 53°3, iron 46°7= 100. 
 B.B. on charcoal gives off sulphur, and ultimately affords 
 a globule attractable by the magnet. | 
 
 Pyrite often contains a minute quantity of gold, and 
 is then called auriferous pyrite. See under Gold. Nickel, 
 cobalt and copper occur in some pyrite. 
 
 Diff. Distinguished from copper pyrites in being too hard 
 to be cut by a knife, and also in its paler color. The ores 
 of silver, at all resembling pyrite, instead of having its pale 
 bronze-yellow color, are steel-gray or nearly black ; and be- 
 sides, they are easily scratched with a knife and quite fusible. 
 Gold is sectile and malleable. 
 
 Obs. Pyrite is one of the most common ores on the 
 globe. It occurs in rocks of all ages. Cornwall, Elba, 
 Piedmont, Sweden, Brazil, and Peru, have afforded magnifi- 
 cent crystals. Alston Moor, Derbyshire, Kongsberg in Nor- 
 way, are well-known localities. It has also been observed in 
 the Vesuvian lavas, and in many other igneous rocks. 
 
 In the United States, the localities are numerous. Fine 
 crystals have been met with at Rossie, N. Y.; at many 
 other places in that State ; also in each of the New England 
 States and in Canada; in New Jersey, Pennsylvania, Vir- 
 ginia, North Carolina, Georgia, n Colorado, Wyoming and 
 the States west. It occurs in all gold regions, and 1s one 
 source of gold. 
 
 This species is of the highest importance in the arts, 
 although not affording good iron on account of the diffi- 
 culty of separating entirely the sulphur. It affords the 
 greater part of the sulphate of iron (green vitriol or copperas) 
 and sulphuric acid (oil of vitriol) of commerce, and also 
 a considerable portion of the sulphur and alum. To make 
 the sulphate the pyrites is sometimes heated in clay retorts, 
 by which about 17 per cent. of sulphur is distilled over and 
 collected. The ore is then thrown out into heaps, exposed 
 to the atmosphere, when a change ensues by which the re- 
 maining sulphur and iron become through oxidation sul- 
 phate of iron. The material is lixivylated, and partially eva- 
 
174 DESCRIPTIONS OF MINERALS. 
 
 porated, preparatory to its being run off into vats or troughs 
 to crystallize. In other instances, the ore is coarsely broken 
 up and piled in heaps and moistened. Fuel is sometimes 
 used to commence the process, which afterwards the heat 
 generated continues. Decomposition takes place as before, 
 with the same result. Cabinet specimens of pyrite, espe- 
 cially granular or amorphous masses, often undergo a spon- 
 taneous change to the sulphate, particularly when the atmo- 
 sphere is moist. 
 
 Pyrite, owing to its tendency to oxidation, and its very 
 general distribution in rocks of all kinds and ages, is one of 
 the chief sources of the disintegration and destruction of 
 rocks. No granite, sandstone, slate, or limestone, contain- 
 ing it, is fit for architectural purposes or for any outdoor 
 uses. The same destructive effects come from pyrrhotite and 
 marcasite, which also are widely diffused. 
 
 The name pyrites is from the Greek pur, fire, because, as 
 Pliny states, “there was much fire in it,” alluding to its 
 striking fire with steel. This ore is the mundic of miners. 
 
 Marcasite or White iron pyrites. This ore has the same composition as 
 pyrites, but differs in crystallizing in trimetic forms. J /—106° 36. 
 'The color is a little paler than that of pyrite, and it is more liable to 
 decomposition ; hardness the same; specific gravity 46-485. Radi- 
 ated pyrites, Hepatic pyrites, Cockscomb pyrites (alluding to its crested 
 shapes), and Spear pyrites, are names of some of its varieties. It oc- 
 curs in crystals at Warwick and Phillipstown, N. Y. Massive varie- 
 ties are met with at Cummington, Mass.; Monroe, Trumbull, and 
 Kast Haddam, Conn.; and at Haverhill, N. H. ‘ 
 
 Pyrrhotite.—Magnetic Pyrites. Iron Sulphide. 
 
 Hexagonal. Occurs occasionally in hexagonal prisms, 
 which are often tabular; generally massive. 
 
 Color between bronze-yellow and copper-red ; streak dark 
 grayish-black. Brittle H.=385-4°5. G,=4:4—-4:60. 
 Slightly attracted by the magnet. Liable to speedy tarnish. 
 
 Composition. Fe,S,=—Sulphur 395, iron 60°. It is: 
 often a valuable ore of nickel, containing sometimes 3 to 
 5 per cent. of this metal. B.B. on charcoal in the outer 
 flame it is converted into red oxide of iron. In the inner 
 flame it fuses and glows, and affords a black globule which 
 is magnetic, and has a yellowish color on a surface of frac- 
 ture. 
 
 Diff. Its inferior hardness and shade of color, and its 
 
IKON. AZ 
 
 magnetic quality distinguish it from pyrite; and its pale- 
 ness of color from chalcopyrite or copper pyrites. 
 
 Obs. Crystallized specimens have been found at Kongs- 
 berg in Norway, and at Andreasberg in the Hartz. The 
 massive variety is found in Cornwall, Saxony, Siberia, and 
 the Hartz; also at Vesuvius and in meteoric stones. 
 
 In the United States, it is met with at Trumbull and 
 Monroe, New Fairfield, and Litchfield, Conn. ; at Strafford 
 and Shrewsbury, Vt.; at Corinth, New Hampshire; in 
 many parts of Massachusetts and New York; at Lancaster, 
 Pa., where it is worked for nickel. It is used for making 
 green vitriol and sulphuric acid, like pyrite. | 
 
 Troilite is a similar mineral of the formula FeS, occur- 
 ring in meteorites. Schreibersite is a phosphide of iron and 
 nickel, occurring in meteorites. 
 
 Arsenopyrite.—Mispickel. Arsenical Iron Pyrites. 
 Trimetric. In rhombic prisms, with cleavage parallel to 
 the faces J; JAL=111° 40’ to 112°. 
 Crystals sometimes elongated horizon- 
 tally, producing a rhombic prism of 
 
 100° nearly, with J and J the end oe 
 planes. Occurs also massive. 
 Color silver-white; streak dark | If I 
 
 
 
 grayish-black. Lustre shining. Brit- 
 Tita 900-0. . .G.—6'3. 
 
 Composition. Fe AsS= Arsenic 46:0, 
 sulphur 19°6, iron 84:4=100. A co- 
 baltic variety contains 4 to 9 per cent. of cobalt in place 
 of part of the iron; Danaite of New Hampshire, consists 
 of Arsenic 41:4, sulphur 17°8, iron 32°9, cobalt 6:9. B.B. 
 affords arsenical fumes, and a globule of iron sulphide 
 which is attracted by the magnet. In the closed tube a 
 sublimate of arsenic sulphide. Gives fire with a steel and 
 emits a garlic odor. 
 
 Diff. Resembles arsenical cobalt, but is much harder, 
 it giving fire with steel; it differs also in yielding a mag- 
 netic globule before the blowpipe, and in not affording the 
 reaction of cobalt with the fluxes. 
 
 Obs. Arsenopyrite is found mostly in crystalline rocks, and 
 is commonly associated with ores of silver, lead, iron, or cop- 
 
 er. It is abundant at Freiberg, Munzig, and elsewhere in 
 
 urope, and also in Cornwall, England. 
 
176 DESCRIPTIONS OF MINERALS. 
 
 It occurs in crystals in New Hampshire, at Franconia, 
 Jackson, and Haverhill ; in Maine, at Blue Hill Bay, Corinth, 
 Newfield, and Thomaston ; in Vermont, at Waterbury; in 
 Massachusetts, massive at Worcester and Sterling; in Con- 
 necticut, at Chatham, Derby, and Monroe ; in New Jersey, 
 at Franklin; in New York, in Lewis, Essex County, and 
 near Edenville and elsewhere in Orange County ; in Kent, 
 Putnam County. 
 
 Leucopyrite. This is the name of arsenical iron Fe, As,. It re- 
 sembles the preceding in color and in its crystals. I /\, t=3e2* 20; 
 It has less hardness and higher specific gravity. H.=5-0°5. C, =iee 
 -7-4, Contains Iron 32°2, arsenic 66°9, with some sulphur. From 
 Styria, Silesia, and Carinthia. 
 
 Léllingite is another iron arsenide, Fe As,—Arsenic 72°8, iron 27°2 ; 
 specific gravity 6°8-8'71. Berthierite is an iron sulphantimonite. 
 
 Hematite.—Specular Iron Ore. Iron Sesquioxide. 
 
 Rhombohedral. In complex modifications of a rhombohe- 
 
 PR 
 
 dron of 86° 10’ (fig. 1); crystals occasionally thin tabular. 
 Cleavage usually indistinct. Often massive granular ; some- 
 times lamellar or micaceous. Also pulverulent and earthy. 
 
 Color dark steel-gray or iron-black, and often when crys- 
 tallized having a highly splendent lustre ; streak-powder | 
 cherry-red or reddish-brown. The metallic varieties pass 
 into an earthy ore of a red color, haying none of the external 
 characters of the crystals, but perfectly corresponding to them 
 when they are pulverized, the powder they yield being of a 
 deep red color, and earthy or without lustre. G.=4°5-5°3. 
 Hardness of crystals 5-5-6-5. Sometimes slightly attracted 
 by the magnet. 
 
 VARIETIES. ) 
 
 Specular iron. Having a perfectly metallic lustre. 
 
 Micaceous iron. Structure foliated. 
 
 Red hematite. Submetallic, or unmetallic, and of a brown- 
 ish-red color. 4p 
 
 Red ochre. Soft and earthy, and often containing clay. 
 
IRON. re 
 
 Red chalk. More firm and compact than red ochre, and 
 of a fine texture. 
 
 Jaspery clay tron. A hard impure siliceous clayey ore, 
 and having a brownish-red jaspery look and compactness. 
 
 Clay tron stone. 'The same as the last, the color and ap- 
 pearance less like jasper. But this is one variety only of 
 what is called ‘‘clay iron stone,” a name covering also a re- 
 lated variety of siderite and limonite. 
 
 Lenticular argillaceous ore. A red ore, consisting of 
 small flattened grains. 
 
 Martite is hematite in octahedrons, derived, it 1s supposed, 
 from the oxidation of magnetite. 
 
 Composition. Ee O*=Oxygen 30, iron 70=100. BB. 
 alone infusible. Heated in the inner flame it becomes 
 strongly magnetic. 
 
 Diff. The red powder of this ANE and the magnetism 
 which is so easily induced in it by a reduction flame dis- 
 tinguish hematite from all other ores. The word hematite, 
 from the Greek haima, blood, alludes to the color of the 
 powder. 
 
 Obs. This ore occurs in crystalline and stratified rocks of 
 all ages. ‘The more extensive beds of pure ore abound in 
 Archean rocks; while the argillaceous varieties occur in 
 stratified rocks, being often abundant in coal regions and 
 among other strata. Crystallized specimens are found also 
 in some lavas, as a volcanic product. 
 
 Splendid cr ‘ystallizations of this ore come from Elba, whose 
 beds were known to the Romans; also from St. Gothard ; 
 Arendal, Norway ; Longbanshyttan, Sweden ; Lorraine and 
 Dauphiny. Etna and Vesuvius afford handsome specimens. 
 
 In the United States, this is an abundant ore. The two 
 Tron Mountains of Missouri, situated 90 miles south of St. 
 Louis, consist mainly of this ore, piled ‘“in masses of all 
 sizes from a pigeon’s egg to a middle-size church.” One of 
 them is 300 feet high, and the other, the “ Pilot Knob,” is 
 700 fect. The massive and micaccous varieties occur there 
 together with red ochreous ore. Large beds occur in Essex, 
 St. Lawrence and Jefferson counties, N. Y., and at Mar- 
 quette, in Michigan; the micaceous variety, at Hawley, Mass., 
 Piermont, N. H. =! and in Stafford County, Va.; lenticular 
 argillaceous ore abundantly in Oneida, Herkimer, Madison 
 and Wayne counties, N. Y., constituting one or two beds of 
 the Clinton group (Upper Silurian) ,1n a compact sandstone ; 
 
 12 
 
178 DESCRIPTIONS OF MINERALS. 
 
 and the same is found in Pennsylvania and south to Alabama, 
 and also in Wisconsin; it contains 50 per cent. of oxide of 
 iron, with about 25 of carbonate of lime and more or less 
 magnesia and clay. The coal region of Pennsylvania affords 
 abundantly the clay iron ores, but they are mostly either the 
 argillaceous carbonate or limonite. 
 
 Valuable as an iron ore, though less easily worked when 
 pure and metallic than the magnetic and hydrous ores. Pul- 
 verized red hematite is used for polishing metal. Red chalk 
 is a well-known material for red pencils. 
 
 Menaccanite.—IImenite. TitanicIron. Washingtonite. 
 
 Rhombohedral. RAR=85° 31’. Often in thin plates or 
 seams in quartz ; also in grains. Crystals sometimes very 
 large and tabular. 
 
 Golor iron-black ; streak submetallic. Lustre metallic or 
 submetallic. H.=5-6. G.=4%5-5. Acts slightly on the 
 magnetic needle. 
 
 Composition. Like that of hematite, except that part of 
 the iron is replaced by titanium; the amount replaced is 
 very variable. Infusible alone before the blowpipe. 
 
 Diff. Near specular iron, but its powder is not red. 
 
 Ods. Crystals, an inch or so in diameter, occur in War- 
 wick, Amity and Monroe, Orange County, N. Y.; also near 
 Edenville and Greenwood Furnace ; also at South Royalston 
 and Goshen, Mass.; at Washington, South Britain, and 
 Litchfield, Conn. ; at Westerly, Rhode Island. 
 
 It is of no value in the arts and is a deleterious constitu- 
 ent of many iron ores. 
 
 Magnetite.—Magnetic Iron Ore. 
 
 Isometric. Often in octahedrons (fig. 12), and dodecahe- 
 2. 
 
 1 drons (fig. 13). Cleavage octahe- 
 ; dral ; sometimes distinct. Also 
 granularly massive. Occasionally 
 in dendritic forms between the 
 
 folia of mica. 
 Coloriron-black. Streak black. 
 Brittle. H.—5°5-6°. Ge 
 5:1. Strongly attracted by the 
 magnet, and sometimes haying polarity. 
 Composition. Ke#e O,=FeO+Fe 0,=Oxygen 27°6, iron 
 
 
 
IRON. 179 
 
 %2:4—100, Infusible before the blowpipe. Yields a yellow 
 . glass when fused with borax in the outer flame. 
 
 Diff. The black streak and strong magnetism distinguish 
 this species from the following. 
 
 Obs. Magnetic iron ore occurs in extensive beds, and also 
 in disseminated crystals. It is met with in granite, gneiss, 
 mica schist, clay slate, syenyte, hornblende and chlorite 
 schist ; and also sometimes in limestone. | 
 
 The beds at.Arendal, and nearly all the Swedish iron ore, 
 consist of massive magnetic iron. At Dannemora and the 
 Taberg in Southern Sweden, and also in Lapland at Kurun- 
 avara and Gelivara, there are mountains composed of it. 
 
 In the United States it constitutes extensive beds, in Ar- 
 chean rocks, in Warren, Essex, Clinton, Orange, Putnam, 
 Saratoga and Herkimer counties, New York; and in Sussex 
 and Warren counties, in New Jersey. Smaller deposits occur 
 in the several New England States and Canada. Also found 
 at Magnet Cove, in Arkansas; in California, in_ Sierra 
 County, and elsewhere. It exists with hematite in the Iron 
 Mountains of Missouri. 
 
 Masses of this ore, in a state of magnetic polarity, consti- 
 tute what are called lodestones or native magnets. ‘They are 
 met with in many beds of the ore. Siberia and the Hartz 
 have afforded fine specimens; also the Island of Hlba. They 
 also occur at Marshall’s Island, Maine; also near Providence, 
 Rhode Island, and at Magnet Cove, in Arkansas. The 
 lodestone is called magnes by Pliny, from the name of the 
 country, Magnesia (a province of ancient Lydia), where it 
 was found ; and it hence gave the terms magnet and mag- 
 netism to science. 
 
 F'ranklinite. 
 
 Isometric. In octahedral and dodecahedral crystals. Also 
 coarse granular massive. Color iron-black; streak dark 
 reddish-brown. Brittle. H.=5°5-6°5. G.=4°85-5°1. Usually 
 is attracted by the magnet. 
 
 Composition. General formula like that of magnetite, 
 RR O,, but having zinc and manganese replacing part of the 
 iron, as indicated in the formula (Fe, Zn, Mn) (Fe, Mn) O,. 
 A common varicty corresponds to Fe, O,67°6, FeO 58, Zn O 
 6-9, Mn O 9°7=100. 
 
 B.B. with soda on charcoal a zine coating is obtained ; a 
 
180 DESCRIPTIONS OF MINERALS. 
 
 soda bead in the outer flame is colored green by the manga- 
 nese. 
 
 Diff. Resembles magnetic iron, but the exterior color is a 
 more decided black. ‘The streak is reddish brown, and the 
 blowpipe reactions are distinctive. 
 
 Obs. This is an abundant ore at Sterling and Hamburg, 
 in New Jersey, near the Franklin Furnace; at the former 
 place the crystals are sometimes four inches in diameter 5 
 also amorphous at Altenberg, near Aix-la-Chapelle. 
 
 Chromite.—Chromic Iron. 
 
 Isometric. In octahedral crystals, without distinct cleav- 
 age. Usually massive, and breaking with a rough unpolished. 
 surface. 
 
 Color iron-black and brownish black ; streak dark brown. 
 Lustre submetallic ; often faint. H.=5°5. G.=4'3-4°6. 
 In small fragments attractable by the magnet. 
 
 Composition. General formula RR, O,, as for magnetite 5 
 but part of the iron is replaced by chromium. Analysis 
 gives Iron protoxide 382, chromium sesquioxide 68=100 ; 
 aluminum and magnesium also are commonly present in 
 variable amounts, replacing the other constituents. B.B. 
 infusible alone; with borax a beantiful green bead. 
 
 This ore usually possesses a less metallic lustre than the 
 other black iron ores. 
 
 Obs. Occurs usually in serpentine rocks, in imbedded. 
 masses or veins. Some of the foreign localities are the 
 Gulsen Mountains in Styria; the Shetland Islands ; the de- 
 partment of Var in France; Silesia, Bohemia, ete. 
 
 In the United States it is abundant: in Maryland in the 
 Bare Hills, near Baltimore, and also in Montgomery County, 
 at Cooptown, in Harford County ; and in the north part of 
 Cecil County ; occurs also in Townsend and Westfield, Ver- 
 mont, and at Chester and Blandford, Mass. It is also found 
 in Pennsylvania, at Wood’s Mine, near Texas, Lancaster 
 County, in West Branford, Chester County; at Bolton and 
 Ham, Canada East ; in California near New Idria; also in 
 Sonoma County; Tuolumne County, near Crimea House, 
 and elsewhere ; at Seattle in Wyoming. 
 
 The compounds of chromium, which are extensively used 
 as pigments, are obtained chiefly from this ore. Meteorites 
 have afforded a chromium-sulphide, named Daubréelite. 
 
IRON. 181 
 
 Limonite.— Brown Hematite. 
 
 Usually massive, and often with a smooth botryoidal or 
 stalactitic surface, haying a compact fibrous structure with- 
 in. Also earthy. 
 
 Color dark brown and black to ochre-yellow ; streak yellow- 
 ish brown to dull yellow. Lustre sometimes submetallic ; 
 often dull and earthy; on a surface of fracture frequently 
 silky. H.=5-5°5. G.=3-6-4. 
 
 The following are the principal varieties : 
 
 Brown hematite. ‘The botryoidal, stalactitic and asso- 
 ciated compact ore. 
 
 Brown ochre, Yellow ochre. Earthy ochreous varieties, of 
 a brown or yellow color. 
 
 Brown and Yellow clay iron stone. Impure ore, hard and 
 compact, of a brown or yellow color. 
 
 Bog iron ore. A loose earthy ore of a brownish-black 
 color, occurring in low grounds. 
 
 Composition. FeO, H,(=2 Fe 0,+3 H, 0)=Iron sesqul- 
 oxide 85°6, water 14:4=100; or it is a hydrous iron ses- 
 quioxide, containing, when pure, about two-thirds its weight 
 of pureiron. B.B. blackens and becomes magnetic; with 
 borax in the outer flame a yellow glass. 
 
 Diff. This is a much softer ore than either of the two 
 preceding, and is peculiar in its frequent stalactitic forms, 
 and in its affording water when heated in a glass tube. 
 
 Obs. Occurs connected with rocks of all ages, but ap- 
 pears, as shown by the stalactitic and other forms, to have 
 resulted in all cases from the decomposition of other iron 
 ores. 
 
 An abundant ore in the United States. Extensive beds 
 exist in Salisbury and Kent, Conn., also in the neighboring 
 towns of Beekman, Fishkill, Dover, Amenia, N. Y.; also in 
 a similar situation north, in Richmond and West Stock- 
 bridge, Mass.; also in Bennington, Monkton, Pittsford, 
 Putney, and Ripton, Vermont. Large beds are found in 
 Pennsylvania, the Carolinas, near the Missouri Iron Moun- 
 tains, and also in Tennessee, Iowa and Wisconsin. 
 
 This is one of the most valuable ores of iron. The limo- 
 nite of Western New England, and that along the same 
 range geologically in Dutchess County, New York, Eastern 
 Pennsylvania, and beyond, is remarkably free from phos- 
 phorus, and hence is highly valued for its iron. Bog ores 
 
182 DESCRIPTIONS OF MINERALS. 
 
 usually contain much phosphorus, from organic sources, 
 and hence the iron afforded is best fitted for castings. Li- 
 monite is also pulverized and used for polishing metallic 
 buttons and other articles. As yellow ochre, it is a common 
 material for paint. 
 
 _ Gothite (Pyrrhosiderite, Lepidokrokite) is another iron hydrate, often 
 in prismatic crystals, as well as fibrous and massive, of the formula Fe 
 O, H,(=Ee O,+H, 0), and G.=4:0-4°4. 
 
 Turgite has the formula FeO, H,.=—2 Fe 0,+H, 0. Xanthosiderite 
 and (imnite are other related hydrates. 
 
 Melanterite.——Copperas. Iron Vitriol. Green Vitriol. 
 
 Monoclinic. In acute oblique rhombic prisms. JA JI= 
 82° 21’; OA 1=80° 37’. Cleavage parallel to O perfect. 
 Generally pulverulent or massive. 
 
 Color greenish to white. Lustre vitreous. Subtranspa- 
 rent to translucent. Taste astringent, sweetish, and metal- 
 lice. Brittle - Hi = 2) sree: 
 
 Composition. FeO,8+'%aq=Sulphur trioxide 28:8, iron 
 protoxide 25:9, water 45°3=100. B.B. becomes magnetic. 
 Yields’ glass with borax. On exposure, becomes covered 
 with a yellowish powder, which results from oxidation. 
 
 Obs. This species is the result of the decomposition of 
 pyrite and pyrrhotite, which readily afford it 1f moistened 
 while exposed to the atmosphere, and it is obtained from 
 these sulphides for the arts (p. 173). An old mine near 
 Goslar, in the Hartz, is a noted locality. 
 
 Copperas is much used by dyers and tanners, on account 
 of its giving a black color with tannic acid, an ingredient in 
 nutgalls and many kinds of bark. It for the same reason 
 forms the basis of ordinary ink, which is essentially an in- 
 fusion of nutgalls and copperas. It is also employed in the 
 manufacture of Prussian blue. With potasstum ferrocya- 
 nide, any soluble salt of iron sesquioxide, even in minute 
 quantity, gives a fine blue color to the solution (due to the 
 formation of Prussian blue), and this is a delicate test of the 
 presence of iron. : 
 
 Coquimbite, Copiapite, Voltarte, Raimondite, Botryogen, Fibroferrite, 
 Ihleite, are names of other hydrous iron sulphates ; and Halotrichite 
 is an iron-alum. 
 
 Jarosite is a hydrous iron-potash sulphate. 
 
 Pisanite is an iron-copper vitriol. 
 Lagonite. A hydrous iron borate, from the Tuscan lagoons. 
 
IRON. 183 
 
 Wolframite.—Wolfram. Iron-Manganese Tungstate. 
 
 Monoclinic. Sometimes pseudomorphous in octahedrons 
 formed by the alteration of tungstate of hme. Also massive. 
 Color dark grayish-black; streak dark reddish-brown. 
 Lustre submetallic, shining, or dull, H.=5-5°. G.= 
 V:1-7°5. | 
 
 Composition. (Fe,Mn)0,W. A typical variety affords 
 tungsten trioxide 76-47, iron protoxide 9°49, manganese 
 protoxide 14:°04=100. A manganese wolframite has been 
 named Hiibnerite. B.B. fuses easily to a magnetic globule ; 
 with aqua regia dissolved with the separation of yellow 
 tungsten trioxide. 
 
 Found often with tin ores. Occurs in Cornwall, and at 
 Zinnwald and elsewhere in Europe. In the United States it 
 ig found at Monroe and Trumbull, Conn.; on Camdage 
 Farm, near Blue Hill Bay, Me.; near Mine la Motte, Mis- 
 souri; in the gold regions of North Carolina ; in Mammoth 
 Mining district, Nevada Hitbnerite. 
 
 Columbite. 
 
 Trimetric. In rectangular prisms, more or less modified. 
 Also massive. Cleavage parallel to 
 the lateral faces of the prism, some- 
 what distinct. 
 
 Color iron-black, brownish-black 5 
 often with a characteristic iridescence 
 ‘on a surface of fracture; streak dark 
 brown, slightly reddish. Lustre sub- 
 metallic, shining. Opaque. Brittle. 
 H.=5-6. G. —5°4-6'5. 
 
 Composition. Iron columbate, of 
 the formula F O, Cb,=Columbium 
 pentoxide 79°6, iron protoxide 16-4, 
 manganese protoxide 4°4, tin oxide 0°5, lead and copper 
 oxides 0'1—100. Tantalum often replaces part of the 
 columbium, and in this case the mineral is of higher speci- 
 fic gravity. B.B. alone infusible. It imparts to the borax 
 bead the yellow color of iron. 
 
 Diff. Its dark color, submetallic lustre, and a slight iri- 
 descence, together with its breaking readily into angular 
 fragments, will generally distinguish this species from the 
 ores it resembles. 
 
 
 
184 DESCRIPTIONS OF MINERALS. 
 
 Obs. Occurs in granite at Bodenmais in Bavaria, and 
 also in Bohemia. In the United States, it is found in gra- 
 nitic veins, at Middletown and Haddam, Conn. ; at Ches- 
 terfield and Beverly, Mass.; at Acworth, N. H.; Green- 
 field, N. Y. A crystal was found at Middletown, which 
 originally weighed 14 pounds avoirdupois ; and a part of it, 
 6 inches in length and breadth, weighing 6 Ibs. 12 0z., is now 
 in the collections of the Wesleyan University of that place. 
 Also at Standish, Maine; and in granite veins in North 
 Carolina. 
 
 This mineral was first made known from American speci- 
 mens, by Mr. Hatchett, an English chemist, and the new 
 metal it was found to contain was named by him columbium. 
 
 Tantalite. Fe(Mn)O,Ta,. This tantalate of iron is allied to colum- 
 bite. H. 6-65. G. 7-8. It is distinguished by its higher specific 
 gravity. It sometimes contains tin and tungsten. From Finland, 
 Sweden, near Limoges in France, and from North Carolina and 
 Alabama. 
 
 Note.—The metal named Columbium by Hatchett, is the same that 
 has since been called Nioliwm, without any good reason for the change 
 of name. 
 
 Triphylite. An iron manganese-lithium phosphate. See p. 190. 
 
 Vivianite.—Hydrous Iron Phosphate. 
 
 Monoclinic. In modified oblique prisms, with cleavage 
 in one direction highly perfect. Also radiated, reniform, 
 and globular, or as coatings. 
 
 Color deep blue to green. Crystals usually green at right 
 angles with the vertical axis, and blue parallel to it. Streak 
 bluish. Lustre pearly to vitreous. ‘Transparent to translu- 
 cent; opaque on exposure. Thin lamin flexible H.= 
 15-2. G.=2°66. 
 
 Composition. Fe; 0; P,+8aq = Phosphorus pentoxide, 
 28°3, iron protoxide 43°0, water 28°7=100. B.B. fuses 
 easily to a magnetic globule, coloring the flame greenish 
 blue. Affords water in a glass tube, and dissolves in hydro- 
 chloric acid. 
 
 Diff. The deep blue color and the little hardness are 
 decisive characteristics. The blowpipe affords confirma- 
 tory tests. 
 
 Obs. Found with iron, copper and tin ores, and some- 
 times in clay, or with bog iron ore. St. Agnes in Cornwall, 
 Bodenmais, and the gold mines of Véréspatak in Transylva- 
 nia, afford fine crystallizations. In the United States, good 
 
IRON. 185 
 
 erystals have been found at Imlaystown, N. J. At Allentown, 
 Monmouth County, and Mullica Hill, Gloucester County, N. 
 J., are other localities. It often fills the interior of certain 
 fossils. Occurs also at Harlem, N. Y., in Somerset and 
 Worcester counties, Md., and with bog ore in Stafford 
 County, Va. Abundant at Vandreuil in Canada, where it 
 is associated with hmonite. as 
 
 The blue iron earth is an earthy variety, containing about 50 per 
 cent. of phosphoric acid. 
 
 Ludlamite. A clear green hydrous phosphate of iron in monoclinic 
 crystals ; from Cornwall. 
 
 Dufrenite. A hydrous phosphate of iron sesquioxide. It hasa dull 
 green color, and is often found in radiated forms. 
 
 Cacoxenite. Occurs in radiated silky tufts of a yellow or yellow- 
 ish-brown color. H.—3-4. G.=8°38. It is a phosphate of iron 
 sesquioxide, and often contains alumina. It differs from wavellite, 
 which it resembles, in its more yellow color and iron reactions. It 
 also resembles ‘carpholite, but has a deeper color, and does not give 
 the manganese reactions. It occurs on brown iron ore in Bohemia. 
 
 Chalcosiderite and Andrevusite are other iron phosphates. 
 
 Strengite. A hydrous iron phosphate related in formula to scoro- 
 dite. From near Giessen. 
 
 Arsenates of Iron. 
 
 Pharmacosiderite, or Cube ore. Occurs in cubes of dark green to 
 brown and red colors. Lustre adamantine, not very distinct. Streak 
 greenish”or brownish. H.=2°5. G.=8. It is a hydrous arsenate of 
 iron sesquioxide, containing 48 per cent. of arsenic pentoxide. From 
 the Cornwall mines ; also from France and Saxony. 
 
 Scorodite. Crystallizes in rhombic prisms, with an angle of 120° 10’ 
 between its secondary prismatic planes. Color pale leek-green or liver 
 brown. Streak uncolored. Lustre vitreous to subadamantine. Sub- 
 transparent to nearly opaque. H.=3°5-4. G.=38-1-33. A hydrous 
 arsenate of iron sesquioxide, containing 50 per cent. of arsenic pen- 
 toxide. From Saxony, Carinthia, Cornwall, and Brazil; and minute 
 crystals near Edenville, N. Y., with arsenical pyrites. The name of 
 this species is from the Greek skorodon, garlic, alluding to the odor 
 before the blowpipe. Jron sinter is an amorphous form of the same 
 mineral. 
 
 Arseniosiderite is another iron arsenate. 
 
 Siderite.—Spathic Iron. Iron Carbonate. 
 
 Rhombohedral. In rhombohedrons with easy cleavage 
 parallel to a rhombohedron of 107°. Faces often 
 curved. Usually massive, with a foliated struc- 
 ture, somewhat curving. Sometimes in globular 
 concretions or implanted globules. [2 
 
 Color light grayish to brown; often dark ~ 
 brownish-red. It becomes nearly black on ex- 
 
 
 
185 DESCRIPTIONS OF MINERALS. 
 
 posure. Streak uncolored. Lustre pearly to vitreous. Trans- 
 lucent to nearly opaque. H.=3-4°5. G.=3°7-3°9. 
 
 Composition. Fe O;0=Carbon dioxide 37:9, iron protox- 
 ide 62:1—100. Often contains some manganese oxide or 
 magnesia, and lime replacing part of the iron protoxide. 
 Before the blowpipe it blackens and becomes magnetic ; but 
 alone it is infusible. Dissolves in heated hydrochloric acid 
 with effervescence. 
 
 The ordinary crystallized or foliated variety 1s called 
 spathic or sparry iron, because the mineral has the aspect 
 of aspar. he globular concretions found in some amygda- 
 loidal rocks have been called spherosiderite because of its 
 spheroidal forms. An argillaceous variety occurring in nod- 
 ular forms is often called clay iron stone, and is abundant 
 in coal measures. | 
 
 Diff. This mineral cleaves like calcite and dolomite, but 
 it has a much higher specific gravity. It readily becomes 
 magnetic before the blowpipe. Heated in a closed glass 
 tube it gives off carbon dioxide, and becomes magnetic. ‘This 
 test distinguishes it from other iron ores. 
 
 Obs. Spathic iron occurs in rocks of various ages, and 
 often accompanies metallic ores. The largest deposits are 
 in gneiss and mica schist, and clay slate. It is also abundant 
 in the coal formation principally in the form of clay iron 
 stone. In Styria and Carinthia, it is very abundant in gneiss, 
 and in the Hartz it occurs in graywacke. Cornwall, Alston- 
 moor, and Devonshire are English localities. 
 
 A vein of considerable extent occurs at Roxbury, near 
 New Milford, Conn., in quartz, traversing gneiss; at Ply- 
 mouth, Vt., and Sterling, Mass., it is also abundant. It oc- 
 curs also at Monroe, Conn.; in New York State, in Antwerp, 
 Jefferson County, and in Hermon, St. Lawrence County. 
 The argillaceous carbonate in nodules and beds, 1s_ very 
 abundant in the coal regions of Pennsylvania and the West. 
 
 This ore is employed extensively for the manufacture of 
 iron and steel, 
 
 Mesitite is an iron-and-magnesium carbonate. Ankerite contains in 
 addition a large percentage of calcium. Like siderite in crystalliza- 
 tion and cleavage. 
 
 General Remarks.—The metal iron has been known from the most 
 remote historical period, but was little used until the last centuries be- 
 fore the Christian era. Bronze, an alloy of copper and tin, was the 
 almost universal substitute, for cutting instruments as well as weapons 
 
IRON. 187 
 
 of war, among the ancient Egyptians and earlier Greeks ; and even 
 among the Romans (as proved by the relics from Pompeii), and also 
 throughout Europe, it continued long to be extensively employed for 
 these purposes. 
 
 The Chalybes, bordering on the Black Sea, were workers in iron and 
 steel at an early period ; and near the year 500 B.C., this metal was 
 introduced from that region into Greece, so as to become common for 
 weapons of war. From this source we have the expression chulybeate 
 applied to certain substances or waters containing iron. 
 
 The iron mines of Spain have also been known froma remote epoch, 
 and it is supposed that they have been worked ‘‘at least ever since 
 the times of the later Jewish kings; first by the Tyrians, next by the 
 Carthaginians, then by the Romans, and lastly by the natives of the 
 country.” These mines are mostly contained in the present provinces 
 of New Castile and Aragon. Elba was another region of ancient works, 
 <‘inexhaustible in its iron,” as Pliny states, who enters somewhat fully 
 into the modes of manufacture. The mines are said to have yielded 
 iron since the time of Alexander of Macedon. The ore beds of Styria 
 in Lower Austria, were also a source of iron to the Romans. 
 
 The ores from which the iron of commerce is obtained, are the 
 spathic iron or carbonate, magnetic iron, hematite or specular iron, 
 limonite or ‘‘ brown hematite,” and bog iron ore. In England, the prin- 
 cipal ore used is an argillaceous carbonate of iron, called often clay 
 iron stone, found in nodules and layers in the coal measures. It con- 
 sists of carbonate of iron, with some clay, and externally has an earthy, 
 stony look, with little indication of the iron it contains except in its 
 weight. It yields from 20 to 35 per cent. of cast iron. The coal basin 
 of South Wales, and the counties of Stafford, Salop, York, and Derby, 
 yield by far the greater part of the English iron. Brown hematite is 
 also extensively worked. In Sweden and Norway, at the famous 
 works of Dannemora and Arendal, the ore is the magnetic iron ore, 
 and is nearly free from impurities as it is quarried out. It yields 50 to 
 60 per cent. of iron. The same ore is worked in Russia, where it 
 abounds in the Urals. The Elba ore is the specular iron. In Germany, 
 Styria, and Carinthia, extensive beds of the spathic iron are worked. 
 The bog ore is largely reduced in Prussia, 
 
 In the United States, all these different ores are worked. The local- 
 ities are already mentioned. The magnetic ore is reduced in New 
 England, New York, Northern New Jersey, and sparingly in Pennsyl- 
 vania, and other States. Limonite, or brown hematite, is largely 
 worked along Western New England and Eastern New York, in Penn- 
 sylvania, and many States South and West. The earthy argillaceous 
 carbonate like that of England, and the hydrate, are found with the 
 coal deposits, and are a source of much iron. 
 
 The amount of iron manufactured in the world in the year 1873 was 
 14,885,488 tons, of which Great Britain produced _6,566,000 tons, 
 United States, 2,561,000 tons, Germany 1,665,000 tons, France 1,381,000 
 tons, Belgium 653,000 tons, Austria with Hungary 425,000 tons, Russia 
 354,000 tons, Sweden 822,000 tons, Luxembourg 300,000 tons. _ 
 
188 DESCRIPTIONS OF MINERALS. 
 
 MANGANESE. 
 
 The common ores of manganese are the oxides, the car- 
 bonate, and the silicates. There are also sulphides, an 
 arsenide, and phosphate. They have a specific gravity be- 
 low 5:2, 
 
 IMianganese Sulphides and Arsenide. 
 
 Alabandite or Manganblende. A manganese sulphide Mn§, of an 
 iron-black color, green streak, submetallic lustre. H.=3°5-4. G.= 
 $°9-4:0. Crystals, cubes and regular octahedrons. From the gold 
 mines of Nagyag, in Transylvania. 
 
 Hauerite. A sulphide, Mn 82, containing twice the proportion of 
 sulphur in the last. Color reddish brown and brownish black, re- 
 sembling blende. H.=4. G.—3°46. From Hungary. 
 
 Kaneite is a manganese arsenide, of a grayish-white color, and 
 metallic lustre, which gives off alliaceous fumes. G.=5'55, From 
 Saxony. 
 
 Pyrolusite.—Manganese Dioxide. 
 
 Trimetric. In small rectangular prisms, more or less 
 modified. JAZ=93° 40’. Sometimes 
 fibrous and radiated or divergent. Of- 
 ten massive and in reniform coatings. 
 
 Color iron-black; streak black, non- 
 metallic. H.=2-25 G.=4°8. 
 
 Composition. Mn O, = Manganese 
 63:2, oxygen 36°83=100. A minute 
 portion of it imparts to a borax bead 
 a deep amethystine color while hot, 
 which becomes red-brown on cooling. It yields no water 
 in a matrass. 
 
 Diff. Differs from psilomelane by its inferior hardness, 
 and from ores of iron by the violet glass with borax. 
 
 Obs. This ore is extensively worked in Thuringia, Mo- 
 ravia, and Prussia. It is common in Devonshire and Somer- 
 setshire, in England, and in Aberdeenshire. In the United 
 States it is associated with the following species in Ver- 
 mont, at Bennington, Brandon, Monkton, Chittenden, and 
 Irasburg ; it occurs also in Maine, at Conway, and Plain- 
 field in Massachusetts ; at Salisbury and Kent, m Conn., 
 on hematite ; on Red Island, in the Bay of San Francisco ; 
 at Pictou and Walton, Nova Scotia; near Bathurst, in 
 New Brunswick. 
 
 
 
MANGANESE. 189 
 
 The name pyrolusite is from the Greek pur, fire, and lwo, 
 to wash, and alludes to its property of discharging the 
 brown and green tints of glass, for which it 1s extensively 
 used. 
 
 Besides the use just alluded to, this ore is extensively em- 
 ployed for bleaching, and for affording the gas oxygen to 
 the chemist. 
 
 Hausmannite. A manganese oxide, 2Mn0+Mn 0,, which contains 
 "2-1 per cent. of manganese, when pure. Brownish black and sub- 
 metallic, occurring massive and in square octahedrons. H.=5-0°0. 
 G.=4:7. From Thuringia and Alsatia. Hetwrolite is a zinc-hausman- 
 nite, from Sterling Hill, N. J. 
 
 Braunite. An oxide of manganese, containing 69 per cent. of man- 
 ganese when pure. Color and streak dark brownish-black, and lustre 
 submetallic. Occurs in square octahedrons and massive. H,=—6-6'0. 
 G.=4'8. From Piedmont and Thuringia. 
 
 Manganite. A hydrous sesquioxide of manganese. Occurs massive 
 and in rhombic prisms. Color steel-black to iron-black. H. =4-4°5. 
 G.=4:3-4:4, From the Hartz, Bohemia, Saxony, and Aberdeenshire. 
 It is found at several points in New Brunswick and Nova Scotia. 
 
 Psilomelane. 
 
 Massive and botryoidal. Color black or greenish-black. 
 Streak reddish or brownish-black, shining. H.=5-6. G.= 
 4—4°4, 
 
 Composition. Essentially manganese dioxide with a little 
 water, and also some baryta or potassa. The compound is 
 somewhat varying in its constitution. Before the blowpipe 
 like pyrolusite, except that it affords water. 
 
 Obs. This is an abundant ore, and is associated usually 
 with the pyrolusite. It occurs at the different localities 
 mentioned under pyrolusite, and the two are often in alter- 
 nating layers; it has been considered an impure variety of 
 the pyrolusite. The name is from the Greek psilos, smooth 
 or naked, and melas, black. 
 
 Pyrochroite. Hydrous manganese protoxide, of white color. From 
 Sweden. MnO, H,. 
 
 Pelagite. The manganese nodules found in many regions over the 
 bottom of the ocean. Affords, according to an analysis, about 40 per 
 cent. of Mn 0O,, 27 FeO,, 13 of water lost at a red heat, along with 14 
 per cent. of silica and 4 of alumina; 24°5 per cent. of water were 
 lost below 100° C. Probably a mixture. 
 
 Chaleophanite. A hydrous oxide of manganese and zinc, in rhombo- 
 hedral crystals and stalactites ; from Sterling Hill, N. J. 
 
190 DESCRIPTIONS OF MINERALS. 
 
 Wad.—Bog Manganese. 
 
 Massive, reniform or earthy ; also in coatings and dendri- 
 tic delineations. Color and streak black or brownish black. 
 Lustre dull, earthy. H.=1-6. G.=3-4. Soils the fingers. 
 
 Composition. Consists of manganese dioxide, in varying 
 proportions, from 30 to 70 per cent., mechanically mixed 
 with more or less of iron sesquioxide, 10 to 25 per cent. of 
 water, and often several per cent. of oxide of cobalt or cop- 
 per. It is formed in low places from the decomposition of 
 minerals containing manganese. Gives off much water 
 when heated, and affords a violet glass with borax. 
 
 Obs. Wad is abundant in Columbia and Dutchess coun- 
 ties, N. Y., at Austerlitz, Canaan Centre, and elsewhere ; 
 also at Blue Hill Bay, Dover, and other places in Maine; 
 at Nelson, Gilmanton, and Grafton, N. H.; and in many 
 other parts of the country. 
 
 It may be employed like the preceding in bleaching, but 
 is too impure to afford good oxygen. It may also be used | 
 for umber paint. 
 
 | Lampadite, or Cupreous Manganese. A wad containing 4 to 18 per 
 cent, of copper oxide. 
 
 Triphylite. 
 
 Trimetric. In rhombic crystals, massive. Color green- 
 ish gray to bluish gray, but often brownish black externally 
 from the oxidation of the manganese present. Streak 
 grayish white. Lustre subresinous. H.=5. G.=3°54-3°6. 
 
 Composition. (+i, ?R); O; P., in which R stands for Fe 
 and Mn. <A Bodenmais specimen afforded Phosphorus 
 pentoxide 44°19, iron protoxide 38°21, manganese protoxide 
 5°63, magnesia 2°39, lime 0°76, lithia 7°69, soda 0°74, pot- 
 ash 0:04, silica 0:-40=100°05. B.B. fuses very easily, color- 
 ing the flame a beautiful red, in streaks, with a pale bluish- — 
 green on the exterior of the flame. Soluble in hydrochloric 
 acid, 
 
 Obs. Found at Rabenstein in Bavaria; in Finland ; at 
 Norwich, Mass.; Grafton, N. H. 
 
 Lithiophilite. A salmon-colored manganese-lithium phosphate, al- 
 lied in composition to triphylite, but containing very little iron. 
 From Redding (near Branchville Depot), Conn. 
 
MANGANESE. 191 
 
 Triplite. 
 
 Trimetric. Usually massive, with cleavage in three di- 
 rections. Color blackish brown. Streak yellowish gray. 
 Lustre resinous ; nearly or quite opaque. H.=d-5°5. G.= 
 3°4-3'8. 
 
 Composition. (Mn,Fe),O,P,+RF,, affording about 30 
 per cent. of manganese protoxide, 8 of fluorine. Fuses 
 easily to a black magnetic globule. B.B. imparts a violet 
 color to the hot borax bead.  Dissolves in hydrochloric 
 acid. 
 
 Obs. From Limoges in France. Rather abundant at 
 Washington, Conn., and sparingly found at Sterling, Mass. 
 
 Heterosite, Alluaudite, Pseudotriplite, are regarded as results of 
 alteration, either of triphyline or of triplite. 
 
 Triploidite. A manganese-iron phosphate like triplite, but having 
 the fluorine replaced by the elements of water. From Redding, Conn. 
 
 Dickinsonite. An oil-green to olive-green manganese-iron-calcium 
 phosphate. From Redding, Conn. 
 
 Reddingite. A rose-pink hydrous manganese-iron phosphate. Mn, 
 O, P,+8.aq, isomorphous with scorodite and strengite. Redding, Ct. 
 
 Fairfieldite, hydrous manganese-calcium phosphate. Ibid. 
 
 Hureaulite. Rose-colored to brownish-orange hydrous manganese- 
 iron phosphate. From Hureaux, France. 
 
 Rhodochrosite.—Manganese Carbonate. 
 
 Rhombohedral. RA R= 166° 51’; like calcite in hav- 
 ing three easy cleavages, and in lustre. Color rose-red. 
 H.=8%5-4'5. Ge=3°4-3°7. 7 
 
 Composition. Mn O,C=Carbonic acid 386, manganese 
 protoxide 61°4=100. Part of the manganese often replaced 
 by calcium, magnesium or iron. 
 
 Obs. From Saxony, Transylvania, the Hartz, Ireland; 
 Mine Hill, New Jersey ; Redding, Conn.; Austin, Nevada ; 
 Placentia Bay, Newfoundland. 
 
 Rhodonite. Amanganese silicate. See p. 247. 
 
 General Remarks. Manganese is never used in the arts in the pure 
 state ; but as an oxide it is largely employed in bleaching. The im- 
 portance of the ore for this purpose depends on the oxygen it con- 
 tains, and the facility with which this gas is given up. As the ores 
 are often impure, it is important to ascertain their value in this re- 
 spect. This is most readily done by heating gently the pulverized ore 
 with hydrochloric acid, and ascertaining the amount of chlorine given 
 off. The chlorine may be made to pass into milk of lime, to form a 
 chloride, and the value of the chloride then tested according to the 
 usual modes. The amount of chlorine derived from a given quantity 
 
192 DESCRIPTIONS OF MINERALS. 
 
 of muriatic acid depends not only on the amount of oxygen in the ore, 
 but also on the presence or absence of baryta and such other earths as 
 may combine with this acid. The binoxide of manganese, when pure, 
 affords 18 parts by weight of chlorine, to 22 parts of the oxide ; or 234 
 cubic inches of gas from 22 grains of the oxide. The best ore should 
 give about three-fourths its weight of chlorine, or about 7,000 cubic 
 inches to the pound avoirdupois. 
 
 Iron ores containing some manganese are used for making sptegeleisen, 
 a hard highly crystallized pig-iron, containing a large amount of car- 
 bon and some manganese. A manganesian iron carbonate or siderite is 
 thus used, and also the franklinite of New Jersey. 
 
 Manganese is also employed to give a violet color to glass. The 
 sulphate and the chloride of manganese are used in calico printing. 
 The sulphate gives a chocolate or bronze color. 
 
 ALUMINUM. 
 
 The aluminum compounds among. minerals include only 
 one oxide—a sesquioxide Al O;,—hydrated oxides, fluorides, 
 and, among ternaries, sulphates, phosphates, and numerous 
 silicates. There are no sulphides or arsenides, and no car- 
 bonate, with a single imperfectly understood exception. 
 
 The silicates are described in the following section. Many 
 aluminum compounds may be distinguished by means of a 
 blowpipe experiment, as explained on page 87. 
 
 Corundum. 
 
 Rhombohedral. RA R or rAr=86° 4’. Cleavage some- 
 times perfect parallel with O, and sometimes par- 
 allel to the rhombohedral faces. Usual in six- 
 sided prisms, often with uneven surfaces, and 
 sometimes so irregular that the form is scarcely 
 traceable. Occursalso granular. Colors blue, 
 and grayish-blue most common ; also red, yel- 
 low, brown, and nearly black; often bright. 
 When polished on the surface O, a star of six 
 rays, corresponding with the six-sided form of 
 the prism, is sometimes seen within the crystal. » 
 Transparent to translucent. H.=9, or next below the 
 diamond. Exceedingly tough when compact. G.=3-9-4'10. 
 
 Composition. AlO,=Oxygen 46°8, aluminum 53°2=100; 
 pure alumina. B.B. remains unaltered both alone and with 
 soda. The fine powder moistened with cobalt nitrate and 
 ignited assumes a blue color. | 
 
 
 
COMPOUNDS OF ALUMINUM. 193 
 
 VARIETIES. The name sapphire is usually restricted, in 
 common language, to clear crystals of bright colors, used as 
 gems ; While dull, dingy-colored crystals and masses are 
 called corundum, and the granular variety of bluish-gray 
 and blackish colors containing much disseminated magne- 
 tite (whence its dark color) is called emery. 
 
 Siue is the true sapphire color. When of other bright 
 tints, it receives other names; as orvental ruby, when red ; 
 oriental topaz, when yellow ; oriental emerald, when green ; 
 oriental amethyst, when violet, and adamantine spar, when 
 hair-brown. Crystals with a radiate chatoyant interior are 
 often very beautiful, and are called asteria, or asteriated 
 sapphire. 
 
 Diff. Distinguished readily by its hardness, exceeding all 
 species except the diamond, and scratching quartz crystals 
 with great facility. 
 
 Obs. The sapphire is often found loose in the soil. Meta- 
 morphic rocks, especially gneissoid mica schist, and granu- 
 lar limestone, appear to be its usual matrix. It is met with 
 in several localities in the United States, but seldom suffi- 
 ciently fine for a gem. A blue variety occurs at Newton, 
 N. J., in crystals sometimes several inches long ; bluish and 
 pink, at Warwick, N. Y.; white, blue, and reddish crystals 
 at Amity, N. Y.; grayish, in large crystals, in Delaware 
 and Chester counties, Pennsylvania; pale blue crystals 
 have been found in bowlders at West Farms and Litchfield, 
 Conn. It occurs also in large quantities in North Carolina, 
 where crystals are numerous though rarely fit for jewelry, 
 and where one has been obtained weighing 312 pounds, and 
 having a reddish color outside and bluish-gray within ; also 
 in Cherokee County, Georgia ; in Los Angeles County, Cali- 
 fornia. Emery is mined at Chester, in Mass. 
 
 The principal foreign localities are as follows : blue, from 
 Ceylon ; the finest red from the Capelan Mountains in the 
 kingdom of Ava, and smaller crystals from Saxony, Bohemia 
 and Auvergne ; corundum, from the Carnatic, on the Mala- 
 bar coast, and elsewhere in the East Indies; adamantine 
 spar, from the Malabar coast ; emery, in large bowlders 
 from near Smyrna, and also at Naxos and several of the 
 Grecian islands. 
 
 The name sapphire is from the Greek word sapphevros, 
 the name of a blue gem. It is doubted whether it included 
 
 the sapphire of the present day. oh 
 
194 DESCRIPTIONS OF MINERALS. 
 
 Next to the diamond, the sapphire in some of its varieties 
 is the most costly of gems. The red sapphire is much more 
 highly esteemed than those of other colors. A crystal of 
 one, two or three carats is valued at the price of a diamond 
 of the same size. ‘They seldom exceed half an inch in their 
 dimensions. Two splendid red crystals, as long as the little 
 finger and about an inch in diameter, are said to be in the 
 possession of the king of Arracan. The largest oriental ruby 
 known was brought from China to Prince Gargarin, gov- 
 ernor of Siberia; it afterward came into the possession of 
 Prince Menzikoff, and constitutes now a jewel in the im- 
 perial crown of Russia. 
 
 Blue sapphires occur of much larger size. According to 
 Allan, Sir Abram Hume possessed a crystal which was three 
 inches long. One of 9°51 carats is stated to have been found 
 in Ava. 
 
 Corundum and emery are crushed to a powder of differ- 
 ent degrees of fineness, and make the abrading and polishing 
 material called in the shops emery. ‘The iron oxide of true 
 emery diminishes its hardness, and consequently its abrasive 
 power ; pulverized corundum is more valuable and efficient 
 in abrasion. 
 
 Diaspore. Hydrated aluminum of the formula Al0, H,—Water 14°9, 
 alumina 85'1—100. Usually found associated with corundum. Crys- 
 tals usually thin and flattened. Color whitish, grayish, pinkish, etc. 
 Very brittle. Translucent. H. 6-5-7. G. 3°5. From the Urals; 
 Schemnitz; Chester, Mass. ; Chester County, Pa.; North Carolina. 
 
 Gibbsite (Hydrargillite). Hydrated alumina ; Al O, He=water 34:5, 
 alumina 65°5—100. Occurs in hexagonal crystals ; more commonly in 
 stalactitic and mammillary forms, with smooth surface, looking like 
 chalcedony. Color white, grayish and greenish-white ; translucent, 
 sometimes transparent when in crystals. H.—2°5-3°5; G.=2°3-2°4. 
 Near Slatoust in the Ural ; in Asia Minor ; on corundum at Unionville, 
 Pa.; at Richmond, Mass. in stalactitic forms ; in Orange County, N. Y. 
 
 Hydrotalcite ( Volknerite, Houghite). A soft pearly mineral, contain- 
 ing alumina, magnesia, and water. Accompanies spinel, and some- 
 times a result of the alteration of spinel crystals. Occurs near Sla- 
 toust; at Snarum, Norway ; near Oxbow in Rossie, St, Lawrence 
 County, N. Y, (the variety Houghite). 
 
 Spinel. 
 
 Isometric. In octahedrons, more or less modified. Fig- 
 ure 4 represents a twin crystal. Occurs only in crystals ; 
 cleavage octahedral, but difficult. | 
 
 Color red, passing into blue, green, yellow, brown, and 
 
COMPOUNDS OF ALUMINUM. 195 
 
 black. The red shades often transparent and bright; the 
 dark shades usually opaque. Lustre vitreous. H.=8. 
 G,=3*5-4°1. 
 
 is 
 
 are 
 ie 
 
 N 
 
 
 
 Composition. MgAl O,=Mg0O+Al10,= Alumina 72, mag- 
 nesia 28=100. The aluminum is sometimes replaced in 
 part by iron, and the magnesium often in part by iron, cal- 
 cium, manganese and zinc. Infusible; insoluble in acids. 
 
 VARIETIES. ‘The following varieties of this species have 
 received distinct names: the scarlet or bright red crys- 
 tals, spinel ruby ; the rose-red, balas-ruby ; the orange-red, 
 rubicelle ; the violet, almandine-ruby ; the green, chloro- 
 spinel ; while the black varieties are called pleonaste. Pleo- 
 naste crystals contain sometimes 8 to 20 per cent. of oxide 
 of iron. Picotite is a variety containing 7 per cent. of 
 chromium oxide. 
 
 Diff. The form of the crystals and their hardness dis- 
 tinguish the species. Garnet is fusible. Magnetite is at- 
 tracted by the magnet. Zircon has a higher specific gravity 
 and is not so hard. The red crystals often resemble the 
 true ruby (red corundum), but the latter are never in octa- 
 hedrons. 
 
 Obs. Occurs in granular limestone; also in gneiss and 
 volcanic rocks. At numerous places in the adjoining coun- 
 ties of Sussex in New Jersey, and Orange county, of various 
 
196 DESCRIPTIONS OF MINERALS. 
 
 colors from red to brown and black ; especially at Frank- 
 lin, Newton and Sparta, in the former, and in Warwick, 
 Amity and Edenville, in the latter. The crystals are octa- 
 hedrons, and often grouped or disseminated singly in gran- 
 ular limestone. One crystal, found at Amity by Dr. Heron, 
 weighs 49 pounds. The limestone quarries of Bolton, Box- 
 borough, Chelmsford and Littleton, Mass., afford a few 
 crystals. 
 
 Crystals of spinel are occasionally soft, having under- 
 gone a change of composition approaching steatite in all 
 characters except form. Theyare true pseudomorphs. ‘They 
 are met with in Sussex and Orange counties. Other spinel 
 pseudomorphs consist of hydrotalcite (see preceding page). 
 
 Uses. Vhe fine colored spinels are much used as gems. 
 The red is the common ruby of jewelry, the oriental rubies 
 being sapphire. 
 
 Gahnite is a spinelin which zinc takes the place of part or all of the 
 magnesium; when all, itis called Automolite. Color dark green or green- 
 ish black. H.=7°5-8. G.=4-4°6. When fused with sufficient soda, 
 B.B. on coal a white coat of zinc oxide is deposited, which is yellow 
 when hot. B.B. infusible. At Franklin, N. J., and at the Canton 
 mine in Georgia. Occurs in granite at Uaddam with beryl, chryso- 
 beryl,garnet, etc. In Sweden, near Fahlun, in talcose slate. 
 
 Dysluite. A variety of gahnite containing oxide of manganese. 
 Color yellowish or grayish-brown. T.—75-8. G.=4:55. Composi- 
 tion, Alumina 30'5, zine oxide 16°8, iron sesquioxide 41‘9, manganese 
 protoxide 7°6, silica 8, water 0-4. From Sterling, N. J., with frank- 
 linite and troostite. , 
 
 Kreittonite is a zinc-iron gahnite. 
 
 Hercinite is aspinel affording on analysis alumina and iron protoxide, 
 with only 2°9 per cent. of magnesia. 
 
 , Chrysoberyl. 
 
 Trimetric. IA I=129° 38’. Also in compound crystals, 
 as in fig. 7% Crystals sometimes thick ; often tabular. 
 
 Color bright green, from a light shade to emerald-green ; 
 rarely raspberry or columbine-red by transmitted light. 
 Streak uncolored. Lustre vitreous. Transparent to trans- 
 lucent. *H-=8'5.. G.=3:5-3°8. 
 
 Composition. Be Al O, = Alumina 80:2, glucina 19°3=100. 
 A little iron is sometimes present. B.B. infusible and un- 
 altered. ; 
 
 ‘Alexandrite is an emerald-green variety from the Urals, 
 colored by chrome, bearing the same relation to ordinary 
 chrysoberyl as emerald to beryl. _ Fig. 7 is of this variety. _ 
 
COMPOUNDS OF ALUMINUM. 197 
 
 Diff. Near beryl, but distinct in not being regularly hex- 
 agonal in crystallization. : 
 
 Obs. Chrysoberyl occurs in the United States in granite 
 at Haddam, Conn., and Greenfield, near Saratoga, N. Y., 
 associated with beryl, garnet, etc.; in Norway, Maine. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 The name chrysoberyl is from the Greek chrysos, golden, 
 and beryllos, beryl. 
 
 The crystals are seldom sufficiently pellucid and clear 
 from flaws to be valued in jewelry ; but when of fine qual- 
 ity, it forms a beautiful gem, and is often opalescent. 
 
 Fluorides of Aluminum. 
 
 Cryolite. In snow-white masses, having rectangular cleavages, and 
 remarkable for melting easily in the flame of a candle, to which its 
 name (from the Greek krwos, ice) alludes. H.=25. G.=2°95. Itis 
 a sodium-aluminum fluoride. From Greenland. 
 
 Chiolite and Chodneffite are near cryolite in composition and charac- 
 ters. Arksutite, Gearksutite, Pachnolite, Thomsenolite are related fluor- 
 ine compounds which occur associated with the Greenland cryolite. 
 From Siberia. 
 
 Fluellite. From Cornwall, in minute white rhombic octahedrons. 
 Contains fluorine and aluminum. 
 
 Alunogen.—Hydrous Aluminum Sulphate. 
 
 In silky efflorescences, and crusts of a white color, having 
 a taste like common alum. H.=1'5-2. G.=1:6-1°8. 
 
 Composition. AlO.S,+18aq = Sulphur trioxide 36:0, 
 alumina 15:4, water 48°6=100. ‘ 
 
 Obs. A common efflorescence in solfataras of volcanic 
 regions, and also often occurring in shales of coal regions 
 and other rocks containing pyrite ; the oxidation of the 
 pyrite—an iron sulphide—affords sulphuric acid, which 
 acid combines with the alumina of the shale. 
 
198 DESCRIPTIONS OF MINERALS. 
 
 Alums. Frequently the sulphuric acid resulting from the oxidation 
 of asulphide, or in some other way, combines also with the iron, 
 magnesia or potash or soda of the shale or other rock, as well as the 
 alumina, and so makes other kinds of aluminum sulphate. 
 
 Combining thus with potash it produces common alum called Kali- 
 nite or potash alum, whose formula is K,Al, 0,, 8, + 18 aq; with am- 
 monia, it forms an ammonia-alum, named “schermigite ; with iron, 
 iron-alum, called Halotrichite ; with soda, a soda-alum, Mendozite ; 
 with magnesia a magnesia-alum, Pickeringite ; with manganese, a 
 manganese-alum, Apjonite and Bosjemanite. The formulas of these 
 alums are alike in atomic proportions, excepting in the amount of 
 water, which varies from 18 aq to 24 aq. 
 
 Shale containing alunogen or any of the alums is often called alum 
 shale. Such rocks, whether shales or of other kinds, are often quar- 
 ried and lixiviated for the alum they contain or will afford. The rock 
 is first slowly heated after piling it in heaps, in order to decompose 
 the remaining pyrites and transfer the sulphuric acid of any iron sul- 
 phate to the alumina and thus produce the largest amount possible of 
 aluminum sulphate. It is next lixiviated in stone cisterns. The lye 
 containing this sulphate is afterwards concentrated by evaporation, 
 and then the requisite proportion of potassium in the form of the sul- 
 phate or chloride is added to the hot solution. Oncooling, the alum 
 crystallizes out, and is afterwards washed and re-crystallized. The 
 mother liquor left after the precipitation is revaporated to obtain the 
 remaining alum held in solution, This process is carried on exten- 
 sively in Germany, France, at Whitby in Yorkshire, Hurlett and 
 Campsie, near Glasgow, in Scotland. Cape Sable in Maryland affords 
 large quantities of alum annually. The slates of coal beds are often 
 used to advantage in this manufacture, owing to the decomposing 
 pyrites present. At Whitby, 130 tons of calcined schist give one ton 
 of alum. In France, ammoniacal salts are used instead of potash, 
 and an ammonia alum is formed. 
 
 Alum is also manufactured from cryolite (see p. 197), which is ob- 
 tained from Greenland. 
 
 Alunite.—Alum Stone. 
 
 Rhombohedral, with perfect basal cleavage. Also mas- 
 sive. Color white, grayish, or reddish. Lustre of crystals 
 vitreous, or a little pearly on the basal plane. Transparent 
 to translucent. H.=4. G.=2:58-2°7. 
 
 Composition. Ky Al Oo S4+6 aq= Sulphuric trioxide 38°5, 
 alumina 37:1, potash 11°4, water 13-°0—100. B.B. decrepi- 
 tates and is infusible ; gives reaction for sulphur. 
 
 Diff. Distinguished by its infusibility, in connection with 
 its complete solubility in sulphuric acid without forming a 
 jelly. 
 
 Obs. Found in rocks of volcanic origin at Tolfa, near 
 Rome ; and also at Beregh and elsewhere in Hungary. 
 
 When it is calcined the sulphates become soluble, and the 
 
COMPOUNDS OF ALUMINUM. 199 
 
 alum is dissolved out. On evaporation the alum crystallizes 
 from the fluid in cubic crystals. This is called Roman alum, 
 and is highly valued by dyers, because, although the crystals 
 are colored red by iron oxide, no iron is chemically com- 
 bined with the salt as is usual in common alum. 
 
 Aluminite (Websterite). Another hydrous aluminum sulphate, in 
 compact reniform masses, and tasteless. . From New Haven, in Sussex ; 
 Epernay, in France ; and Halle, in Prussia, 
 
 Lewigite is a potassium-aluminum sulphate, containing half the 
 water of potash alum. 
 
 Amblygonite.—Lithium-Aluminum Phosphate. 
 
 Triclinic, with cleavages unequal in two directions, mak- 
 ing an angle with one another of 1044°. Lustre vitreous 
 to pearly and greasy. Color pale mountain-green, or sea- 
 green to white. *‘lranslucent to subtransparent. H.=6. 
 G.=3-3°'11. 
 
 Composition. A lithium-aluminum phosphate, A1O; P.+ 
 13 (Li, Na) F. B.B. fuses very easily with intumescence, 
 coloring the flame yellowish red to rich carmine-red, owing 
 to the lithia present, and traces of green owing to the phos- 
 phoric acid. Gives the reaction also for fluorine. 
 
 Obs. Occurs in Saxony and Norway. 
 
 Hebronite is a closely related mineral from Hebron and Mount Mica 
 in Maine, and from Redding in Connecticut. 
 
 Herderite is supposed to be an anhydrous calcium-aluminum phos. 
 phate with fluorine. 
 
 Durangite. An anhydrous arsenate of an orange-red color, contain- 
 ing aluminum, sodium, iron, and some manganese, with over 7 per 
 cent. of fluorine. From Durango, Mexico, where it occurs with cas- 
 siterite or tin ore. 
 
 Lazulite. 
 
 Monoclinic. In crystals and also massive, of an azure-blue 
 color, H.=5-6. G.=3°057. 
 
 Composition. RAl O, P,-+aq= Phosphorus pentoxide 46°8, 
 alumina 340, magnesia 13:2, water 6°0=100. B.B. in the 
 closed tube whitens and yields water ; with cobalt solution 
 the color is restored; in the forceps whitens, swells, cracks, 
 and falls to pieces without fusion, coloring the flame bluish- 
 
 reen. | | 
 Obs. From Salzburg, Styria; Wermland, Sweden; Crowder 
 Mount, Lincoln County, N.C. ; and on Graves Mountain, 
 Lincoln County, Georgia. 
 
200 DESCRIPTIONS OF MINERALS. 
 
 Variscite (Peganite, Callainite) is another hydrous aluminum phos- 
 phate ; it is of a light green color, of various shades, to deep emerald- 
 green. From Montgomery County, Arkansas, and from Colorado ; also 
 from Messbach, in Saxon Voigtland. ischerite is a related mineral. 
 
 Turquois. 
 
 In opaque reniform masses without cleavage; of a bluish- 
 green color, and somewhat waxy lustre. H.=6. G.=2°6 
 —2°8. 
 
 Composition. Phosphorus pentoxide 32°6, alumina 46°9, 
 water 20°5=100. B.B. infusible, but becomes brown and 
 colors the flame green ; soluble in hydrochloric acid ; moist- 
 ened with the acid it gives a momentary bluish green color 
 to the flame, owing to the copper that it contains. 
 
 Diff. Distinguished from bluish-green feldspar, which it 
 resembles, by its infusibility and the reactions for phos- 
 phorus. 
 
 Obs. Turquois is brought from a mountainous district in 
 Persia, not far from Nichabour; and, according to Agaphi, 
 occurs in veins that traverse the mountain in every direc- 
 tion. 
 
 The Callais of Pliny was probably turquois. Pliny, in 
 his description of it, mentions the fable that it was found 
 in Asia, projecting from the surface of inaccessible rocks, 
 whence it was obtained by means of slings. 
 
 Turquois receives a fine polish and is highly esteemed as 
 a gem. In Persia it is much admired, and the Persian 
 king is said to retain for himself all the large and more 
 finely tinted specimens. The occidental or bone turquois, 
 is fossil teeth or bones, colored with a little phosphate of 
 iron. Green malachite is sometimes substituted for turquois, 
 but it is of little hardness and has a different tint of color. 
 The stone is so well imitated by art as scarcely to be detected 
 except by chemical tests. The imitation is much softer 
 than true turquois. 
 
 ; Childrenite. A hydrous phosphate containing aluminum, iron, with 
 little manganese. Found in trimetric crystals in Devonshire and 
 Cornwall ; also at Hebron in Maine. 
 
 Losphorite. Has the crystalline form and nearly the angles of chil- 
 drenite, and contains the same constituents, but differs in being 
 essentially a hydrous phosphate of manganese with little iron. From 
 Redding, Connecticut. 
 
 Henwoodite is a hydrous aluminum phosphate from Cornwall, con- 
 taining also copper, 
 
COMPOUNDS OF CERIUM, YTTRIUM, LANTHANUM. 201 
 
 Wavellite. 
 
 Trimetric. Usually in small hemispheres a third or half 
 an inch across, attached to the i 
 
 surface of rocks, and having a 
 finely radiated structure within ; 
 when broken off they leave a stel- 
 late circle on the rock. Some-- 
 times in rhombic crystals. 
 
 Color white, green, or yellowish and brownish, with a 
 somewhat pearly or resinous lustre. Sometimes gray or 
 black. ‘l'ranslucent. H.=3-5-4. G.=2:°3. 
 
 Composition. Al,O.P,+12aq = Phosphorus pentoxide 
 35°16, alumina 38:10, water 2674=100. 1 to 2 per cent. 
 of fluorine is often present, replacing the oxygen. B.B. 
 whitens and swells, but does not fuse. Colors the flame 
 green, especially if previously moistened with sulphuric 
 acid, Moistened with cobalt nitrate, assumes a blue color 
 after ignition ; gives much water in the closed glass tube. 
 
 Niff. Distinguished from the zeolites, some of which it 
 resembles, by giving the reaction of phosphorus, and also 
 by dissolving in acids without gelatinizing. Cacoxene, to 
 which it is allied, becomes dark reddish-brown before the 
 blowpipe. and does not give the blue with cobalt nitrate. 
 
 Obs. Occurs at the slate quarries of York County, Pa., 
 and also at Washington Mine, Davidson County, N. C.; at 
 Magnet Cove, Ark. It was first discovered by Dr. Wavel, 
 in clay slate in Devonshire. Occurs also in Bohemia and 
 Bavaria. 
 
 Zepharovichite is near wavellite. 
 
 Mellite or Honey stone. In square octahedrons, looking like a honey- 
 yellow resin ; may be cut with a knife. It is an aluminum mellate. 
 Found in Thuringia, Bohemia, Moravia, etc. 
 
 Dawsomte. Hydrous aluminum-calcium carbonate, from a felsyte 
 dike near Montreal. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 CERIUM, YTTRIUM, ERBIUM, LANTHANUM, DIDYMIUM. 
 
 Known in nature in the condition of fluorides, tantalates, 
 columbates, phosphates, or carbonates, and also as constitu- 
 ents in several silicates. 
 
 Yttrocerite. 
 
 Massive, of a violet-blue color, somewhat resembling a 
 
902 DESCRIPTIONS OF MINERALS. 
 
 purple fluor- spar ; sometimes reddish-brown. Opaque. 
 Lustre glistening. H.=4-5. G.=34—3°9. 
 
 Composition. Fluorine 25-1, lime 4-6, cerium protox- 
 ido 18°2, and yttria 91. Infusible alone before the blow- 
 pipe. 
 
 Obs. From Finbo and Broddbo, near Fahlun, in Sweden, 
 with albite and topaz in quartz. Also from Mt. Mica, 
 Maine ; Massachusetts, probably in Worcester County; and 
 from Amity, Orange County, N.Y. 
 
 Fluocerite and Fluocerine are other fluorides containing cerium, from 
 Sweden. 
 
 Samarskite.” 
 
 Trimetric. IA 1=122° 46’. Usually massive, without 
 cleavage, with a velvet-black color and shining submetallic 
 lustre. Streak dark-reddish brown. Opaque. l.=9'5-6. 
 G.=5'6-5'8. 
 
 Composition. Analyses of the American afford columbic 
 and tantalic pentoxide, with sesquioxides of yttrium (12-15 
 per cent.), cerium, iron, and oxide of uranium. In the 
 closed tube decrepitates and glows. B.B. fuses on the 
 edges toa black glass. With salt of phosphorus in both 
 flames, an emerald-green bead. 
 
 Obs. Occurs at Miask, in the Ural; also in masses, 
 sometimes weighing many pounds, at the Mica mines of 
 Western North Carolina, along with columbite. 
 
 Nohlite is near samarskite, but contains 4°62 of water. 
 
 Fergusonite. A hydrous columbate of yttrium, erbium, cerium. 
 Color brownish black ; lustre dull, but_brilliantly vitreous on a Ssur- 
 face of fracture. B.B. infusible, but loses its color. From Sweden, 
 Cape Farewell, Greenland, and Rockport, Mass. 
 
 Kochelite is near fergusonite. 
 
 Vttro-tantalite. A tantalate and columbate of yttrium, erbium, and 
 iron. The different varieties are the black, the yellow, and brown or 
 dark-colored. They are infusible. From Ytterby, Sweden, and at 
 Broddbo and Finbo, near Fahlun. 
 
 Euzenite. A columbate and tantalate of yttrium, uranium, erbium, 
 and cerium. Massive. Color brownish black. Streak reddish brown. 
 B.B. infusible. From Norway; also from N. Carolina. 
 
 Sypylite. A columbate and tantalate of erbium and yttrium, re- 
 sembling fergusonite in aspect. From Amherst County, Va. 
 
 Pyrochlore, Microlite, Disanalyte, under CALCIUM, P. 214 
 
 ischynite. In crystals, black to brownish yellow ; lustre resinous 
 to submetallic ; streak gray to yellowish brown or black. H.=5-6. 
 G.—4:9-51. Acolumbate and titanate of cerium, thorium, and lan- 
 thanum. From Miask, in the Urals, in feldspar with mica and zircon. 
 
 Polymignite and Polycrase, Related to eschynite, 
 
COMPOUNDS OF CERIUM, YTTRIUM, LANTHANUM. 203 
 
 Rogersite. A hydrous columbate of yttria, in whitish crusts, on 
 samarskite. From N. Carolina 
 
 Monazite. 
 
 Monoclinic. In modified oblique rhombic prisms ; ZAL 
 —93° 10’. Perfect and brilliant basal cleavage. Observed 
 only in small imbedded crystals. 
 
 Golor brown, brownish red; subtransparent to nearly 
 opaque. Lustre vitreous inclining to resinous. Brittle. 
 fiez0se (.=-4°0-5°1. 
 
 Composition. A phosphate containing cerium, lantha- 
 num, yttrium, didymium and thorium, with also a little 
 tin, manganese, and lime. B.B. it colors the flame green 
 when moistened with sulphuric acid and heated. Difficultly 
 soluble in acids. 
 
 Diff. The brilliant easy transverse cleavage distinguishes 
 monazite from sphene. 
 
 Obs. Occurs near Slatoust, Russia. In the United 
 States it is found in small brown crystals, disseminated 
 through a mica slate at Norwich, Conn. ; also at Chester, 
 Conn., and Yorktown, Westchester County, N. Y. 
 
 
 
 Cryptolite. A cerium phosphate in minute prisms (apparently six- 
 sided), found with the apatite of Arendal, Norway. Color pale wine- 
 yellow. G.=4'6. 
 
 Churchite. A phosphate of cerium, didymium and calcium ; from 
 Cornwall. 
 
 Xenotime. An yttrium phosphate having a yellowish-brown color, 
 pale brown streak, opaque, and resinous in lustre. Crystals square 
 prisms, with perfect lateral cleavage. H.—4-5. G.=4°6. Infusible 
 alone before the blowpipe ; insoluble in acids. From Lindesnaes, 
 Norway ; Ytterby, Sweden ; gold washings of Clarkesville, Ga., and 
 McDowell County, N. C. 
 
 Parisite. Is a carbonate containing cerium, lanthanum, and didy- 
 mium, with fluorine. From New Granada. 
 
 Lanthanite. Occurs in thin minute tables or scales of whitish or 
 yellowish color, and is a hydrous lanthanum carbonate. From Bast- 
 nis, Sweden, and Saucon Valley in Lehigh County, Pa. 
 
 Tengerite. An yttrium carbonate. Found in thin coatings at Yt- 
 terby, Sweden. 
 
 Rhabdophane. A didymium and erbium phosphate; from Corn- 
 wall, with sphalerite (blende), which it resembles. 
 
 Rutherfordite. A blackish-brown vitreo-resinous mineral, From 
 the gold mines of Rutherford County, N.C. 
 
 Allanite, Gadolinite, Keilhauite, and Tscheff kinite, are silicates con< 
 taining either cerium or yttrium, 
 
204 DESCRIPTIONS OF MINERALS. 
 
 MAGNESIUM. 
 
 Magnesium occurs, in nature, as an oxide or hydrated 
 oxide, and in the condition of sulphate, borate, nitrate, 
 phosphate, carbonate and silicate. 
 
 The sulphates and nitrate of magnesia are soluble in. 
 water, and are distinguished by their bitter taste; the 
 other native magnesian salts are insoluble. The presence 
 of magnesia, when no metallic oxides are present, is indi- 
 cated by a blowpipe experiment, explained on page 87. 
 
 Periclasite.—Periclase. Magnesium Oxide. 
 
 Isometric. In small grayish to dark-green imbedded 
 crystals, with cubic cleavage. JH. nearly 6. G.=3°674, 
 
 Composition. Mg O (or the same as for magnesia alba of 
 the shops), with a little iron. B.B. infusible. Soluble in 
 acids without effervescence. 
 
 From Mount Somma, Vesuvius, Italy. 
 
 Brucite.—Magnesium Hydrate. 
 
 Rhombohedral. In foliated hexagonal prisms and plates; 
 structure thin foliated, and thin lamin easily separated 
 and translucent; flexible but not elastic. Also fibrous. 
 Lustre pearly. Color white, often grayish or greenish. 
 Ey 305 oetG ee 
 
 Composition. Mg Oy H,= Magnesia 69:0, water 31°0=100. 
 B.B. infusible, but becomes opaque and alkaline. Soluble 
 in hydrochloric acid without effervescence. 
 
 Diff. It resembles tale and gypsum, but is soluble in 
 acids ; it differs from heulandite and stilbite also by its in- 
 fusibility. 
 
 Obs. Occurs in serpentine at Hoboken, N. J.; in Rich- 
 mond County, N. Y.; in Dutchess County, N. Y., at 
 Brewster’s ; at Texas, in Pennsylvania; also at Swinaness, 
 in Unst, one of the Shetland Isles. 
 
 The fibrous variety has been called nemalite; it resembles 
 amianthus ; it occurs at Hoboken. 
 
 Hydromagnesite. A pearly crystalline, or earthy, white, hydrous 
 carbonate of magnesia, from Hoboken, N. J., Texas, Pa., and elsewhere. 
 
 Spinel contains oxygen and magnesium along with aluminum. See 
 page 195. Magnesium is also present in some magnetite, a variety of 
 which is called magnoferrite. 
 
COMPOUNDS OF MAGNESIUM. _ 205 
 
 Chlormagnesite. A magnesium chloride from Vesuvius. 
 Carnallite. Ahydrous magnesium-potassium chloride. 
 Tachydrite. A hydrous magnesium-calcium chloride. 
 
 Eipsomite.—Epsom Salt. Magnesium Sulphate. 
 
 Trimetric. JA [=90° 34’. Cleavage perfect parallel with 
 the shorter diagonal. Usually in fibrous crusts, or botry- 
 oidal masses, of a white color. Lustre vitreous to earthy. 
 Very soluble, and taste bitter and saline. 
 
 Composition. Mg 0,8+%aq=Sulphur trioxide 32°5, mag- 
 ‘nesia 16°3, water 51°2=100. Liquefies in its water of crys- 
 tallization when heated. Gives much water which has an 
 acid reaction, in the closed glass tube. B.B. on charcoal 
 fuses, but finally gives an infusible mass that turns pink 
 when moistened with cobalt nitrate and ignited. 
 
 Diff. The fine spicula-like crystalline grains of Epsom 
 salt, as it appears in the shops, distinguish it from Glauber 
 salt, which occurs usually in thick crystals. 
 
 Obs. The floors of the limestone caves of the West often 
 contain Epsom salt in minute crystals mingled with the 
 earth. In the Mammoth Cave, Ky., it adheres to the roof 
 in loose masses like snowballs. It occurs as an _efflores- 
 cence in the galleries of mines and elsewhere. The fine 
 efflorescences suggested the old name hazr-salt. 
 
 At Epsom, in Surrey, England, it occurs dissolved in min- 
 eral springs, and from this place the salt derived the name 
 it bears. It occurs at Sedlitz, Aragon, and other places in 
 Europe ; also in the Cordilleras of Chili; and in a grotto in 
 Southern Africa, where it forms a layer an inch and a half 
 thick. 
 
 Its medical uses are well known. It is obtained for the 
 arts from the bittern of sea-salt works, and quite largely 
 from magnesian calcium carbonate,, by decomposing it with 
 sulphuric acid. The sulphuric acid takes the lime and 
 magnesia, expelling the carbonic acid ; and the sulphate of 
 magnesium remaining in solution is poured off from the cal- 
 cium sulphate, which is insoluble. Itis then crystallized by 
 evaporation. 
 
 Polyhalite. A brick-red saline mineral, with a weak bitter taste, 
 occurring in masses which have a somewhat fibrous appearance. A 
 hydrous calcium. magnesium sulphate. 
 
 Kieserite. A hydrous magnesium sulphate ; from Stassfurt. 
 
 Picromeride. A hydrous potassium - magnesium sulphate ; from 
 Stassfurt. 
 
206 DESCRIPTIONS OF MINERALS. 
 
 Bledite. A hydrous sodium-magnesium sulphate; from the salt 
 mines of Ischl, and near Mendoza. 
 
 Leweite. A hydrous sodium-magesium sulphate ; from Ischl. Con- 
 tains more sulphur trioxide than Bleedite. 
 
 Boracite.—Magnesium Borate. 
 
 Isometric. Cleavage octahedral; but only in traces. 
 
 1. Usual in cubes with only the 2, 
 alternate angles replaced; or 
 having all replaced, but four pez 
 of them different from the 
 other four. The crystals ‘are 
 translucent and seldom more \\ A 
 than a quarter of an inch ~ 
 through. Also massive. Color white or grayish ; sometimes 
 yellowish or greenish. Lustre vitreous. H.=7 when in 
 crystals, but softer when massive. G.=2:97. Becomes 
 electric when heated, the opposite angles of the cube be- 
 coming of opposite poles. 
 
 Composition. Mg, O,,Bs+4Mg Cl,=Boron trioxide 62:0, 
 magnesia 31:0, chlorine 7°0=100. B.B. fuses easily with in- 
 tumescence coloring the flame green. The fused globule 
 becomes crystalline on cooling. Dissolves in hydrochloric 
 acid, and moistened with cobalt nitrate turns pink on igni- 
 tion. 
 
 Diff. Distinguished readily by its form, high hardness, 
 and pyro-electric properties. 
 
 Obs. Boracite is found only with gypsum and common 
 salt. It occurs near Luneberg in Lower Saxony, and near 
 Kiel in the adjoining duchy of Holstein, also at Stassfurth, 
 Prussia. 
 
 Rhodizite, Resembles boracite in its crystals, but tinges the blow- 
 pipe flame deep red. It is supposed to be a lime-boracite. Occurs 
 with the red tourmaline of Siberia. Zudwigite. A magnesium-iron 
 borate ; fibrous and dark green to black. 
 
 Seaibelyite. A hydreus magnesium borate, from Southeastern 
 Hungary. 
 
 Warwickite. In rhombic prisms of 93° to 94°, hair-brown to black 
 with sometimes a copper-red tinge. A magnesium-titanium borate ; 
 from granular limestone of Edenville, N. Y. 
 
 Sussexite. A hydrous magnesium-manganese borate. Fibrous and 
 pearly. G=8:42. from Mine Hill, Franklin Furnace, Sussex Co., N. J. 
 
 Nitromagnesite. Occurs in white deliquescent efflorescences, having 
 a bitter taste, associated with calcium nitrate, in limestone caverns. It 
 is used, like its associate, in the manufacture of saltpetre. 
 
 Wagnerite. A magnesium fluo-phosphate, occurring in yellowish or 
 
 
 
COMPOUNDS OF CALCIUM. 207 
 
 grayish oblique rhombic prisms. Insoluble. We =5-5:5.. 6.071, 
 From Salzburg, Austria. jeru/fine is near wagnerite. 
 Hernisite and Resslerite are hydrous calcium arsenates. 
 Liineburgite. A magnesium boro-phosphate, from Liineburg. 
 
 Magnesite.—Magnesium Carbonate. 
 
 Rhombohedral. R: R=107° 29’. Cleavage rhombohedral, 
 perfect. Often massive, either granular, or compact and 
 porcelain-like, in tuberose forms ; also fibrous. 
 
 Color white, yellowish or grayish-white, or brown. Lus- 
 tre vitreous; fibrous varieties often silky. ‘Transparent to 
 opaque. H.=3—4:5. G.=3. 
 
 Composition. MgO,C=Carbon_ dioxide 52°4, magnesia 
 4%-6=100. Infusible before the blowpipe. After ignition 
 has an alkaline reaction. Nearly insoluble in cold dilute 
 hydrochloric acid, but dissolves with effervescence in hot. 
 
 Diff. Resembles some varieties of calcite and dolomite ; 
 but from a concentrated solution no calcium sulphate is 
 precipitated on adding sulphuric acid. The fibrous variety 
 is distinguished from other fibrous minerals by its eflerves- 
 cence in hot acid, which shows it to be a carbonate. 
 
 Obs. Magnesite is usually associated with magnesian 
 rocks, especially serpentine. At Hoboken, N. J., it occurs 
 in this rock in fibrous seams ; similarly at Lynnfield, Mass.; 
 and in Canada, at Bolton, imperfectly fibrous, traversing 
 white limestone. 
 
 When abundant it is a convenient material for the manu- 
 facture of magnesium sulphate or Epsom salt, to make 
 which, requires simply treatment with sulphuric acid. 
 
 Hydromagnesite. A hydrous magnesium carbonate. Ocenrs with 
 serpentine, at Hoboken, but more abundantly in Lancaster Co., Penn. 
 
 Dolomite. A magnesium and calcium carbonate. See page 219. 
 
 CALCIUM. 
 
 Calcium exists in nature in the state of fluorite, and this 
 is its only binary compound. © It occurs in ternaries in the 
 state of sulphate, borate, columbate, phosphate, arsenate, 
 carbonate, titanate and silicate. The carbonate (calcite and 
 limestone) is one of the three most abundant of minerals. 
 The fluoride and sulphate, and some silicates, are also of 
 very common occurrence. 
 
208 DESCRIPTIONS OF MINERALS. 
 
 With the exception of the calcium nitrate, none of the 
 native salts of lime are soluble in water except in small 
 proportions. They give no odor, and no metallic reaction 
 before the blowpipe; but they tinge the flame red, and 
 many of them give up a part of their acid constituent, and 
 become caustic and react alkaline. The specific gravity is 
 below 3°2, and hardness not above 5. 
 
 Fluorite.—Fluor Spar. Calcium Fluoride. \ 
 
 Isometric. Cleavage octahedral, perfect. Commonly in 
 crystals ; rarely fibrous; often compact, coarse or fine gran- 
 ular. Figures 1 to 4 represent common forms. 
 
 
 
 Colors usually bright; white, or some shade of light 
 ereen, purple, or clear yellow are most common ; rarely 
 rose-red and sky-blue; colors of massive varieties often 
 banded. Transparent, translucent or subtranslucent. H=4. 
 G.=3-3°25. Brittle. 
 
 Composition. Ca F,=Fluorine 48°7, calcium 51°3=100. 
 Phosphoresces when gently heated in the dark, affording 
 light of different colors; in some varieties emerald-green ; 
 in others, purple, blue, rose-red, pink, or orange. B.B 
 decrepitates, and ultimately fuses to an enamel, which pos- 
 sesses an alkaline reaction ; pulverized and moistened with 
 sulphuric acid, hydrofluoric acid gas is given off which cor- 
 rodes glass. The name Chlorophane has been given to the 
 variety that affords a bright green phophorescence. 
 
 Diff. In its bright colors, fluorite resembles some of the 
 gems, but its softness and its easy octahedral cleavage when 
 crystallized at once distinguish it. Its strong phosphores- 
 cence is a striking characteristic; and also its affording 
 
COMPOUNDS OF CALCIUM. — 209 
 
 easily, with sulphuric acid and heat, a gas that corrodes 
 lass. 
 
 . Obs. Fluorite occurs in gneiss, mica schist, clay slate, 
 
 limestone, and sparingly in beds of coal either in veins 
 
 or occupying cavities, or as imbedded masses. It is the 
 
 gangue in some lead mines. 
 
 Cubic crystals of a greenish color, over a foot each way, 
 have been obtained at Muscolonge Lake, St. Lawrence 
 County, N. Y.; near Shawneetown on the Ohio, a beautiful 
 purple fluor in grouped cubes of large size is obtained from 
 limestone and the soil of the region ; at Westmoreland, N. 
 H., at the Notch in the White Mountains, Blue Hill Bay, 
 Maine, Putney, Vt., and Lockport, N. Y., are other locali- 
 ties. The chlorophane variety is found with topaz at Trum- 
 bull, Conn. 
 
 In Derbyshire, England, fluor spar is abundant, and hence 
 it has received the name of Derbyshire spar. It 1s a com- 
 mon mineral in the mining districts of Saxony. 
 
 Calcium fluoride also exists in the enamel of teeth, in 
 bones and some other parts of animals ; also in certain parts 
 of many plants; and by vegetable or animal decomposition 
 it is afforded to the soil, to rocks, and also to coal beds in 
 which it has been detected. 
 
 Massive fluor receives a high polish, and is worked into 
 vases, candlesticks and various ornaments, in Derbyshire, 
 England. Some of the varieties from this locality, consist- 
 ing of rich purple shades banded with yellowish white, are 
 very beautiful. The mineral is difficult to work because 
 brittle. Fluor spar is also used for obtaining hydrofluoric 
 acid, which is employed in etching. ‘To etch glass, a pic- 
 ture, or whatever design it is desired to etch, is traced in 
 the thin coating of wax with which the glass is first covered; 
 a very small quantity of the liquid hydrofluoric acid is then 
 washed over it ; on removing the wax, in a few minutes, the 
 picture is found to be engraved on the glass. The same 
 process is used for etching seals, and any siliceous stone 
 will be attacked with equal facility. This application of 
 fluor spar depends upon the strong affinity between fluorine 
 and silicon. Fluor spar is also used as a flux to aid in re- 
 ducing copper and other ores, and hence the name flwor. 
 
 14 
 
910 DESCRIPTIONS OF MINERALS. 
 
 Gypsum.—Hydrous Calcium Sulphate. 
 
 Monoclinic. JAI=143°42'; 21A27+111° 42", Figure 
 6 represents a common twin (or arrow-head) crystal. Cleav- 
 age parallel to 7-2 very easy, affording 
 , thin pearly lamin ; parallel to O, w- 
 | perfect, giving a vitreous surface; par- 
 ! allel to J, fibrous. Occurs also in lam- ule 
 //) inated masses, often of large size; in Jie 
 4) fibrous masses, with a satin lustre; in 
 
 Y stellated or radiating forms consisting of Wy 
 narrow lamin ; also granular and com- Va 
 pact. 
 
 When pure and crystallized it is as clear and pellucid as 
 class, and hasapearly lustre. Other varieties are gray, yel- 
 low, reddish, brownish, and even black, and opaque. H.= 
 1 5-2, or so soft as to be scratched by the finger-nail. G.=2°33. 
 The plates bend in one direction and are brittle in another. 
 
 Composition. Ca O,S +2 aq= Sulphur trioxide 46°5, lime 
 32-6, water 20°9=100. B.B. becomes instantly white and 
 opaque and exfolates, and then fuses to a globule, which 
 when placed upon moistened turmeric paper shows an alka- 
 line reaction. In a closed tube much water is given off. 
 Dissolves quietly in hydrochloric acid, and the solution gives 
 a heavy precipitate with barium chloride. 
 
 The principal varieties are as follows : 
 
 Selenite, including the transparent crystallized gypsum, 
 so called in allusion to its color and lustre from selene, the 
 Greek word for moon. 
 
 Radiated and Plumose gypsum, having a radiated struc- 
 ture. 
 
 Fibrous gypsum or satin spar, white and delicately fibrous. 
 
 Snowy gypsum and Alabaster, including the white or light- 
 colored compact gypsum having a very fine grain. 
 
 Diff. The foliated gypsum resembles some varieties of 
 heulandite, stilbite, talc, and mica ; and the fibrous looks 
 like fibrous carbonate of lime, asbestus and some of the 
 fibrous zeolites; but gypsum in all its varieties is readily 
 distinguished by its softness ; its becoming an opaque white 
 powder immediately and without fusion before the blow- 
 pipe, and by not edervescing or gelatinizing with acids. 
 
 Obs. Gypsum forms extensive beds in certain limestones 
 and clay beds, and also occurs in volcanic regions. New 
 York, near Lockport, affords beautiful selenite and snowy 
 
 
 
COMPOUNDS OF CALCIUM. OTT 
 ; ’ 
 
 gypsum in limestone. At Camillus and Manlius, N. Y., and 
 in Davidson County, Tenn., are other localities. Fine crys- 
 tals of the form represented in figure 5 come from Poland 
 and Canfield, Ohio, and large groups of crystals from St. 
 Mary’s in Maryland. ‘Troy, N. Y., also affords crystals in 
 clay. In Mammoth Cave, Kentucky, alabaster occurs in 
 imitation of flowers, leaves, shrubbery, and vines. Alabas- 
 ter is obtained at Castelino in Italy, 35 miles from Leghorn. 
 Massive gypsum occurs abundantly in New York, from 
 Syracuse westward to the western extremity of Genesee 
 County, accompanying the rocks which afford the brine 
 springs; also in New Brunswick, especially at Hillsboro’, 
 where part is excellent alabaster; in Hants, Colchester, and 
 other districts in Nova Scotia; also in Ohio, Illinois, Vir- 
 ginia, Tennessce, Arkansas,and Nova Scotia; and in con- 
 nection with the Triassic beds of the Rocky Mountain 
 region; also abundant in Nevada and California. It is 
 abundant also in Europe. 
 
 Gypsum, when calcined, loses its water, becomes white, 
 is easily ground to a powder. ‘This powder, when mixed 
 with a little water, takes up water again and becomes hard 
 andcompact. This gypsum is plaster of Paris, and is used 
 for taking casts, making models, and for giving a hard finish 
 to walls. Alabaster is cut into vases and various ornaments, 
 statues, etc. It owes its beauty for this purpose to its snowy 
 whiteness, translucency, and fine texture. Moreover, owing 
 to its softness, it can be cut or carved with common cutting 
 instruments. Gypsum is ground up and used for improving 
 soils. 
 
 Anhydrite.—Anhydrous Calcium Sulphate. 
 
 Trimetric. In rectangular and rhombic prisms, cleaving: 
 _ easily in three directions, and readily breaking into square 
 Dine 1 AU 100° 80°: 1¢A17=85" and 1 
 95°. Occurs also fibrous and lamellar, often : 
 contorted ; also coarse and fine granular, 
 and compact. 
 
 Color white, or tinged with gray, red, or 2. 
 
 blue. Lustre more or less pearly. ‘T'rans- 
 parent to subtranslucent. H.=3-3°5. G. peer 
 Z 
 
 = 2'9-3. 
 Composition. CaOgS=Sulphur trioxide 
 
 3. 
 58°8, lime 41°2=100. It is an anhydrous S| 
 calcium sulphate, 3B.B. and with acids, aN 
 
212 DESCRIPTIONS OF MINERALS. 
 
 sts reactions are like those of gypsum, except that in the 
 closed tube it gives no water. 
 
 A scaly massive variety containing a little silica has been 
 named Vulpinite; contorted concretionary kinds are some- 
 times called Tripestone. Anhydrite is called by miners hard- 
 plaster, because harder than gypsum. 
 
 Diff. Its square forms of crystallization and cleavage are 
 good distinguishing characters. Its three easy cleavages, at 
 right angles with one another, look as if the erystalliza- 
 tion were cubic; but there is some difference in the ease 
 with which they may be obtained. 
 
 Obs. A fine blue crystallized anhydrite occurs with gyp- 
 sum and calcareous spar in a black limestone at Lockport, 
 and near Windsor in Nova Scotia, and Hillsboro’ in New 
 Brunswick. Foreign localities are at the salt mines of Bex 
 in Switzerland, Hall in the Tyrol, Ischl in Upper Austria, 
 Wieliczka in Poland, and elsewhere. 
 
 The vulpinite variety is sometimes cut and polished for 
 ornamental purposes. 
 
 Bechilite. A hydrous calcium borate occurring as an incrustation at 
 the Tuscan lagoons, Italy. A ‘‘ hydrous borate of lime” reported by 
 Hayes from Iquique, Peru, has been called Hayesine ; but its com- 
 position has been questioned, it being referred to Ulexite. Hovvlite. 
 A hydrous calcium borate, containing silica ; Windsor, Nova Scotia. 
 Called also Silicoborocalcite. 
 
 Ulexite or Boronatrocalcite. A hydrous calcium-sodium borate, in 
 aggregations of fibres, from the dry plains of Iquique, Southern Peru; 
 Nova Scotia, at Windsor, Brookville, and Newport; and Nevada, in 
 Siac. mining district, and at Thiel Salt Marsh, in Esmeralda 
 
 sOUNTY. 
 
 pear Re Another hydrous calcium-sodium borate ; Windsor, 
 Nova Scotia. Priceite is a calcium borate of white color and chalky 
 aspect, from Curry County, Oregon. 
 
 Hydroboracite. A hydrous calcium-magnesium borate, resembling 
 
 sum in aspect. 
 
 Scheelite. Calcium tungstate, of pale yellowish-white color; H.= 
 4-5-5. G.—5'9-6:1. From Monroe, Conn. ; North Carolina ; Mammoth 
 mining district, Nevada ; Charity Mine, Idaho ; Golden Queen Mine, 
 Lake Co., Colorado; Seattle, Washington ‘Territory ; at Caldbeck 
 Fell, near Keswick, England ; in Bohemia, Hartz, Saxony, Hungary, 
 
 Sweden, Vosges. Ouproscheelite has part of the calcium replaced by 
 
 copper; from La Paz, Lower California. 
 
 Apatite—Calcium Phosphate. 
 
 Hexagonal. In hexagonal prisms. The annexed figure 
 represents a common form. Cleavage imperfect. Usually 
 occurs im crystals; but occasionally massive ; sometimes 
 
COMPOUNDS OF CALCIUM. 213 
 
 mammillary with a compact fibrous structure. 
 Small crystals are occasionally transparent 
 and colorless, but the usual color is green, 
 often yellowish green, bluish green, and gray- 
 ish green; sometimes yellow, blue, reddish 
 or brownish. Coarse crystals nearly opaque. 
 
 Lustre vitreous to subresinous. H.=5. G 
 —3-3:25. Brittle. Some varieties phospho- 
 resce when heated, and some become electric 
 by friction. 
 
 Composition. Ca,O3 P.+4% (Cl, F,) = if without fluorine 
 Phosphorus pentoxide 40°92, lime 53°80, chlorine 6°82=100. 
 When chlorine is present in place of fluorine it is called 
 chlor-apatite, and when the reverse, flwor-apatite. B.B. in- 
 fusible except on the edges. Dissolves slowly in nitric acid 
 without effervescence. Its constituents are contained in 
 the bones and ligaments of animals, and the mineral has 
 probably been derived in many cases from animal fossils.* 
 
 Massive apatite is often called Phosphorite ; and the pale 
 yellowish-green crystals, Asparagus stone. Osteolite is a 
 white earthy apatite. Hupyrchroite is a fibrous mammil- 
 lary variety from Crown Point, Essex County, N. Y. 
 
 Fossil excrements, called coprolites, occur in stratified 
 rocks, and sometimes constitute extended beds ; and they 
 consist chiefly of calcium phosphate. Guano contains more 
 or less calcium phosphate along with hydrous phosphates 
 and some impurities. 
 
 Diff. Distinguished from -beryl by its inferior hardness, 
 it being easily scratched with a knife ; from calcite by dis- 
 solving in acids without effervescence ; from pyromorphite 
 by its difficult fusibility, and giving no metallic reaction 
 before the blowpipe. Phosphoric acid may be detected by 
 moistening it with sulphuric acid and igniting it B.B., 
 when it imparts a dirty green color to the flame. 
 
 Obs. Apatite occurs in gneiss, mica schist, hornblende 
 schist, granular limestone. In microscopic crystals it is 
 sparingly present in almost all crystalline rocks, the ig- 
 neous as well as metamorphic. The best crystals in the 
 United States occur in granular limestone ; the crystals 
 from the limestone of St. Lawrence County, N. Y., are 
 
 
 
 
 
 * Bones contain 25 per cent. of calcium phosphate, with some fluoride of calcium, 3 
 to12 per cent. of calcium carbonate, some magnesium phosphate and sodium chloride, 
 besides 83 per cent. of animal matter. 
 
214 DESCRIPTIONS OF MINERALS. 
 s 
 
 among the largest yet discovered in any part of the world ; 
 one from Robinson’s farm measured a foot in length and 
 weighed 18 pounds; but they are nearly opaque and the 
 edges are usually rounded. They occur with scapolite, 
 sphene, etc. Edenville and Amity, Orange County, N. Y., 
 afford fine crystals from half an inch to twelve inches 
 long. At Westmoreland, N. H., fine crystals are obtained 
 in a vein of feldspar and quartz; also at Blue Hill Bay 
 in Maine. Bolton, Chesterfield, Chester, Mass., are other 
 localities. .A beautiful blue variety is obtained at Dixon’s 
 quarry, Wilmington, Delaware. Abundant in Burgess, 
 Elmsley, Grand Calumet Id. Hull, Buckingham, Port- 
 land, etc., in Canada. 
 
 The name apatite, from the Greek apatao, to deceive, was 
 given in allusion to the mistake of early mineralogists re- 
 specting the nature of some of its varieties. 
 
 Apatite, when abundant, is used like guano as a fertilizer, 
 on account of its phosphoric acid. To make it capable of 
 being taken up by plants it is treated first with a small por- 
 tion of sulphuric acid, which renders the phosphoric acid 
 soluble. When guano has been accumulated by birds, or 
 other animals, over coral rock, a calcium carbonate (as on 
 some coral islands), the waters in filtrating through it have 
 often carried down the soluble phosphoric acid or phosphates 
 into the underlying beds and turned them into calcium 
 phosphate. 
 
 Brushite and Metabrushite. Hydrous calcium phosphates, found in 
 guano. 
 
 Pyrophosphorite. A white earthy phosphate from a guano deposit, 
 a the West Indies. Analysis gave it the composition of a pyrophos- 
 phate. 
 
 Pharmacolite and Haidingerite are hydroas calcium arsenates. 
 
 Nitrocalcite. WHydrous calcium nitrate. From caverns. 
 
 Pyrochilore. Occurs in small brown and brownish-yellow isometric 
 octahedrons. A calcium-cerium columbate. G.—4°3-4:5. From Nor- 
 way, Siberia. 
 
 Microlite. In crystals similar in form to those of pyrochlore, but 
 in composition a calcium tantalate. G.=5°5-6. From Chesterfield, 
 Mass., and Redding, Conn. Hatchettolite is a lime-uranium colum- 
 bate, from North Carolina. 
 
 Disanalyte. In cubes in granular limestone, a columbate and titan- 
 ate of calcium, cerium and iron. From the Kaiserstuhl. 
 
 Romeite and Atopite are calcium antimonates, the latter containing 
 also iron and soda. 
 
COMPOUNDS OF CALCIUM. 215 
 
 Calcite.—Calc Spar. Calcium Carbonate. 
 
 Rhombohedral. RAR (fig. 1)=105° 5’. Cleavage easy, 
 parallel with the faces of the fundamental rhombohedron. 
 
 
 
 Calcite with the form in fig. 7 is often called dog-tooth 
 spar. Occurs fibrous with a silky lustre ; sometimes lamel- 
 lar ; often coarse or fine granular, and compact. 
 
 The purest crystals are transparent with a vitreous lustre ; 
 the impure massive varieties are often opaque, and without 
 lustre, and even earthy. ‘The colors of the crystals are 
 either white or some light grayish, reddish or yellowish 
 tint, rarely deep red; occasionally topaz-yellow, rose or 
 violet. ‘The massive varieties are of various shades from 
 white to black, generally dull unless polished. H.=3. 
 G.=2°5-2°8. 
 
 Composition. Ca O,C=Carbon dioxide 44, lime 56=100. 
 Sometimes impure from mixture with iron, silica, clay, 
 bitumen, and other substances. B.B. infusible; colors the 
 flame reddish, gives up its carbon dioxide, is thereby made 
 caustic, in which state it gives an alkaline reaction. Effer- 
 vesces in dilute cold hydrochloric acid. Many varieties 
 phosphoresce when heated. 
 
 The following are the principal varieties. 
 
 Iceland spar. ‘Transparent crystalline calcite, first 
 brought from Iceland. Shows well double refraction. 
 
 Satin spar. A finely fibrous variety with a satin lustre. 
 Receives a handsome polish. Occurs usually in veins tra- 
 versing rocks of different kinds. 
 
 Chalk. White and earthy, without lustre, and so soft as 
 
916 DESCRIPTIONS OF MINERALS. 
 
 to leave a trace on a board. Forms mountain beds. Most 
 chalk was made chiefly out of the shells of Rhizopods. 
 
 Rock milk. White and earthy like chalk, but still softer, 
 and very fragile. It is deposited from waters containing 
 lime in solution. Rock meal is a powdery variety. 
 
 Calcareous tufa. Formed by deposition from waters like 
 rock milk, but more cellular or porous and not so soft. 
 
 Stalactite, Stalagmite. The name stalactite 1s explained 
 on page 60. The deposits of the same origin that cover 
 the floors of caverns are called stalagmite. They generally 
 consist of differently colored layers, and appear banded or 
 striped when broken. ‘lhe so-called ‘‘ Gibraltar rock” is 
 stalagmite from a cavern in the rock of Gibraltar. 
 
 Limestone is « general name for all the massive varieties 
 occurring in extensive beds. | 
 
 Oélite, Pisolite. Odlite is a compact limestone, consist- 
 ing of small round concretionary grains, looking like the 
 spawn of a fish; the name is derived from the Greek on, 
 an egg. Pisolite, a name derived from piswm, the Latin for 
 pea, differs from odlite in being: coarser ; the spherules 
 often have a concentric structure, and thus show their con- 
 cretionary origin. 
 
 Argentine. A white shining limestone consisting of la- 
 mine a little waving, and containing some silica. 
 
 Fontainebleau limestone. This name is applied to crys- 
 tals of the form shown in figure 3, containing a large pro- 
 portion of sand, and occurring in groups. They were for- 
 merly obtained at Fontainebleau, France, but the locality 
 is exhausted. 
 
 Granular limestone. A limestone consisting of crystal- 
 line grains, and hence often called crystalline limestone. 
 The coarser varieties when polished constitute the common 
 white and clouded marbles, and are the material of which 
 “marble” buildings are made. The finer are used for 
 statuary, and are called statuary marble. The best is as 
 clear and fine-grained as loaf sugar, which it much re- 
 ‘ sembles. 
 
 Compact limestone. The limestones breaking with a 
 smooth surface, without a distinctly granular texture, and . 
 dull in lustre unless polished. The rock is very variously 
 colored. The colors are sometimes arranged in blotches, or 
 veins. Kinds that are handsome when polished are used 
 as marbles. A black color is common, and is usually due to 
 
COMPOUNDS OF CALCIUM, 217 
 
 carbonaceous material of organic origin, and is proved by 
 the limestones becoming white when burnt. 
 
 Stinkstone, Anthraconite, A limestone which gives out 
 a fetid odor when struck. This odor is caused by certain. 
 bituminous materials present in the rock. 
 
 Lithographic stone. A very compact fine-grained lime- 
 stone of a gray or grayish-yellow color. 
 
 Hydraulic limestone. An impure limestone. It contains 
 silica and alumina in such a condition that, when burned, it 
 will make a cement that hardens under water. 
 
 Diff. Distinguished by being scratched easily with a knife, 
 in connection with strongly effervescing in dilute acid, 
 and its complete infusibility. Calcite is not.so hard as 
 aragonite, and possesses a very distinct cleavage, which 
 aragonite does not. 
 
 Obs. Crystallized cale spar occurs in magnificent forms 
 in the vicinity of Rossie, New York. One crystal from 
 there, now in the Peabody Museum at New Haven, weighs 
 165 pounds. Some rose and purple varieties from this 
 region are very beautiful. Large geodes of the dog-tooth 
 spar variety occur in limestone at Lockport, along with 
 gypsum and pearl spar. Leyden and Lowville, N. Y., are 
 other localities. Bergen Hill, N. J., affords beautiful 
 wine-yellow crystals in amygdaloidal cavities; also the 
 Lake Superior copper mines. Argentine occurs near 
 Williamsburg and Southampton, Mass. Rock milk covers 
 the sides of a cave at Watertown, N. Y., and is, now 
 forming Stalactites of great beauty occur in Weir’s and 
 other caves in Virginia and in the Western States ; also in 
 Ball’s Cave at Scoharie, N. Y. Chalk occurs in England 
 and Europe, and in Western Kansas in the United States. 
 Granular limestones are common in the Eastern and At- 
 lantic States, and compact limestones in the Middle and 
 Western States, and some beds of the former afford excellent 
 marble for building and some of good quality for stat- 
 wary. 
 
 Bay of the varieties of this mineral when burnt form 
 quicklime, heat driving off the carbonic acid and leaving 
 the lime in a caustic state. In this state it is used for mak- 
 ing mortar by mixing with water and sand; a calcium 
 hydrate results which becomes slowly carbonated through 
 carbonic acid in the atmosphere. See further the chapter 
 on Rocks, for the uses of limestone. 
 
218 DESCRIPTIONS OF MINERALS. 
 
 Aragonite. 
 
 Trimetric. In rhombic prisms; J A [=116° 10’. Cleavage 
 parallel with J Usually in compound crystals having the 
 form of a hexagonal prism, with uneven or striated sides ; 
 or in stellated forms consisting of two or three flat crystals 
 crossing one another. ‘Transverse sections of some of the 
 compound crystals are shown in figs. 1 to 4, | 
 
 
 
 Occurs also in, globular and coralloidal shapes; also in 
 fibrous seams in different rocks. 
 
 Color white or with light tinges of gray, yellow, green and 
 violet. Lustre vitreous. ‘Transparent to translucent. H.= 
 35-4. G.=2°9381. 
 
 Composition. Same as for calcite, and its action befor? 
 the blowpipe and with acids is the same, except that it falls 
 to powder readily when heated. Some varieties contain a 
 few per cent. of strontium carbonate, but this is not an 
 essential ingredient. Distinguished from calcite by the 
 absence of the cleavage of the latter, as well as the crystal- 
 line form ; also by its higher specific gravity. 
 
 Obs. Aragonite occurs mostly in gypsum beds and in 
 connection with iron ores; also in basalt and other rocks. 
 The coralloidal forms are found in iron ore beds, and are 
 called Flos ferri, flowers of iron. They look like a loosely 
 intertwined or tangled white cord. 
 
 The flos-ferri variety occurs at Lockport with gypsum ; 
 also at Edenville, at the Parish iron ore bed in Rossie, and 
 in Chester County, Pennsylvania. Aragon in Spain affords 
 six-sided prisms of aragonite, associated with gypsum. This 
 locality gave the name to the species. Also found at Bilin, 
 in Bohemia, Tarnowitz in Silesia, and other places. 
 
COMPOUNDS OF CALCIUM. 219 
 
 Dolomite.—Calcium-Magnesium Carbonate. Magnesian Carbonate of 
 Lime. 
 
 Rhombohedral. Rk A R=106° 15’. Cleavage perfect pa- 
 rallel to 2. Faces of rhombohedrons sometimes 
 curved, asin the annexed figure. Often granular 
 and massive, constituting extensive beds. 
 
 Color white or tinged with yellow, red, green, [/Z 
 brown, and sometimes black. Lustre vitreous or <& 
 pearly. Nearly transparent to translucent. Brit- 
 tle. H.=3°5-4, G.=2-°8-2°9. 
 
 Composition. 4CatMgO,C = Calcium carbonate 54:35, 
 magnesium carbonate 45°65=100. Some iron or manga- 
 nese is often present, replacing part of the magnesium or 
 calcium. Dolomite resembles calcite, but differs in that 
 unless finely pulverized it effervesces very sparingly, if at 
 all, in cold dilute hydrochloric acid. 
 
 The princpal varieties of this species are as follows : 
 
 Dolomite. White, crystalline granular, often not distin- 
 guishable in external characters from granular limestone. 
 
 Pearl spar. In pearly rhombohedrons with curved faces. 
 
 fthomb spar, Brown spar. In rhombohedrons, which be- 
 come brown on exposure, owing to their containing 5 to 10 
 per cent. of oxide of iron or manganese. 
 
 A cobaltiferous variety has a red tint. A white compact 
 siliceous variety has been called Gurhofite. Some hydraulic 
 limestones are dolomite. 
 
 Diff. Distinctive characters nearly the same as for cai- 
 cite. It is harder than that species, and differs in the 
 angles of its crystals, and effervesces much less freely; but 
 chemical analysis is often required to distinguish them. 
 
 Obs. Massive dolomite is common in Western New Eng- 
 land and Southeastern New York, and constitutes much 
 of the marble used for building. Crystallized specimens 
 are obtained at the Quarantine, Richmond County, N. Y. 
 Rhomb spar occurs in tale, at Smithfield, R. I.; Marlboro’, 
 Vt.; Middlefield, Mass. ; pearl spar in crystals of the above 
 form at Lockport, Niagara Falls, Rochester, Glen’s Falls ; 
 gurhofite on Hustis’s farm, Phillipstown, N. Y. 
 
 Dolomite was named in honor of the geologist and trav- 
 eler, Dolomieu. 
 
 Dolomite burns to quicklime like calcite, and affords a 
 more durable cement. The white massive variety is used 
 
 
 
220 DESCRIPTIONS OF MINERALS. 
 
 extensively as marble. The magnesian lime has been sup- 
 posed to injure soils; but this is believed not to be the case 
 if it is air-slaked before being used. It is also employed in 
 the manufacture of Epsom salts or magnesium sulphate. 
 
 Ankerite. Resembles brown spar, and, like that, becomes brown on 
 exposure. Fundamental from a rhombohedron of 106° 12. Itis a 
 calcium-magnesium-iron-and-manganese carbonate. The Styrian iron 
 ore beds of Saltzburg are some of its foreign localities. It occurs in 
 Nova Scotia, and in quartz veins in Western New Hampshire ; Quebec, 
 Canada, etc. 
 
 Hydrodolomite. A calcium-magnesium carbonate containing water. 
 Pennite from Texas, Pa., is similar. 
 
 BARIUM anp STRONTIUM. 
 
 Barium and strontium occur in nature only in anhydrous 
 ternary compounds of the following kinds: sulphate, car- 
 ponate, silicate ; and in silicates only in combination with 
 other basic elements. The species are characterized by high 
 specific gravity, ranging from 3°6 to 4°5. Strontium gives 
 a red color to the blowpipe flame ; and barium, if strontium 
 and other basic elements are absent, a characteristic green 
 color. 
 
 Barite—Heavy Spar. Barium Sulphate. 
 Trimetric. In modified rhombic and rectangular prisms, 
 
 IAT=101° 40'; OA}i=141° 08’; OA1i=127° 18’. Crys- 
 tals usually tabular. Massive 
 also columnar, fibrous, granu- 
 
 1. Pee ;, lar and compact. Lustre vitre- 
 
 J I " ous; sometimes pearly. Color 
 Bos 
 yellow, red, brown, blue, or 
 dark brown. ‘Transparent or 
 ras 
 
 3. Try 6. Composition. Ba 0, 8,= 
 
 Lily Sulphur trioxide 34:3, baryta 
 placing a little barium. B.B. 
 fuses to a bead which reacts 
 
 varieties often coarse lamellar ; 
 white and sometimes tinged 
 
 : 
 translucent. H.=2°5-3'5. G. 
 Eee : 65°7=100. Strontium and cal- 
 4, oF - cium are sometimes present re- 
 alkaline. Imparts a green color to the flame. After fusion 
 
COMPOUNDS OF BARIUM AND STRONTIUM. 1 
 
 with soda in the reducing flame on coal, and then placed 
 on a silver coin and moistened, it produces a black stain, 
 due to sulphur. 
 
 Barite is often present in mineral veins as the gangue of 
 the ore. In this way it occurs at Cheshire, Conn.; Hat- 
 field, Mass.; Rossie and Hammond, New York; Perkio- 
 men, Pennsylvania, and the lead mines of the Mississippi 
 Valley. Scoharie, and Pillar Point near Sackett’s Harbor, 
 are other localities; alsonear Fredericksburg and elsewhere, 
 Virginia ; Nova Scotia, etc. The variety from Pillar Point 
 receives a fine polish and looks like marble, the colors being 
 in bands or clouds. 
 
 Heavy spar is ground up and used to adulterate white 
 lead. When white lead is mixed in equal parts with it, 
 it is sometimes called Venice white, and another quality 
 with twice its weight of barite is called Hamburg white, 
 and another, one-third white lead, is called Dutch white. 
 When the material is very white, a proportion of it gives 
 greater opacity to the color, and protects the lead from 
 being speedily blackened by sulphurous vapors; and these 
 mixtures are therefore preferred for certain kinds of painting, 
 
 Dreelite is a barium-calcium sulphate, 
 
 Witherite.—Barium Carbonate. 
 
 Trimetric. JAZ=118° 30’. Cleavage imperfect. Also 
 in globular or botryoidal forms: often massive, and either 
 fibrous or granular. ‘The mas- 
 sive varieties have usually a yellow- 1. 2. 
 ish or grayish-white color, with a 
 lustre a little resinous, and are 
 translucent. The crystals are often 
 white and nearly transparent. H. 
 =3-4. G.=429-4°35. Brittle. 
 
 Composition. Ba O; C=Carbon 
 dioxide 22°3, baryta 77-7=100. B. 
 B. decrepitates and fuses easily, 
 tingeing the flame green, to a trans- 
 lucent globule, which becomes 
 Opaque on cooling, and colors a 
 moistened turmeric paper red. 
 Hffervesces in hydrochloric acid. 
 
 Diff. Distinguished by its spe- 
 cific gravity and fusibility from ‘calcite and aragonite; its 
 
 
 
222 DESCRIPTIONS OF MINERALS. 
 
 action with acids, from allied minerals that are not carbon- 
 ates; by yielding no metal, from cerussite, and by tingeing 
 the flame green, from strontianite. 
 
 Obs. The most important foreign localities of witherite 
 are at Fallowfield in Northumberland (where it is mined). 
 Alstonmoor in Cumberland, and Anglezark in Lancashire. 
 Itis also found in Silesia, Styria,.and Sicily. In the United 
 States it occurs at Lexington, Ky. 
 
 Witherite, from Fallowfield, is used in chemical works, in 
 the manufacture of plate glass, and in France in the manu- 
 facture of beet sugar. 
 
 Barytocaicite. Occurs at Alstonmoor in Cumberland, England, in 
 whitish monoclinic crystals. H.=4. G.=3'6-3°7. It is a barium- 
 calcium carbonate. 
 
 Bromlite is a trimetric mineral, of the same composition, from 
 Bromley Hill, near Alston, and from Northumberland, England. 
 
 Celestite.—Strontium Sulphate. 
 
 Trimetric. JA[=103° 30’ to 104° 30’. Crystals rhombic 
 prisms or tabular ; often long and slender. Cleavage dis- 
 tinct parallel with J. Mas- 
 
 sive varieties : columnar or 
 
 ye fibrous, forming layers half 
 = an inch or more thick with 
 
 (lie ore a pearly lustre ; rarely gran- 
 Cities fas boppeaer ee war. Color generally a 
 
 tinge of blue, but sometimes 
 clear white or reddish. Lus- 
 tre vitreous or a little pearly; transparent to translucent. 
 H. =3-3°5. G.==3°9-4. Very brittle. 
 
 Composition. SrO,S=Sulphur trioxide 43°6, strontia 
 56-4=100. B.B. decrepitates and fuses, tinging the flame 
 bright red to a milk-white alkaline globule, which gives 
 an alkaline reaction. With soda on coal fuses to a mass 
 which when moistened blackens silver. 
 
 Diff. From barite, which it resembles, it is distinguished 
 by the bright red color it imparts to the blowpipe fiame, and 
 its less specific gravity ; and from the carbonates, by not ef- 
 fervescing with acids. 
 
 Obs. Celestite is found in beds of sandstone or lime- 
 stone, and also with gypsum, rock salt, and clay. A bluish 
 celestine, in tabular and prismatic crystals, occurs at Stron- 
 tian Island, Lake Erie; Scoharie, Lockport and Rogssie, N, 
 
COMPOUNDS OF PCTASSIUM AND SODIUM. Fo8 
 
 Y., are other localities. A handsome fibrous variety occurs 
 at Franktown, Huntingdon County, Pennsylvania. Sicily 
 affords fine crystallizations associated with sulphur. 
 
 The pale sky-dlwe tint, so common with the mineral, gave 
 origin to the name celestite. 
 
 Celestite is used in the arts for making the nitrate of 
 strontia, which is employed for producing a red color in fire- 
 works. 
 
 Strontianite.—Strontium Carbonate. 
 
 Trimetric. JAf=117°19'. Cleavage parallel to J, near- 
 ly perfect. Occursalso fibrous and granular, and sometimes 
 in globular shapes with a radiated structure within. 
 
 Color often a light tinge of green; also white, gray, and 
 yellowish brown. Lustre vitreous, or somewhat resinous. 
 Transparent to translucent. H.=3°5-4. G.=3°6-3°72. 
 Brittle. 
 
 Composition. Sr O;C = Carbon dioxide 29°%, strontia 
 70°3=100. A small part of the strontium is often replaced 
 by calcium. B.B. swells, throws out little sprouts, but 
 does not fuse. Colors the flame bright red, and after heat- 
 ing possesses an alkaline reaction. Hffervesces in cold di- 
 lute acid; sulphuric acid gives a precipitate of strontium 
 sulphate. 
 
 Diff. Its effervescence with acids distinguishes it from 
 minerals that are not carbonates; the color of the flame 
 before the blowpipe, from witherite and all other carbon- 
 ates ; calcium salts also give a red color to the flame, but 
 the shade is yellowish, and less brilliant. 
 
 Obs. Strontianite occurs in limestone at Scoharie, N. Y., 
 in crystals, and also fibrous and massive; and in Jeffer- 
 son County, N. Y., and Mifflm County, Penn. Strontian 
 in Argyleshire, England, was the first locality known, and 
 gave the name to the mineral and the metal strontium. It 
 occurs there, with galenite, in stellated and fibrous groups 
 and in crystals. 
 
 This mineral is used for preparing the strontium nitrate. 
 
 POTASSIUM anp SODIUM. 
 
 Potassium and sodium occur in nature in the state of 
 chloride, sulphate, nitrate, and carbonate, and are constitu- 
 ents in many silicates, 
 
224 DESCRIPTIONS OF MINERALS. : 
 
 Sylvite.—Potassium Chloride. 
 
 Isometric. White or colorless, with vitreous lustre, and 
 taste nearly that of common salt. ‘The crystals are often 
 cubes with octahedral planes, like fig. 8 on p. 19. H.=2. 
 G.=1°'9-2. 
 
 Composition. K Cl=Chlorine 475, potassium 52°5=100. 
 From Vesuvius, about the fumaroles of the volcano. 
 
 Halite.—Common Salt. Sodium Chloride. 
 
 Isometric. In cubes and other related forms. Some- 
 times crystals have the shape of a shallow four-sided cup, 
 and are called hopper-shaped crystals ; they were formed 
 floating, the cup receiving its enlargement at the margin, 
 this being the part which lay at the surface of the brine 
 where evaporation was going on. Cleavage cubic, perfect. 
 
 Color usually white or grayish, sometimes rose-red, yel- 
 low, and of amethystine tints. ‘laste saline. De edie Bi 
 2°257. 
 
 Composition. NaCl=Chlorine 60°%, sodium 39°3=100. 
 Crackles or decrepitates when heated ; fuses easily, coloring 
 the flame deep yellow. 
 
 Diff. Distinguished by its taste, solubility, and blowpipe 
 characters. 
 
 Obs. Salt occurs in extensive but irregular beds, usually 
 associated with gypsum, anhydrite, and clays or sandstone. 
 It occurs in formations of all ages, from the Silurian to the 
 present time. It exists in the Pyrenees, in the valley of 
 Cardona and elsewhere, forming hills 300 to 400 feet high ; 
 in Poland and Wieliczka; at Hall in the Tyrol, and along a 
 range through Reichenthal in Bavaria, Hallein in Saltzburg, 
 Hallstadt, Ischl and Ebensee in Upper Austria, and Aussee 
 in Styria; in Hungary at Marmoros and elsewhere ; in 
 Transylvania, Wallachia, Galicia and Upper Silesia; at 
 Vie and Dieuze in France; at Bex in Switzerland ; in 
 Cheshire, England ; in Northern Africa in vast quantities 
 forming hills and extended plains ; in Northern Persia at 
 Tiflis ; in India in the province of Lahore, and in the valley 
 of Cashmere; in China and Asiatic Russia ; in South Amer- 
 ica, in Peru and the Cordilleras of New Granada. 
 
 Among the most remarkable deposits are those of Poland 
 and Hungary. The former, near Cracow, have been worked 
 since the year 1251, and it is calculated that there is still 
 
COMPOUNDS OF POTASSIUM AND SODIUM. 995 
 
 enough salt remaining to supply the whole world for many 
 centuries. Its deep subterranean regions are excavated into 
 houses, chapels and other ornamental forms, the roof being 
 supported by pillars of salt ; and when illuminated by lamps 
 and torches, they are objects of great splendor. 
 
 The salt is often impure with clay, and is purified by dis- 
 solving it in large chambers, drawing it off after it has 
 settled, and evaporating it again. The salt of Norwich (in 
 Cheshire) is in masses 5 to 8 feet in diameter, which are 
 nearly pure, and it is prepared for use by crushing it be- 
 tween rollers. 
 
 In North America, beds of rock salt exist at Goderich in 
 Canada ; at Wyoming in Western New York (reached by 
 boring to a depth of 1,279 feet) ; in Washington County, in 
 Virginia ; and extensively at Petite Anse in Louisiana, where 
 it underlies 144 acres ; in Nevada, at several localities; in 
 the Salmon River Mountains, Oregon. 
 
 Brine springs also proceed from rocks of various ages ; 
 and often they are indications of deep-seated beds of rock 
 salt. 
 
 The salt of Western New York, and Goderich, Canada, 
 ‘is of the Salina period of the Upper Silurian ; the brine 
 springs of Michigan, from shales and marlytes of the Sub- 
 carboniferous period ; those of the salt beds of Norwich, 
 dingland, in magnesian limestone of the Permian ; those of 
 the Vosges and of Saltzburg, Ischl, and the neighboring 
 regions, in marly sandstone of the Triassic ; those of Bex, 
 in Switzerland, in the Lias formation; that of Wieliczka, 
 Poland, and the Pyrenees, in the Cretaceous or chalk forma- 
 tion; that of Catalonia, in the Tertiary ; that of Louisiana, 
 in the Quaternary, and large deposits are still more recent ; 
 and besides there are lakes that are now evaporating and 
 producing salt depositions. 
 
 Vast lakes of salt water exist in many parts of the world. 
 The Great Salt Lake of Utah has an area of 2,000 square 
 miles, and is remarkable for its extent, considering that it 
 is situated toward the summit of the Rocky Mountains, at 
 an elevation of 4,200 feet above the sea. Its.waters contain 
 20 per cent. of sodium chloride (common salt). The dry 
 regions of these mountains and of Southwestern California 
 are noted for salt licks and lakes. In Northern Africa 
 large lakes as well as hills of salt abound, and the deserts 
 of this region and Arabia abound in saline efflorescences. 
 
 15 
 
226 DESCRIPTIONS OF MINERALS. 
 
 The Dead and Caspian Seas, and the lakes of Khoordistan, 
 are galt. From 20-26 per cent. of the weight of the water 
 from the Dead Sea are solid salts, of which 10 per cent. are 
 common salt. Over the pampas of La Plata and Patagonia 
 there are many ponds and lakes of salt water. ; 
 
 The greater part of the salt made in this country is ob- 
 tained by evaporation from salt springs. Those of Salina and 
 Syracuse are well known ; and many nearly as valuable are 
 worked in Ohio and other Western States. At the best New 
 York springs a bushel of salt is obtained from every 40 gal- 
 lons. But the discovery of rock salt at Wyoming, west of 
 Syracuse, may lead to further discoveries, which will make 
 the brines of New York of comparatively little value. ‘To 
 obtain the brine, wells from 50 to 150 feet deep are sunk by 
 boring. It is then raised by machinery. | 
 
 The process of evaporation under the heat of the sun is 
 extensively employed in hot climates for making salt from 
 sea water, which affords a bushel for every 300 or 350 gal- 
 lons. For this purpose a number of large shallow basins 
 are made adjoining the sea; they have a smooth bottom of 
 clay, and all communicate with one another. The water is 
 let'in at high tide and then shut off for the evaporation to 
 goon. ‘This is the simplest mode, and is used even in un- 
 civilized countries, as among the Pacific Islands. 
 
 Mirabilite.—Glauber Salt. Hydrous Sodium Sulphate. 
 
 Monoclinic. Occurs in efflorescent crusts of a white or 
 ellowish-white color; also in many mineral waters. ‘Taste 
 cool, then feebly saline and bitter. 
 
 Composition. Na,0,5+10aq = Sulphur trioxide 24°8, 
 soda 19°3, water 55°9=100. 
 
 Diff. It is distinguished from Epsom salt, for which it 
 is sometimes mistaken, by its coarse crystals, and the yel- 
 low color it gives to the blowpipe flame. 
 
 It is made in enormous amounts from common salt, its 
 production being one stage in the manufacture of sodium 
 carbonate. Ibis used in medicine, and is known by the 
 familiar name of ‘‘salts.” 
 
 Obs. On Hawaii, one of the Sandwich Islands, in a cave 
 at Kailua, Glauber salt is abundant, and is constantly form- 
 ing. It is obtained by the natives and used as medicine. . 
 Glauber salt occurs in efflorescences on the limestone below 
 
COMPOUNDS OF POTASSIUM AND SODIUM. 997 
 
 Genesee Falls, near Rochester, N.Y. It is also obtained in 
 Austria, Hungary, and elsewhere in Europe. 
 
 The artificial salt was first discovered by a German 
 chemist by the name of Glauber. 
 
 Aphthitalite (Arcanite). Potassium sulphate, K,0,8=Sulphate tri- 
 oxide 459, potash 54:1—100. Found at Vesuvius. Misenite is a hy- 
 drous potassium sulphate from a cavern near Misene. 
 
 Thenardite. Sodium sulphate Na,O,S=Sulphur trioxide 43:7, 
 soda 56°3=100. From Spain, Bolivia, Tarapaca, in Peru; Slate Range, 
 San Bernardino Co., California ; and in Nevada. 
 
 Glauberite. Sodium-calcium sulphate. In monoclinic crystals, at 
 Villa Rubia, in New Castile, Aussee, in Austria, and other salt beds. 
 
 Polyhalite and Picromeride are hydrous magnesium-potassium sul- 
 phates ; Bledite and Loweite hydrous magnesium-sodium sulphates ; 
 Syngenite, a hydrous calcium-potassium sulphate. 
 
 Borax.—Hydrous Sodium Biborate. Tinkal. 
 
 Monoclinic. In oblique rhombic prisms J A J=87°. Cleay- 
 age parallel with 7-7 perfect. The crystals are white and 
 trausparent, with a glassy lustre. H.=2-2'5. G.=1°716. 
 Taste sweetish-alkaline. 
 
 Composition. Na, O,B,+10aq=Boron trioxide 36°6, soda 
 16°2, water 47-°2=100. B.B. swells up to many times its 
 bulk and becomes opaque white, and finally fuses to a 
 glassy globule. 
 
 Ods. Borax was originally brought from a salt lake in 
 Thibet, where it is dug in considerable masses from the 
 edges and shallow parts of the lakes. The holes thus made 
 in a.short time become filled again with borax. The crude 
 borax was formerly sent to Europe under the name of ¢in- 
 kal, and there purified for the arts. It has also been found 
 in Peru and Ceylon. It has been extensively made from the 
 boracic acid of the Tuscan lagoons by the reaction of this 
 acid on sodium carbonate. 
 
 Borax occurs under like circumstances in California and 
 Nevada, or is manufactured from other borates in solution 
 or in the solid state. Localities in California are Borax 
 Lake and its vicinity, north of San Francisco; also near 
 Walker’s Pass, Sierra Nevada; at Mono and Owens Lakes, 
 and at Death Valley, near the borders of Nevada; in 
 the Slate Range, in San Bernardino County; and in 
 Nevada, at Little Salt Lake, near Ragtown, on the Pacific 
 Railroad, and at Columbus Marsh. The Columbus Marsh, 
 in Neyada, near lat. 88° 5'N. and long. 118° W., 46 miles 
 
228 DESCRIPTIONS OF MINERALS. . 
 
 north of trail from Mono Lake, isa deposit, 10 miles long 
 by 7 wide, of borates and other salts, chiefly borax, calcium 
 borate, sodium sulphate, and common salt. The large de- 
 posits of ‘ priceite” in Southern Oregon, and of ulexite, in 
 the ‘* Cane Spring District,” 20 miles west of San Bernar- 
 dino, and at the Columbus Marsh, are other sources of 
 >orax. The amount of borax received at San Francisco 
 during the year 1876 was 5,180,910 pounds, and in 1877, 
 4,154,209 pounds. 
 
 Nitre.—Potassium Nitrate. 
 
 Trimetric. In modified right rhombic prisms. patie 
 118° 50’. Usually in thin white subtransparent crusts, and 
 in needleform crystals on old walls and in caverns. ‘Taste 
 saline and cooling. H=2. G=1°9%7. 
 
 Composition. K,O; N=Nitrogen pentoxide (N, O;) 53:4, 
 potash 46°6. Burns vividly on a live coal. 
 
 Diff. Distinguished readily by its taste and its vivid ac- 
 tion on a live coal; and from sodium nitrate, which it most 
 resembles, by its not becoming liquid on exposure to the 
 
 it 
 
 Nitre, called also saltpetre, 1s employed in making gun- 
 powder, forming 75 to 78 per cent. in shooting powder, and 
 62 in mining powder. The other materials are sulphur (10 
 per cent., for shooting powder to 20 for mining) and char- 
 coal (12 to 14 for shooting powder and 18 for mining). It 
 ig also extensively used in the manufacture of nitric and 
 sulphuric acids ; also for pyrotechnic purposes, fulminating 
 powders, and sparingly in medicine. 
 
 Obs. Occurs in many of the caverns of Kentucky and 
 other Western States, scattered through the earth that 
 forms the floor of the cave. In procuring it, the earth 1s 
 lixiviated, and the lye, when evaporated, yields the nitre. 
 India is its most abundant locality, where it is obtained 
 largely for exportation. 
 
 Spain and Egypt also afford large quantities of nitre for 
 commerce. This salt forms on the ground in the hot weather 
 succeeding copious rains, and appears in silky tufts or efflo- 
 rescences; these are brushed up by a kind of broom, lix1- 
 viated, and after settling, evaporated and crystallized. In 
 France, Germany, Sweden, Hungary, and other countries, 
 there are artificial arrangements called nitriartes or nitre 
 beds, from which nitre is obtained by the decomposition 
 
 \ 
 
COMPOUNDS OF POTASSIUM AND SODIUM. 229 
 
 mostly of the nitrates of lime and magnesia which form in 
 these beds. Refuse animal and vegetable matter putrefied 
 in contact with calcareous soils produces nitrate of lime, 
 which affords the nitre by reaction with carbonate of pot- 
 ash. Old plaster lixiviated affords about 5 per cent. This 
 last method is much used in France. The nitric acid of 
 the cavern nitrates comes from the atmosphere, which also 
 consists of nitrogen and oxygen ; but the combination takes 
 place through the agency of a peculiar kind of microscopic 
 plant. 
 
 Nitratine.—Soda Nitre. Sodium Nitrate. Cubic Nitre. 
 
 Rhombohedral ; R: R=106° 33’. Also in crusts or efflo- 
 rescences, of white, grayish and brownish colors. Taste 
 cooling. Soluble and very deliquescent. 
 
 Composition. Na,.O; N=Nitrogen pentoxide 63°, soda 
 36°5=100. Burns vividly on coal, with a yellow light. 
 
 _ Diff. It resembles nitre (saltpetre), but deliquesces, and 
 gives a deep yellow hight when burning. 
 
 Obs. In the district of Tarapaca, Northern Chili, the 
 dry Pampa for an extent of forty leagues is covered with 
 beds of this salt, mixed with gypsum, common salt, glauber 
 salt, and remains of recent shells. 
 
 It is used extensively in the manufacture of nitric acid. 
 It is also used in making nitre by replacing the sodium by 
 potassium. In 1866, one million quintals of this salt were 
 exported from Chili. 
 
 Natron.—Hydrous Sodium Carbonate. Carbonate of Soda. 
 
 Monoclinic. Generally in white efflorescent crusts, some- 
 times yellowish or grayish. ‘Taste alkaline. Hffloresces on 
 exposure, and the surface becomes white and pulverulent. 
 
 Composition. Na,O;C+10aq=Carbon dioxide 26°7, soda 
 18°8, water 54°5=100. LEffervesces strongly with acids. 
 
 Diff. Distinguished from other soda salts by efferves- 
 cing, and from trona, by efflorescing on exposure. 
 
 Obs. This salt is found in solution in certain waters, 
 from which it is crystallized in efflorescences by evapora- 
 tion. Abundant in the soda lakes of Egypt; also in lakes 
 at Debreczin, in Hungary; in Mexico, north of Zacatecas, 
 and elsewhere. Sparingly dissolved in the Seltzer and 
 Carlsbad waters. 
 
230 DESCRIPTIONS OF MINERALS. 
 
 This salt (but the artificially prepared) is extensively 
 used in the manufacture of soap and glass, and for many 
 other purposes. 
 
 Trona. A hydrous sodium sesquicarbonate occurs in the province 
 of Suckenna, in Africa, between Tripoli and Fezzan, where it forms a 
 fibrous layer an inch thick beneath the soil. It is abundant at a lake 
 in Maracaibo, 48 miles from Mendoza ; and forms an extensive bed in 
 Churchill County, Nevada. 
 
 Thermonatrite. A hydrous sodium carbonate of the formula Na, 
 O,C+aq. An anhydrous sodium carbonate is stated to exist native. 
 
 Gay-Lussite. Occurs in white brittle monoclinic crystals. Com- 
 position +Na}Ca O, C+23aq. From Lagunilla, in Maracaibo, and Lit- 
 tle Salt Lake, near Ragtown, in Nevada. 
 
 AMMONIUM. 
 
 The salts of ammonia are more or less soluble in water, — 
 and are entirely and easily volatilized before the blowpipe. 
 When treated with caustic lime or potassa, ammonia is lib- 
 erated, and is recognized by its odor and the reaction of the 
 vapors on test papers. 
 
 Salmiak.—Sal Ammoniac, Ammonium Chloride. 
 
 Occurs in white crusts or efflorescences, often yellowish 
 or gray. Crystallizes in regular octahedrons. ‘Translucent 
 —opaque. Taste saline and pungent. Soluble in three parts 
 of water. 
 
 Composition. N H,C1=Chlorine 66°3, ammonium 33°7= 
 100. Gives off the odor of ammonia when powdered and 
 mixed with quicklime. 
 
 Obs. Occurs in many volcanic regions, as at Etna, Vesu- 
 vius, and the Sandwich Islands, where it is a product of 
 voleanic action. Occasionally found about ignited coal 
 seams. 
 
 The sal ammoniac of commerce is manufactured from 
 animal matter or coal soot. It is generally formed in chim- 
 neys of both wood and coal fires. In Egypt, whence the 
 greater part of this salt was formerly obtained, the fires of 
 the peasantry are made of the dung of camels ; and the soot 
 which contains a considerable portion of the ammoniacal 
 salt is preserved and carried in bags to the works, where-it 
 is obtained by sublimation. Bones and other animal mat- 
 ters are used in France. A liquid condensed in the gas 
 works, is also used in its production. 
 
WATER. 231 
 
 It is a valuable article in medicine, and is employed by 
 tinmen in soldering to prevent the oxidation of copper sur- 
 faces ; also in a variety of metallurgical operations. 
 
 Mascagnite. A hydrous ammonium sulphate. In mealy crusts, 
 of a yellowish-gray or lemon-yellow color ; translucent ; taste pungent 
 and bitter. Composition (N H,).0,8+H,O=Sulphur trioxide 53:3, 
 ammonia 22°8, water 23°9. Easily soluble in water. Occurs at Etna, 
 Vesuvius, and the Lipari Islands. It is one of the products from the 
 combustion of anthracite coal. 
 
 Lecontite is hydrous ammonium-sodium sulphate. Boussingaultite 
 is a hydrous ammonium-magnesium sulphate, from Tuscany. 
 
 Struvite. A hydrous ammonium-magnesium phosphate ; occurring 
 in yellowish crystals, slightly soluble in water; found on the site 
 of an old church in Hamburg, where there had been quantities of cat- 
 tle dung. 
 
 Tschermigite. An ammonia alum from Tschermig, Bohemia, and 
 Utah County, Utah. 
 
 Larderellite. A white tasteless ammonium borate, from the Tuscan 
 Jagoons. 
 
 Hydrous ammonium phosphate and Ammonium bicarbonate (Tesche- 
 macherite) have been detected in guano; also, Hydrous sodium-am- 
 monium phosphate, called Stercorite. 
 
 HYDROGEN. 
 Hydrogen is the basic constituent in hydrochloric acid, 
 
 and in water. 
 Hydrochloric Acid.—Muriatic Acid. 
 
 A gas, consisting of Chlorine 97:26, hydrogen 2°74—100 
 =HCl. It has a pungent odor, and is acrid to the skin. 
 
 It is rapidly dissolved by water. If passed into a solution 
 of nitrate of silver, it produces a white precipitate which 
 soon blackens on exposure. It is given out whenever com- 
 mon salt is acted on by sulphuric acid, and occasionally by 
 volcanoes. 
 
 WATER. 
 
 Water (hydrogen oxide) is the well-known liquid of 
 streams and wells. The purest natural water is obtained by 
 melting snow, or receiving rain in a clean glass vessel ; but 16 
 is absolutely pure only when procured by distillation. It 
 consists of hydrogen 1 part by weight, and oxygen 8 parts, 
 or hydrogen 11°11, oxygen 88°389=100. It becomes solid at 
 32° Fahrenheit (or 0° Centigrade), and then crystallizes, 
 ‘and constitutes ice or snow. The crystals are of the hex- 
 agonal system. Flakes of snow consist of a congeries of 
 
ROR DESCRIPTIONS OF MINERALS, 
 
 minute crystals, and stars, like the figures on page 4, may 
 often be detected with a glass. Various other allied forms 
 are also assumed. The rays meet at an angle of 60°, and 
 the branchlets pass off at the same angle with perfect regu- 
 larity. The density of water is greatest at 39° 2° F.; below 
 this it expands as it approaches 32°, owing to incipient 
 crystallization, and in the state of ice it is only 0°920. It 
 boils at 212° F. A cubic inch of pure water at 62° F. and 30 
 inches of the barometer, weighs 252°458 grains, which equals 
 16-386 grams; and a cubic foot of water weighs 62355 
 pounds avoirdupois. A pint, United States standard mea- 
 sure, holds just 7,342 troy grains of water, which is little 
 above a pound avoirdupois (7,000 grains troy). 
 
 Water, as it occurs on the earth, contains some atmo- 
 spheric air, without which the best would be unpalatable. 
 This air, with some free oxygen also present, is necessary 
 to the life of aquatic animals, In most spring water there 
 isa minute proportion of salts of calcium (sulphate, chloride 
 or carbonate), often with a trace of common salt, carbonate 
 of magnesiumand some alumina, iron, silica, phosphoric acid, 
 carbonic acid, and certain vegetable acids. These impuri- 
 ties constitute usually from +5 to 10 parts, in 10,000 parts 
 by weight. The water of Long Pond, near Boston, con- 
 tains about $a part in 10,000 ; the Schuylkill of Philadel- 
 phia, about 1 part in 10,000 ; the Croton, used in New York 
 city, 1 to 14 parts in 10,000. Nitric acid is usually found 
 in rain water combined with ammonia; river waters are 
 ordinarily the purest of natural waters, unless they have 
 flowed through a densely populated region. 
 
 Sea water contains from 32 to 37 parts of solid substances 
 in solution in 1,000 parts of water. The largest amount in 
 the Atlantic, 36°6 parts, is found under the equator, away 
 from the land or the vicinity of fresh-water streams ; and 
 the smallest in narrow straits, as Dover Straits, where there 
 are only 32°5 parts. In the Baltic and Black Seas, the pro- 
 portion is only one-third that in the open ocean. Of the 
 whole, one-half to two-thirds is common salt (sodinm chlo- 
 ride). The other ingredients are magnesium salts (chloride 
 and sulphate), amounting to four-fifths of the remainder, 
 with sulphate and carbonate of calcium, and traces of bro- 
 mides, iodides, phosphates, borates and fluorides. ‘The water 
 of the British Channel affords water 964°7 parts in 1,000, 
 sodium chloride 27°1, potassium chloride 0°8, magnesium 
 
axe } 
 
 SILICA. 209 
 
 chloride 3°7, magnesium sulphate 2'30, calcium sulphate 
 1-4, calcium carbonate 0:03, with some magnesium bromide 
 and probably traces of iodides, fluorides, phosphates and 
 borates. ‘The bitter taste of sea water is owing to the salts 
 of magnesium present. 
 
 I'he waters of the Dead Sea contain 200 to 260 parts of 
 solid matter in 1,000 parts (or 20 to 26 per cent.), including 
 7 to 10 per cent. of common salt, the same proportion of 
 magnesian salts, principally the chloride, 24 to 34 per cent. 
 of calcium carbonate and sulphate, besides some bromides 
 and alumina. ‘The density of these waters is owing to this 
 large proportion of saline ingredients. The brine springs 
 of New York and other States south and west, are well- 
 known sources of salt (see under Common salt). Many of 
 the springs afford bromine, and large quantities of it are 
 manufactured for making photographic plates and for other 
 purposes. 
 
 Mineral waters vary much in constitution. They often 
 contain iron in the state of bicarbonate, like those of Sara- 
 toga and Ballstown, and are then called chalybeate waters, 
 from the ancient name for iron or steel, chalybs, derived 
 from the name of a country on the Baltic. Hydrogen sul- 
 phide is often held in mineral waters and imparts to them 
 its odor and taste; such are the so-called sulphur springs. 
 
 Minute traces of salts of zinc, arsenic, lead, copper, an- 
 timony and tin, have been found in some waters. What- 
 ever is soluble in a region through which waters flow, will 
 of course be taken up by them, and many ingredients are 
 soluble in minute proportions, which are usually described 
 as insoluble. 
 
 Til. SILICA AND SILICATES. 
 I. SILICA. 
 
 Quartz. 
 
 Rhombohedral. Occurs usually in six-sided prisms, more 
 or less modified, terminated with six-sided pyramids : KA FL 
 =94° 15’. No cleavage apparent, seldom even in traces ; 
 but sometimes obtained by heating the crystal and plunging 
 it into cold water. Sometimes in coarse radiated forms; 
 
234 DESCRIPTIONS OF MINERALS. 
 
 also coarse and fine granular; also compact, either amor- 
 phous, or presenting stalactitic and mammillary shapes. 
 Crystals often as pellucid as glass, and colorless; some- 
 times topaz-yellow, amethystine, rose, smoky, or other tints. 
 Also of all degrees of transparency to opaque, and of various 
 shades of yellow, red, green, blue and brown colors to black. 
 In some varieties the colors are in bands, stripes, or clouds. 
 
 HiT, G. =2°5-2'8. 
 4, 5. 
 i & 
 gh Qy” 
 
 Composition. SiO,.=Oxygen 53°33, silicon 46°67=100. 
 Opaque varieties often contain oxide of iron, clay, chlorite, 
 or some other mineral disseminated through them. B.B. 
 infusible. With soda, fuses with effervescence. 
 
 Diff. Quartz is exceedingly various in color and form, 
 but may be distinguished, by (1) absence of true cleavage ; 
 (2) its hardness; (3) its infusibility before the blowpipe ; 
 (4) its insolubility with either of the common acids; (5) its 
 effervescence when heated B.B. with soda; and (6) when 
 crystallized, by the forms of its crystals, which are almost 
 always six-sided prisms terminating in six-sided pyramids. 
 
 The varieties of quartz owe their peculiarities either to 
 crystallization, mode of formation, or impurities, and they 
 fall naturally into three series. 
 
 I. The vitreous varieties, distinguished by their glassy 
 fracture. 
 
 Il. The chalcedonic varieties, having a subvitreous or a 
 waxy lustre, and generally translucent. 
 
 IIL. The jaspery cryptocrystalline varieties, having barely 
 a glimmering lustre or none, and opaque. 
 
 I. VITREOUS VARIETIES. 
 
 Rock Orystal. Pure pellucid quartz. 
 
 This is the mineral to which the word crystal was first 
 applied by the ancients ; it is derived from the Greek krus- 
 tullos, meaning ice. The pure specimens are often cut and 
 used in jewelry, under the name of ‘ white stone.” 
 
 It is often used for optical instruments and spectacle 
 
 
 
SILICA. 935 
 
 glasses, and even in ancient times was made into cups and 
 vases. Nero is said to have dashed to pieces two cups of 
 this kind on hearing of the revolt that caused his ruin, one 
 of which cost him a sum equal to $3,000. 
 
 Amethyst. Purple or bluish-violet, and often of great 
 beauty. The color is owing to a trace of manganese oxide. 
 It was called amethyst on account of its supposed preser- 
 vative powers against intoxication. When finely and uni- 
 formly colored, highly esteemed as a gem. 
 
 Rose Quartz. Pink or rose-colored. Seldom occurs in 
 crystals, but generally in masses much fractured, and im- 
 perfectly transparent. ‘The color fades on exposure to the 
 light, and on this account it is little used as an ornamental 
 stone, yet is sometimes cut into cups and vases. 
 
 False Topaz. Light yellow pellucid crystals. They are 
 often cut and set for topaz. ‘The absence of cleavage dis- 
 tinguishes it from true topaz. The name citrine, often ap- 
 plied to this variety, alludes to its yellow color. 
 
 Smoky Quartz. Crystals of a smoky tint; the color is 
 sometimes so dark as to be nearly black and opaque except 
 in splinters. It is the cairngorm stone. 
 
 Milky Quartz. Milk-white, nearly opaque, massive, and 
 of common occurrence. It has often a greasy lustre, and is 
 then called greasy quartz. 
 
 Prase. leek-green, massive ; resembling some shades of 
 beryl in tint, but easily distinguished by the absence of 
 cleavage and its infusibility. Supposed to be colored by a 
 trace of iron silicate. 
 
 Aventurine Quartz. Common quartz spangled through- 
 out with scales of golden-yellow mica. It is usually trans- 
 lucent, and gray, brown, or reddish brown in color. 
 
 Ferruginous Quartz. Opaque, and either of yellow, 
 brownish-yellow, or red color. The color is due to the 
 presence of iron oxide as an impurity, the red to the anhy- 
 drous oxide, and the brownish yellow to the hydrous oxide. 
 
 II. CHALCEDONIC VARIETIES. 
 
 Chalcedony. ‘Translucent, massive, with a glistening and 
 somewhat waxy lustre; usually of a pale grayish, bluish, or 
 light brownish shade. Often occurs lining or filling cavities 
 in amygdaloidal rocks, and sometimes in other kinds. These 
 cavities are nothing but little caverns, into which siliceous 
 waters have filtrated at some period. The stalactites are 
 
236 DESCRIPTIONS OF MINERALS. 
 
 “icicles” of chalcedony, hung from the roof of the cavity. 
 Some of these chalcedony grottos are several feet _in dia- 
 meter. Large geodes of this kind occur in the Keokuk 
 limestone in Ilinois and Iowa. 
 
 sant pestis Apple-green chalcedony. It is colored by 
 nickel. 
 
 Carnelian. A bright red chalcedony, generally of a clear 
 rich tint. It is cut and polished and much used in the more 
 common jewelry. It is often cut for seals and beads. 
 
 Sard. A deep brownish-red chalcedony, of a blood-red 
 color by transmitted light. 
 
 Agate. A variegated chalcedony. The colors are dis- 
 tributed in clouds, spots, or concentric lines. These lines 
 take straight, circular, or zigzag forms ; and when the last 
 it is called fortification agate, so named from the resem- 
 plance to the angular outlines of a fortification. These lines 
 are the edges of layers of chalcedony, and these layers are 
 the successive deposits during the process of its formation. 
 Mocha stone or Moss agate is a brownish agate, consisting 
 of chalcedony with dendritic or moss-like delineations, of an 
 opaque yellowish-brown color. They arise from dissem- 
 inated iron oxide. All the varieties of agate are beautiful 
 stones when polished, but are not much used in fine jewelry. 
 The colors may be darkened by boiling the stone in oil, and 
 then dropping it into sulphuric acid ; a little oil is absorbed. 
 by some of the layers, which becomes blackened or charred 
 by the acid. 
 
 Onyx. A kind of agate haying the colors arranged in 
 flat horizontal layers; the colors are usually light clear 
 brown and an opaque white. When the stone consists of 
 sard and white chalcedony in alternate layers, it is called 
 sardonyx. Onyx is the material used for cameos, and is 
 well fitted for this kind of miniature sculpture. The figure 
 is carved out of one layer and stands in relief on another. 
 A noted ancient cameo is the Mantuan vase at Brunswick. 
 It was cut from a single stone, and has the form of a cream- 
 pot, about 7 inches high and 23 broad. On its outside, 
 which is of a brown color, there are white and yellow groups 
 of raised figures, representing Ceres and Triptolemus in 
 search of Proserpine. 
 
 Cat’s Eye is grecnish-gray translucent chalcedony, hay- 
 ing a peculiar opalescence, or glaring internal reflections, 
 like the eye of a cat, when cut with a spheroidal surface. 
 
SILICA. Rar 
 
 The effect is owing to filaments of asbestus. It comes from 
 Ceylon and Malabar, ready cut and polished, and is a gem 
 of considerable value. 
 ’ Flint, Hornstone. Massive compact silica, of dark shades 
 of smoky gray, brown, or even black, and feebly translucent, 
 it breaking with sharp cutting edges and a conchoidal sur- 
 face. Flint occurs in nodules of chalk: not unfrequently the 
 nodules are in part chalcedonic. Hornstone differs from 
 flint in being more brittle ; it is often found in limestone. 
 Chert is an impure hornstone. Limestones containing 
 hornstone or chert are often called cherty limestone. 
 Plasma. A faintly translucent variety of chalcedony ap- 
 proaching jasper, of a green color, sprinkled with yellow 
 and whitish dots. . 
 
 Ill. JASPERY VARIETIES. 
 
 Jasper. A dull red or yellow siliceous rock, containing 
 some clay and yellow or red iron oxide, the red, the anhy- 
 drous oxide, and the yellow, the hydrous oxide. Heat drives 
 off the water from the yellow jasper and turns it red. It 
 also occurs of green and other shades. iband jasper is a 
 jasper consisting of broad stripes of green, yellow, gray, 
 red, or brown. Lyyptian jasper consists of these colors in 
 irregular concentric zones, and occurs in nodules, which 
 are often cut across and polished. win jasper is a variety 
 with delineations like ruins, of some brownish or yellowish 
 shade on a darker ground. Porcelain jasper is nothing but 
 a baked clay, and differs from jasper in being fusible before 
 the blowpipe. Red felsyte resembles red jasper; but this 
 is also fusible, and consists largely of feldspar. 
 
 Jasper admits of a high polish, and is a handsome stone 
 for inlaid work, but is not much used as a gem. 
 
 Bloodstone or Heliotrope. Deep green, slightly trans- 
 lucent, containing spots of red, which have some resem- 
 blance to drops of blood. It contains a few per cent. of 
 clay and iron oxide mechanically combined with the silica. 
 The red spots are colored with iron. There is a bust of 
 Christ in the royal collection at Paris, cut in this stone, in 
 which the red spots are so managed as to represent drops 
 of blood. 
 
 Lydian Stone, Touchstone, Basanite. Velvet-black and 
 opaque, and used, on account of its hardness and black 
 color, for trying the purity of the precious metals; this 1s 
 
238 DESCRIPTIONS OF MINERALS, 
 
 done by comparing the color of the mark left on it with 
 that of an alloy of known character. The effect of acids 
 upon the mark 1s also noted. 
 
 Besides the above there are other varieties arising from 
 structure. 
 
 Tabular Quartz. Consists of thin plates, either parallel 
 or crossing One another and leaving large open cells. 
 
 Granular Quartz. A rock consisting of quartz erains 
 compactly cemented. ‘The colors are white, gray, flesh-red, 
 yellowish or reddish-brown. It is a hard siliceous sand- 
 stone. Ordinary sandstone often consists of nearly pure 
 quartz. 
 
 Pseudomorphous Quartz. Quartz under the forms of cal- 
 cite, barite, fluorite or other mineral. Shells, corals, etc., 
 are sometimes found converted into quartz by the ordinary 
 process of petrifaction. 
 
 Silicified Wood. Petrified wood often consists of quartz, 
 quartz having taken the place of the original wood. Some 
 specimens are petrified with chalcedony or agate. 
 
 Penetrating substances. Quartz crystals are sometimes 
 penetrated by other minerals. Rutile, asbestus, actinolite, 
 topaz, tourmaline, chlorite and epidote, are some of these 
 substances. The rutile often looks like needles or fine 
 hairs of a brown color passing through in every direc- 
 tion. They are cut for jewelry, and in France pass by the 
 name of Fiéches d’amour (love’s arrows). ‘The crystals of 
 Herkimer County, N. Y., often contain a kind of black coal. 
 Other crystals contain cavities filled with some fluid, as 
 water, naphtha, or liquid carbonic acid, or with minute 
 crystals. 
 
 Obs. Quartz is an essential constituent of granite, gneiss, 
 mica schist, and many other common rocks, and the chief 
 or only constituent of many sandstones, and of the sands 
 of most sea-shores. Fine quartz crystals occur in Herki- 
 mer County, New York, at Middlefield, Little Falls, Salis- 
 bury and Newport, in the soil and in cavities in a sand- 
 stone. The beds of iron ore at Fowler and Hermon, St. 
 Lawrence County, afford dodecahedral crystals. Diamond 
 Island, Lake George, Pelham and Chesterfield, Mass., Paris 
 and Perry, Me., Meadow Mt., Md., and Hot Springs, Ar- 
 kansas, are other localities. Rose quartz is found at Albany 
 and Paris, Me., Acworth, N. H., and_ Southbury, Conn. ; 
 smoky quartz at Goshen, Mass.; Paris, Me.; in North Caro- 
 
SILICA. i 939 
 
 lina; at Pike’s Peak, Colorado, and elsewhere; amethyst at 
 Bristol, R. 1., and Keweenaw Point, Lake Superior ; chalce- 
 dony and agates of moderate beauty near Northampton, 
 and along the trap of the Connecticut Valley-——but finer 
 near Lake Superior, upon some of the Western rivers, and 
 in Oregon ; chrysoprase occurs at Belmont’s lead mine, St. 
 Lawrence County, N. Y., and a green quartz (often called 
 chrysoprase) at New Fane, Vt, along with fine drusy 
 quartz ; red jasper occurs on the banks of the Hudson at 
 Troy; yellow jasper is found with chalcedony at Chester, 
 Mass. ; Heliotrope occupies veins in slate at Bloomingrove, 
 Orange County, N. Y. 
 
 Switzerland, Dauphiny, Piedmont, the Carrara quarries, 
 and numerous other foreign localities furnish fine crystals. 
 
 Opal. 
 
 Compact and amorphous ; also in reniform and stalactitic 
 shapes; also earthy. Presents internal reflections, often of 
 several colors in the finest varieties, exhibiting, when turned 
 in the hand, a rich play of colors of delicate shades. White, 
 yellow, red, brown, green and gray are some of the shades 
 that occur, and impure varieties are dark and opaque. 
 Lustre subvitreous. H.=5:5-6°5. G.=1°9-2°3. 
 
 Composition. Opal consists of silica, like quartz; but it 
 is silica in a different molecular state, the hardness and 
 specific gravity being less; and, besides this, it is soluble in 
 a strong alkaline solution, especially if heated. It usually con- 
 tains a few per cent. of water—amounting in some kinds to 
 12 per cent.; but the water is not generally regarded as an 
 essential constituent. 
 
 VARIETIES. 
 
 Precious Opal. External color usually milky, but within 
 there is a rich play of delicate tints. This variety forms a 
 gem of rare beauty. A large mass in the imperial cabinet 
 of Vienna weighs seventeen ounces, and is nearly as large 
 as a man’s fist, but contains numerous fissures and is not 
 entirely disengaged from the’matrix. This stone was well 
 known to the ancients and highly valued by them. They 
 called it Paideros, or Child Beautiful as Love. 'The noble 
 opal is found near Cashau in Hungary, and in Honduras, 
 South America; also on the Faroe Islands. 
 
 Fire Opal, Girasol, An opal with yellow and bright hya- 
 
240 DESCRIPTIONS OF MINERALS. 
 
 cinth or fire-red reflections. It comes from Mexico and the 
 Faroe Islands. 
 
 Common Opal, Semiopal. Common opal has the hardness 
 of opal and is easily scratched by quartz, a character which 
 distinguishes it from some siliceous stones often called semi- 
 opal. It has sometimes a milky opalescence, but does not 
 reflect a play of colors. The lustre is slightly resinous, and 
 the colors are white, gray, red, yellow, bluish, greenish to 
 dark grayish-green. Translucent to nearly opaque. Phillips 
 found nearly 8 per cent. of water in one specimen. 
 
 Hydrophane. This variety is opaque white or yellowish 
 when dry, but becomes translucent and opalescent when 
 immersed in water. 
 
 Cacholong. Opaque white, or bluish white, and usually 
 associated with chalcedony. Much of what is so called is 
 nothing but chalcedony; but other specimens contain water, 
 and are allied to hydrophane. It contains also a little alu- 
 mina and adheres to the tongue. It was first brought from 
 the river Cach in Bucharia. 
 
 Hyalite, Muller’s Glass. A glassy transparent variety, oc- 
 curring in small concretions and occasionally stalactitic. 
 It resembles somewhat a transparent gum arabic. Composi- 
 tion, Silica 92:00, water 6°33 (Bucholz). 
 
 Menilite. A brown opaque variety, in compact reniform 
 masses, occasionally slaty. Composition, Silica 85°5, water 
 11:0 (Klaproth). It is found in slate at Menil Montant, 
 near Paris. 
 
 Wood Opal. An impure opal, of a gray, brown or black 
 color, having the structure of wood, and looking much like 
 common silicified wood. It is wood petrified with a hy- 
 drated silica (or opal), instead of pure silica, and is distin- 
 guished by its lightness and inferior hardness. Specific 
 gravity, 2. 
 
 Opal Jasper. Resembles jasper in appearance, and con- 
 tains a few per cent. of iron ; but it is not so hard, owing to 
 the water it contains. 
 
 Siliceous Sinter has often the composition of opal, though 
 sometimes simply quartz. The name is given to a loose, 
 porous siliceous rock usually of a grayish color. It is de- 
 posited around the Geysers of Iceland and the Yellowstone 
 Park, in cellular or compact masses, sometimes in fibrous, 
 stalactitic, or cauliflower-like shapes. It is often called gey- 
 serite. Pearl sinter, or fiorite, occurs in volcanic tufa in 
 
SILICA. 241 
 
 smooth and shining globular, botryoidal masses, having a 
 pearly lustre. 
 
 Float Stone. A variety of opal having a porous and fibrous 
 texture, and hence so light that it will float on water. It 
 occurs in concretionary or tuberose masses, which often 
 have a nucleus of quartz. 
 
 Tripolite, or Infusorial Harth. A white or grayish-white 
 earth, made mainly of siliceous secretions of microscopic 
 plants called Diatoms. It forms beds of considerable extent, 
 and often occurs beneath peat. It is used as a polishing 
 powder ; also to mix with nitroglycerine and make dynamite ; 
 and, owing to its poor conduction of heat, it is applied as a 
 protection to steam boilers and pipes. 
 
 Tabasheer is a siliceous aggregation found in the joints of 
 the bamboo in India. It contains several per cent. of water, 
 and has nearly the appearance of hyalite. 
 
 Diff. Infusibility before the blowpipe is the best charac- 
 ter for distinguishing opal from pitchstone, pearlstone, and 
 other species it resembles. ‘The absence of anything like 
 cleavage or crystalline structure is another characteristic. 
 Its inferior hardness and specific gravity separates it from 
 quartz. 
 
 Obs. Hyalite occurs sparingly at the Phillips ore bed, 
 Putnam County, N. Y., andin Burke and Scriven counties, 
 Georgia. In Washington County, Ga., good fire opal is 
 obtained. ‘The Suanna Spring in Georgia affords small 
 quantities of siliceous sinter. Tripolite occurs in Maine, 
 New Hampshire, Nevada, California, and elsewhere. 
 
 Tridynute. Pure silica, like quartz and opal, with very nearly the 
 hardness and specific gravity of opal, but occurring in tabular hexag- 
 onal prisms, which are twins under the triclinic system. If not crys- 
 tallized opal, it is a third state of SiO,. It occurs in trachytic and 
 some other volcanic rocks. Asmanite is from a meteorite, and may be 
 the same as tridymite. 
 
 Jenzschite. Silica, SiO,, in, it is supposed, a fourth state, it resem- 
 bling opal in aspect and in solubility in alkaline solutions, but having 
 the specific gravity of quartz, or 26. From Hittenberg in Carinthia, 
 resembling a white cachalong ; from near Weissig ; Regensberg ; and 
 in Brazil. 
 
 Melanophlogite. Colorless cubes consisting of silica, with a little 
 sulphuric trioxide and water, On sulphur from Girgenti, Sicily. 
 
 16 
 
942 DESCRIPTIONS OF MINERALS, 
 
 II. SILICATES. 
 
 The silicates are here divided into the anhydrous and 
 the hydrous. 
 
 In part of the anhydrous silicates, the combining value 
 (or quantivalence, see page 77) of the silicon is to that of 
 the basic elements as 2 to 1; in another part, as 1 to is 
 and in a third division, as less-than-1 to 1. On this ground 
 the mineral silicates may be arranged in three groups, 
 named respectively: I. BISILICATES ; II. UNISILICATES ; 
 and JII. SUBSILICATES. 
 
 In the Bisilicates, one molecule of silicon is combined 
 with one molecule of an element in the protoxide state, as 
 Mg, Ca, Fe, etc., or one-third of a molecule of an element 
 in the sesquioxide state, as Al, Fe, Mn, etc.; or, what is 
 the same thing, 3 molecules of silicon, with 3 of an element 
 in the protoxide state, or 1 of an element in the sesquiox- 
 ide state. The general formulas of such compounds is 
 hence RO, Si, or BO, Sis, or, if elements in both the pro- 
 toxide and sesquioxide state are present, (R; B) O, 813, as 
 explained on page 81. 
 
 In the Unisilicates, one molecule of silicon is combined 
 with two of an element in the protoxide state, that is, for 
 example, Mg,, Cas, Fes 5 or with two-thirds of a molecule in 
 the sesquioxide state, that is, two-thirds of Al, Ee, Mn. 
 The formula of these silicates is hence R, O,8i, or B% Ou 
 Si, or, in order to remove the fraction in the last, Ry Or 
 Si;; which becomes, when elements in the protoxide and 
 sesquioxide state are both present, (Rs, RB), Ow Si; 
 
 Among the species referred to the Unisilicates there are 
 some that vary from the unisilicate ratio. This occurs 
 especially in species in which an alkali is present, as in the 
 feldspars, micas, and scapolites. 
 
 The Subsilicates vary in the proportion of the silicon to 
 the basic elements, and graduate into the unisilicates. 
 
BISILICATES. 243 
 
 The same three grand divisions exist more or less satis- 
 factorily among the hydrous silicates. 
 
 A. ANHYDROUS SILICATES. 
 I. BISILICATES. 
 
 The bisilicates, when the base is in the protoxide state, 
 and hence have the general formula R O, Si, are resolved in 
 analyses into protoxides and silica in the ratio of 1RO to 
 18i O,, in which, as the term distlicate implies, the oxygen 
 of the silica is twice that of the protoxides. If the base is 
 in both the protoxide and sesquioxide states, giving the for- 
 mula R,,RO,8i;,, the mineral is resolved in analyses into 
 protoxides, sesquioxides and silica. If the ratio of the pro- 
 toxides to sesquioxides is1:1, the formula will become 
 Rh; $R O,8i;; and analyses give then, for the’ oxides and 
 silica 3RO, 1R 0,6 8i O,. 
 
 Among the following bisilicates the species from ensta- 
 tite to spodumene and amphibole make a natural group 
 called the hornblende, or hornblende and augite group. 
 They are closely related in composition and also in crystal- 
 lization. ‘The cleavage prism is rhombic, and has either an 
 angle of about 1243° or of about 87°; and the former of 
 these two rhombic prisms has just twice the breadth of the 
 other ; that is, if the lateral axis from the front to the 
 back edge in each be taken as unity, the other lateral axis 
 is twice as long in the prism of 1244° as it is in that of 87°. 
 The forms are either trimetric, monoclinic or triclinic; 
 and yet the close relations just stated exist between them. 
 Enstatite is a magnesium or magnesium and iron species 3 
 wollastonite, a calcium species; rhodonite, a manganese 
 species ; pyroxene and hornblende contain calcium with 
 magnesium or iron; spodumene contains lithium and alu- 
 minum, aluminum replacing the elements that in other 
 species are in the protoxide state. 
 
244 DESCRIPTIONS OF MINERALS. 
 
 Enstatite. 
 
 Trimetric. IA [=88° 16’. Prismatic cleavage easy. 
 Usually possesses a fibrous appearance on the cleavage sur- 
 face. Also massive and lamellar. 
 
 Color, grayish, yellowish or greenish-white, or brown. 
 Lustre pearly ; often metalloidal in the bronzite variety. 
 H. 5°5. G. 3:1-3°3. 
 
 Composition. Mg 0; S8i=Silica 60, magnesia 40. B.B. in- 
 fusible, and insoluble. Bronzite has a portion of the mag- 
 nesium replaced by iron. 
 
 Diff. Resembles amphibole and pyroxene, but is infusi- 
 ble, and trimetric in crystallization. 
 
 Obs. Occurs in the Vosges ; Moravia; Bavaria ; Baste, 
 in the Hartz; Leiperville and Texas, Pa. ; Brewster’s, N. Y. 
 
 Hypersthene is very near bronzite in crystalline form and in com- 
 position. It contains a larger percentage of iron, and on being heated 
 
 B.B. on charcoal it becomes magnetic. Occurs at St. Paul’s Island, in 
 Labrador; Isle of Skye; in Greenland ; Norway, etc. 
 
 Wollastonite.—Tabular Spar. 
 
 Monoclinic. Rarely in oblique flattened prisms. Usually 
 massive, cleaving easily in one direction, and showing a 
 lined or indistinctly columnar surface, with a vitreous Justre 
 inclining to pearly. 
 
 Usually white, but sometimes tinged with yellow, red or 
 brown. Translucent, or rarely subtransparent. Brittle. 
 H.=4°5-5. G.=2°75-2°9. 
 
 Composition. CaO, Si=Silica 52, lime 48=100. B.B. 
 fuses with difficulty to a subtransparent, colorless glass; in 
 powder decomposed by hydrochloric acid, and the solution 
 gelatinizes on evaporation ; often effervesces when treated 
 with acid on account of the presence of calcite. 
 
 Diff. Differs from asbestus and tremolite in its more viter- 
 ous appearance and fracture, and by its gelatinizing in acid; 
 from the zeolites by the absence of water, which all zeolites 
 give in a closed tube ; from feldspar in the fibrous appear- 
 ance of a cleavage surface and the action of acids. 
 
 Obs. Usually found in granite or granular limestone ; 
 occasionally in basalt or lava, Occurs in Ireland at Dun- 
 more Head; at Vesuvius and Capo di Bove; in the Hartz ; 
 Hungary ; Sweden; Finland ; Norway. 
 
 At Willsboro’, Lewis, Diana, and Roger’s Rock, N. Y., 
 
BISILICATES. 245 
 
 of a white color, along with garnet ; at Boonville, in bowl- 
 ders with garnet and pyroxene ; Grenville, Lower Canada ; 
 in Bucks County, Pennsylvania ; at Keweenaw Point, Lake 
 Superior. delforsite is impure wollastonite. 
 
 Pyroxene.—Augite. 
 
 Monoclinic. 7A J=87° 5’; cleavage perfect parallel with 
 the sides of this prism, and also distinct parallel with the 
 
 ee 3. 
 
 Alay Vislay 
 ff 
 7 
 
 diagonals. Usually in thick and stout prisms, of 4, 6 or 8 
 sides, terminating in two faces meeting at an edge. JAi-t 
 133° 33', J A 1-i=136° 27’; 1 A 1=120° 32’. Massive varie- 
 ties of a coarse lamellar structure ; also fibrous, fibres often 
 very fine and often long capillary. Also granular, usually 
 in coarse granular and friable masses ; grains usually angu- 
 lar ; sometimes round ; also compact massive. 
 
 Colors green of various shades, verging to white on one 
 side and brown and black on the other, passing through 
 blue shades, but not yellow. Lustre vitreous, inclining to 
 resinous or pearly ; the latter especially in fibrous varieties. 
 Transparent to opaque. H.=5-6. G.=3°2—-3°9. 
 
 Composition. RO,Si; in which R may be Ca, Mg, Fe, 
 Mn, and sometimes Zn, K,, Na, these bases replacing one 
 another without changing the crystalline form, of which 
 two or more are usually present ; the first three are most 
 common. Calcium is always present. The following is an 
 analysis of a typical variety : Silica 55:0, lime 23°5, magne- 
 sia 16°5, manganese protoxide *5, iron protoxide 4°5=100. 
 Fuses B.B., but its fusibility varies with the composition, 
 and the ferriferous varieties are most fusible. Insoluble in 
 acids. 
 
 Diff. Its crystalline form, and its ready cleavage in two 
 planes nearly at right angles to one another, are the best 
 
 characters for its determination. 
 VARIETIES.—The varieties may be divided into three sec- 
 
 
 
246 DESCRIPTIONS OF MINERALS. 
 
 tions—the light colored, the dark colored, and the thin 
 foliated. 
 
 L Malacolite or white augite is a calcium magnesium 
 pyroxene, and includes white or grayish-white crystals or crys- 
 talline masses. Duiopside, of the same composition, occurs in 
 greenish-white or grayish-green crystals, and cleavable masses 
 cleaving with a bright smooth surface. Sahlite contains 
 iron in addition, and is of a more dingy green color, has less 
 lustre and coarser structure than diopside, but is otherwise 
 similar; named from the place Sahla, where it occurs. 
 Fassaite contains a little alumina in addition to the ele- 
 ments of sablite, and is found in crystals of rich green shades 
 and smooth and lustrous exterior. The name is derived 
 from the foreign locality Fassa. Ooccolite is a general name 
 for granular varieties, derived from the Greek coccos, grain. 
 The green is called green coccolite, the white, white coccolite. 
 The specific gravity of these varieties varies from 3°25 to 3:3. 
 
 Asbestus. This name includes fibrous varieties of both 
 pyroxene and hornblende ; it is more particularly noticed 
 under the latter species, as pyroxene is rarely asbestiform. 
 
 Il. Awgite includes the black and greenish-black crystals, 
 which contain a larger percentage of iron, or iron and mag- 
 nesium, and which mostly present the form in figure 1. Spe- 
 cific gravity 3:°3-3°4. This is the common pyroxene of erup- 
 tive rocks. Hedenbergite, an iron-calcium pyroxene, is a green- 
 ish-black opaque variety, in cleavable masses affording a 
 ercenish-brown streak ; specific gravity 3°. Polylite, Hud- 
 sonite, and Jeffersonite, fall here ; the last contains some 
 zinc oxide. ‘I'hese varieties fuse more easily than the pre- 
 ceding, and the globule obtained is colored black by the 
 iron oxide. 
 
 III. Diallage is a thin-foliated variety, often occurring 
 imbedded in serpentine and some other rocks. It differs 
 from bronzite and hypersthene in crystalline form, and in 
 being fusible. 
 
 Obs. Pyroxene is one of the most common minerals. It 
 occurs in almost all basic eruptive rocks, like doleryte, as an 
 essential constituent, and is frequently met with in rocks of 
 other kinds ; common also in granular limestone. In basalt 
 the crystals are generally small and black or greenish black. 
 In the other rocks, they occur of all the shades of color 
 given, and of all sizes to a foot or more in length. One crys- 
 tal from Orange County, measured 6 inches in length, and 
 
BISILICATES. 247 
 
 10 in circumference. White crystals occur at Canaan, Conn., 
 Kingsbridge, New York County, and the Sing Sing quarries, 
 Westchester County, N. Y.; in Orange County at several 
 
 _localities ; green crystals at Trumbull, Conn., at various 
 places in Orange County, N. Y., Roger’s Rock and other 
 localities in Essex, Lewis, and St. Lawrence counties. Dark 
 green or black crystals are met with near Edenville, N. Y., 
 
 _ Diana, Lewis County. Jeffersonite occurs at Franklin, in 
 N.J. Green coccolite is foundat Roger’s Rock, Long Pond, 
 and Willsboro’, N. Y.; black coccolite, in the forest of Dean, 
 Orange County, N.Y. Diopside, at Raymond and Rumford, 
 Me., Hustis’s farm, Phillipstown, N. Y. 
 
 Pyroxene was thus named by Hatiy from the Greek pur, 
 fire, and xenos, stranger, in allusion to its occurring in lavas, 
 where, according to a mistake of Haiiy, it did not belong. 
 The name Augite is from the Greek auge, lustre. 
 
 Afgerite. Black to greenish black in color. It is a pyroxene con- 
 taining nearly 10 percent. of soda, and much iron sesquioxide. From 
 near Brevig in Norway ; Hot Springs, Arkansas. 
 
 Aemite. In long highly-polished prisms, of a dark-brown or reddish- 
 brown color, with a pointed extremity, penetrating granite, near Kongs- 
 berg in Norway. / A /=86° 56’, resembles pyroxene. Contains over 
 12 per cent. of soda. Fuses easily before the blowpipe. 
 
 Babingtonite. Resembles some varieties of pyroxene. It occurs in 
 greenish-black splendent crystals in quartz at Arendal in Norway. 
 
 Uralite, Has the form of pyroxene but cleavage of hornblende. 
 
 Rhodonite.—Manganese Spar, Fowlerite. 
 
 Triclinic, but very nearly isomorphous with pyroxene. 
 Usually massive, the cleavage often indistinct. 
 
 Color reddish, usually deep flesh-red ; also brownish, 
 greenish, or yellowish, when impure ; very often black on 
 the surface ; streak uncolored. Lustre vitreous. 'Transpa- 
 rent to opaque. Becomes black on exposure. H.=5'5-6°5. 
 G.=3°4-3'7. 
 
 Composition. MnO,Si= Silica 45°9, manganese protox- 
 ide 54°1=100. It usually contains a little iron and lime 
 replacing the manganese. Becomes dark brown when heat- 
 ed, and, with borax in the outer flame, gives a deep violet 
 color to the bead while hot, and a red-brown when cold. 
 
 Diff. Resembles somewhat a flesh-red feldspar, but dif- 
 fers in greater specific gravity, in blackening on long ex- 
 posure, and in the glass with borax. 
 
 Obs. Occurs in Sweden, the Hartz, Siberia, and else- 
 
248 DESCRIPTIONS OF MINERALS, 
 
 where. In the United States it is found, in masses, at 
 Plainfield and Cummington, Mass. ; also abundantly at 
 Hinsdale, and on Stony Mountain, near Winchester, N. H.; 
 at Blue Hill Bay, Me. ‘The black exterior is a more or less 
 pure hydrated oxide of manganese. 
 
 Rhodonite may be used in making a violet-colored glass, 
 and also for a colored glazing on stoneware. It receives a 
 high polish and is sometimes employed for inlaid work. 
 
 Spodumene. 
 
 Monoclinic. J A J=87, being near the angle of pyroxene. 
 Cleavage easy, parallel to Z and 7-7. Surface of cleavage 
 pearly. Color grayish or greenish. ‘Translucent to sub- 
 translucent. H.=6 5-7. G.=3:1-3°19. 
 
 Composition. (R,, Al) O,8i,, in which R is lithium and 
 equals Li., and 3 Li, is to Alas1:4. This corresponds to 
 silica 64:2, alumina 29°4, lithia 6°4=100. B.B. becomes 
 white and opaque, fuses, swells up, and imparts to the flame 
 the purple-red flame of lithia. Unaffected by acids. 
 
 Diff. Resembles somewhat feldspar and scapolite, but 
 has a higher specific gravity and a more pearly lustre, and 
 affords rhombic prisms by cleavage. Its lithia reaction is 
 its most characteristic test. 
 
 Obs. Occurs in granite at Goshen; also at Chesterfield, 
 Norwich and Sterling, Mass. ; at Windham, Me. ; at Brook- 
 field, Ct. It is found at Uton, in Sweden ; Sterzing in the 
 Tyrol; and at Killiney Bay, near Dublin. 
 
 This mineral is remarkable for the lithia it contains, and 
 has been used for obtaining this rare earth. 
 
 Petalite. 
 
 Monoclinic. Usually in imperfectly cleavable masses ; 
 most prominent cleavage angle 141° 30’. Color white or 
 gray, or with pale-reddish or greenish shades, Lustre vit- 
 reous to sub-pearly. Translucent. H.=6-6°5. G.=2°5. 
 
 Composition. Contains lithia like spodumene, and gives 
 the percentage—Silica 77°9, alumina 17°7, lithia 3:1, soda 
 1°3=100. Phosphoresces when gently heated. Fuses with 
 difficulty on the edges. Gives the reaction of lithia like 
 spodumene. 
 
 Diff, Its lithia reaction allies it to spodumene, but it 
 
BISILICATES. 249 
 
 differs from that mineral in lustre, specific gravity, and 
 greater fusibility. 
 
 Obs. From Uté, Sweden; also from Elba (Castor or Cas- 
 -torite). 
 Amphibole.—Hornblende. 
 
 Monoclinic. ZA J=124° 30’. Cleavage perfect parallel 
 with /. Often in long, slender, flat rhombic 1. 
 prisms (fig. 2), breaking easily transversely; 
 also often in 6-sided eae Sp oblique aan 
 extremities. Frequently columnar, with a ats 
 bladed structure ; long fibrous, the fibres 
 coarse or fine and often like flax, with a 
 pearly or silky lustre; also lamellar; also 3. 
 granular, either coarse or fine. 
 
 Colors from white to black, passing 
 through bluish-green, grayish-green, green, 
 and brownish-green shades, to black. Lus- 
 tre vitreous, with the cleavage face inclining to pearly. 
 Nearly transparent to opaque. H.=5-6.. G.=2°9-3°4. 
 
 Composition. RO; Si, as for pyroxene. R may corre- 
 spond to two or more of the basic elements Meg, Ca, Fe, Mn, 
 Na,, K,, the first three being most common. Aluminum 
 is very often present in amphibole, replacing a portion 
 of the silicon. The blowpipe characters are like those of 
 pyroxene. It fuses, but the fusibility varies indefinitely, 
 being easiest in the black varieties. 
 
 Diff. It is distinguished by the very ready cleavages pa- 
 rallel to a prism of 1244°, while pyroxene cleaves at nearly 
 a right angle (87° 5’). 
 
 This species, like pyroxene, has numerous varieties, dif: 
 fering much in external appearance, and arising from the 
 _ Same causes—isomorphism and crystallization. 
 
 The following are the most important varieties : 
 
 
 
 I, LIGHT-COLORED VARIETIES. 
 
 Tremolite, Grammatite. 'Tremolite comprises the white 
 and grayish crystallizations which usually occur in blades 
 or long crystals penetrating the gangue or aggregated into 
 coarse columnar forms. Sometimes nearly transparent. 
 G.=2:9. Formula (Ca, Mg) O;Si=Silica 57-70, magnesia 
 28°85, lime 13°45=100, The name is from the foreign lo- 
 cality, Tremola, in Switzerland. 
 
 Actinolite. The light-green varieties, It isamagnesium- 
 
250 DESCRIPTIONS OF MINERALS. 
 
 calcium-iron amphibole. Glassy actinolite includes the bright 
 glassy crystals, of a rich green color, usually long and slen- 
 der, and penetrating the gangue like tremolite. Radiated 
 actinolite includes olive-green masses, consisting of aggre- - 
 gations of coarse acicular fibres, radiating or divergent. 
 ‘Asbestiform actinolite resembles the radiated, but the fibres 
 are more delicate. Massive actinolite consists of angular 
 grains instead of fibres. G.=3°0-3'1. The name actino- 
 lite alludes to the radiated structure of some varieties, and 
 ss derived from the Greek, aktin, a ray of the sun. 
 
 Asbestus. In slender fibres easily separable, and some- 
 times like flax. Hither green or white. Amianthus, in- 
 cludes fine silky varieties. (Much so called is serpentine ; 
 serpentine is hydrous, and is thereby easily distinguished.) 
 Ligniform asbestus is compact and hard ; it occurs of brown- 
 ish and yellowish colors, and looks somewhat like petrified 
 wood. Mountain leather occurs in thin, tough sheets, look- 
 ing and feeling a little like kid leather ; it consists of inter- 
 laced fibres of abestus, and forms thin seams between layers 
 or in fissures of rocks. Mountain cork is similar, but is in 
 thicker masses; it has the elasticity of cork, and is usually 
 white or grayish white. 
 
 The preceding light-colored varieties contain little or no 
 alumina or iron. 
 
 Composition of glassy actinolite: Silica 59°75, magnesia 
 91'1, lime 14°25, protoxide of iron 3°9, protoxide of man- 
 ganese 0°3, hydrofluoric acid 0°8 (Bonsdorf). 
 
 Nephrite is a very tough compact variety, related to tre- 
 molite. Color light-green or blue. It breaks with a splin- 
 tery fracture and glistening lustre. H.—6-6'5. G.=3. It is 
 a magnesium-calcium amphibole. Nephrite is made into i1m- 
 ages, and was formerly worn as a charm. It was supposed to 
 be a cure for diseases of the kidney, whence the name, from 
 the Greek, nephros, kidney. In New Zealand, China and 
 Western America, it is carved by the inhabitants, or pol- 
 
 lished down into various fanciful shapes. It is called jade; 
 - but the aluminum-sodium silicate, called jadeite, is the stone 
 most highly prized of all those that are called jade. Much 
 of the mineral from China called jade is prehnite. 
 
 II. DARK-COLORED VARIETIES, 
 
 Cummingtonite is a magnesium-iron amphibole. Color 
 gray or brown ; usually fibrous. Named from the locality 
 where found, Cummington, Mass. 
 
BISILICATES, 251 
 
 Pargasite. Dark-green crystals, short and stout (resem- 
 bling fig. 4), with bright lustre, of which Pargas in Finland 
 is a noted locality. G.=3:11. 
 
 Composition. Silica 45°5, alumina 14:9, iron protoxide 
 8:8, manganese protoxide 1°5, magnesia 14:4, lime 14:9= 
 100. 
 Hornblende. Black and greenish-black crystals and mas- 
 sive specimens. Often in slender crystallizations like actino- 
 lite ; also short and stout like figs. 4 and 5, the latter more 
 especially. It contains a large percentage of iron oxide, and 
 to this owes its dark color. It is a tough mineral, as is im- 
 plied in the name it bears. This character, however, is best 
 seen in the massive specimens. Pargasite and hornblende 
 contain both alumina and iron. 
 
 Composition of a hornblende: Silica 48°8, alumina 175, 
 magnesia 13°6, lime 10°2, iron protoxide 18°8, manganese 
 protoxide 1:1=100. 
 
 Obs. Hornblende is an essential constituent of certain 
 rocks, as syenyte, dioryte and hornblende schist. Actino- 
 lite is usually found in magnesian rocks, as tale, steatite or 
 serpentine ; tremolite in granular limestone and dolomite ; 
 asbestus in the above rocks and also in serpentine. Black 
 crystals of hornblende occur at Franconia, N. H., Chester, 
 Mass., Thomastown, Me., Willsboro’, N. Y., in Orange 
 County, N. Y., and elsewhere. Pargasite occurs at Phipps- 
 burg and Parsonsfield, Me.; glassy actinolite, in steatite 
 or talc, at Windham, Readsboro’, and New Fane, Vt., 
 Middlefield and Blandford, Mass.; and radiated varieties 
 at the same localities and many others. ‘Tremolite and 
 gray hornblende occur at Canaan, Ct., Lee, Newburgh, 
 Mass., in Thomaston and Raymond, Me., Dover, Kings- 
 bridge, and in St. Lawrence County, N. Y.; at Chestnut 
 Hill, Penn. ; at the Bare Hills, Md. Asbestus at many of 
 the above localities; also Brighton and Sheffield, Mass. ; 
 Cotton Rock and Hustis’s farm, Phillipstown, N. Y., near 
 the Quarantine, Richmond County, N. Y. Mountain lea- 
 ther is met with at Brunswick, N.J. denite, a white 
 aluminous kind, occurs at Edenville, N. Y. 
 
 Asbestus is the only variety of this species of any use in 
 the arts. The flax-hke variety is sometimes woven into 
 fire-proof textures. Its incombustibility and slow conduc- 
 tion of heat render it a complete protection against the 
 flames. It is often made into gloves. A fabric when 
 
252 DESCRIPTIONS OF MINERALS. 
 
 dirty, need only be thrown into the fire for a few minutes 
 to be white again. ‘The ancients, who were acquainted with 
 its properties, are said to have used it for napkins, on ac- 
 count of the ease with which it was cleaned. It was also 
 the wick of the lamps in the ancient temples ; and because 
 it maintained a perpetual flame without being consumed, 
 they named it asbestos, unconsumed. It is now used for 
 the same purpose by the natives of Greenland. The name 
 amianthus alludes to the ease of cleaning it, and ib is de- 
 rived from amiantos, undefiled. Asbestus 1s extensively 
 used for lining iron safes, and for protecting steam pipes 
 and boilers. ‘I'he best locality for collecting asbestus in the 
 United States is that near the Quarantine, in Richmond 
 County, N. Y. 
 
 Anthophyllite is related in the angle of its prism to hornblende, but 
 is trimetric. In composition and its infusibility before the blowpipe, 
 it ig near bronzite. B.B. it becomes magnetic. From Kongsberg in 
 Norway, and near Modum. Kupfferite has the hornblende angle, but 
 in composition it is like enstatite, being a magnesium silicate. 
 
 Arfvedsonite. Near hornblende; but contains over 10 per cent. 
 of soda, like acmite. . 
 
 Crocidolite. Near arfvedsonite in composition. A lavender-blue or 
 leek-green fibrous mineral from Orange River, South Africa, and from 
 the Vosges ; also from Rhode Island (A. H. Chester). 
 
 Gastadite. A dark blue to azure-blue mineral related to amphibole, 
 from the valleys of Aosta and Locano. 
 
 Glaucophane. A bluish mineral with the amphibole angle, from the 
 Island of Syra. Wichtisite may be the same mineral. 
 
 Milarite. Trimetric, of the composition (KH)Ca, Al 0,, Si,,; the 
 quantivalent ratio for bases and silica 1:4; being therefore a quater- 
 silicate instead of a bisilicate. 
 
 Beryl.—Emerald. 
 
 Hexagonal. In hexagonal prisms, usually without regular 
 terminations. Cleavage basal, not very distinct. 
 Rarely massive. 
 
 Color green, passing into blue and yellow ; 
 color rather pale, excepting the deep and rich 
 green of the emerald. Streak uncolored. Lus- 
 tre vitreous ; sometimes resinous. Transparent 
 to subtranslucent. Brittle. H.= 75-8. G.= 
 2°65-2°75. 
 
 Vanrreties. The emerald is the rich green variety ; 1t owes 
 its color to the presence of chromium, Beryl includes the 
 paler varieties, which are colored by oxide of iron, Aqua- 
 
 
 
BISILICATES, 203 
 
 marine includes clear beryls of a sea-green, or pale-bluish or 
 bluish-green tint. 
 
 Composition. Be,Al0O,;S8i;=Silica 66°8, alumina 19°1, 
 glucina 14°1=100. Hmerald contains less than one per 
 cent. of chromium oxide. B.B. becomes clouded, but does 
 not fuse ; at a very high temperature the edges are rounded. 
 Unacted upon by acids. , 
 
 Diff. The hardness distinguishes this species from apa- 
 tite; and this character, and also the form of the crystals, 
 from green tourmaline. 
 
 Obs. The finest emeralds come from Muso, near Santa Fé 
 in New Grenada, where they occur in dolomite. A crystal 
 from this locality, 24 inches long and about 2 inches in 
 diameter, is in the cabinet of the Duke of Devonshire ; it 
 weighs 8 oz. 18 dwts., and is a regular hexagonal prism. A 
 more splendid specimen, but weighing only 6 oz., in the 
 possession of Mr. Hope, of London, cost £500. Emer- 
 alds of less beauty, but of gigantic size, occur in Siberia. 
 One specimen in the royal collection of Russia measures 43 
 inches in length and 12 in breadth, and weighs 163 pounds 
 troy. Another is 7 inches long and 4 broad, and weighs 6 
 pounds. Mount Zalorain Upper Egypt affords a less dis- 
 tinct variety. 
 
 The finest beryls (agwamarines) come from Siberia, Hin- 
 dostan and Brazil. One specimen belonging to Dom Pedro 
 is as large as the head of a calf, and weighs 225 ounces, or 
 more than 184 pounds troy ; it is transparent and without a 
 flaw. In 1827 a fine aquamarine, weighing 35 grams, was 
 found in Siberia, which is said to have been valued at 
 600,000 francs. 
 
 In the United States, beryls of enormous size have been 
 obtained, but seldom transparent crystals. They occur in 
 granite or gneiss. One hexagonal prism from Grafton, N. 
 H., weighs 2,900 pounds and measured 4 feet in length, with 
 one diameter of 82 inches and another of 22; its color was 
 bluish green, excepting a part at one extremity, which was 
 dull green and yellow. At Royalston, Mass., one crystal has 
 been obtained a foot long, and pellucid crystals are some- 
 times met with. Haddam, Conn., has afforded fine crys- 
 tals (see the figure). Other localities are Barre, Fitchburg, 
 Goshen, Mass.; Albany, Norwich, Bowdoinham and_'Top- 
 ham, Me.; Wilmot, N. H.; Monroe, Portland, Haddam, 
 Conn.; Leiperville, Penn. 
 
Q54 DESCRIPTIONS OF MINERALS. 
 
 Phenacite. A beryllium-silicate, rhombohedral in crys- 
 tallization. From the Urals, and Durango in Mexico. 
 
 Eudialyte. A pale rose-red mineral, from West Greenland, occurring 
 in rhombohedral crystals, and containing 15°6 per cent. of zirconia, 
 Eucolite is a related species from Norway, 
 
 Pollucite. An isometric cesium silicate, white, vitreous in lustre, 
 with G@.=2'868. Analysis afforded Rammelsberg Silica 48°15, alumina 
 16°31, potash 0°47, soda 2°48, cesium oxide 30-00, water 2°59=100, 
 giving very nearly the bisilicate formula H,Cs,Al0,, Si,, From Elba. 
 
 II. UNISILICATES. 
 
 For the convenience of the student, the general formulas 
 of the regular Unisilicates are here re-stated. They are as 
 follows : 
 
 If the base is in the protoxide state alone, the formula is 
 R, 0,Si, in which R stands for Ca, Mg, Fe, Mn, Ka, Nay, Or 
 Li,, or other mutually replaceable base. In analyses, the 
 mineral is resolved into protoxides and silica, in the ratio 
 of 2 RO to SiO,, in which the oxygen of the silica equals 
 that of the basic portion. 
 
 If the base is in the sesquioxide state alone, the formula 
 is RB, 0. Si,, in which R may stand for Al, Fe, or Mn, etc. 
 Here the mineral is resolved, in analyses, into sesquioxides 
 and silica in the ratio of 2R 0, to 388i O,, in which the oxy- 
 gen of the silica again equals that of the basic portion. 
 
 If the basic portion is partly in the protoxide state and 
 partly in the sesquioxide, the formula, in its most general 
 form, is (R,, B),OwSi, In this formula the ratio of R, to 
 R is not stated. If the ratio is 1:1, the formula becomes 
 R,B 0, Si,, or its equivalent ($Rs $R)2 Ow Sis In a case like 
 this last, the mineral is resolved, in analyses, into protoxides, 
 sesquioxides and silica, in the ratio of 3RO:R0;:3810,, 
 in which again the oxygen of the bases equals that of the 
 silica. 
 
 If the proportion of R, toR is 1:3, this corresponds to 
 4R,: R, or, its equivalent, R: R; and hence the formula in 
 its general form will be RR O, Sis. 
 
UNISILICATES, . 255 
 
 Tf the base is in the dioxide state, the formula becomes 
 RO,Si, an example of which occurs in zircon, whose for- 
 mula is Zr O, 81. 
 
 There are several natural groups of species among the , 
 Unisilicates. 
 
 GROUP. STATE OF BASES. CRYSTALLIZATION. 
 
 1. Chrysolite group, __ protoxide, Trimetric. 
 2. Willemite group, protoxide, Hexagonal, 
 3. Garnet group, protoxide and? jy. metric 
 sesquioxide, ; 
 4, Zircon group, dioxide, Dimetric. 
 5. Idocrase and Sca- protox. and ses- : : 
 polite groups, quiox. t DUnewric. 
 : Trimetric; plane angle 
 6. Mica group, protox. and ses- of hase 190%. micas 
 Nom 9 ceous. 
 7, Feldspar group, protox. and ses-) Monoclinic or triclinic, 
 quiox. INI nearly 120°. 
 
 In the Scapolite, Mica and Feldspar groups part of the 
 species contain an alkaline metal in the basic portion, and 
 such kinds have generally an excess of silica. Among the 
 feldspars, the species containing only calcium as the protox- 
 ide base, is a true Unisilicate. In the others, there is an 
 excess directly proportional to the increase of the soda, as _ 
 explained beyond. 
 
 Chrysolite.—Olivine. 
 
 Trimetric. In rectangular prisms having cleavage par- 
 allel with 7-¢. Usually in imbedded grains of an olive- 
 green color, looking like green bottle-glass. Also yellow- 
 ish green. ‘Transparent to translucent. H.=6-7. G.=3°3 
 -3°5. Looks much like glass in the fracture, except in its 
 having cleavage. 
 
 Composition. (Mg, Fe),O0,Si=, for a common variety, 
 Silica 41°39, magnesia 50°90, iron protoxide 7°71=100. 
 The amount of iron is variable. B.bB. whitens but is in- 
 fusible. With borax forms a yellow bead owing to the iron 
 present. Decomposed by hydrochloric acid, and the solu- 
 tion gelatinizes when evaporated. Hyalosiderite is a very 
 ferruginous variety which fuses B.B. 
 
 Diff. Distinguished from green quartz by its occurring 
 
256 DESCRIPTIONS OF MINERALS. 
 
 disseminated in basaltic rocks, which never so occurs; and 
 in its cleavage. From obsidian or volcanic glass it differs 
 in its infusibility. 
 
 Obs. Occurs ‘as a rock formation; also disseminated 
 through basalt and other eruptive rocks, and is a charac- 
 teristic mineral of some varieties of them.—Has been 
 found in New Hampshire, Canada, and elsewhere. As a 
 rock it occurs in North Carolina, and Pennsylvania. It 
 also occurs in many meteorites. Boltonite, from limestone 
 at Bolton, Mass., is a variety of chrysolite. 
 
 Sometimes used as a gem, but it is too soft to be valued, 
 and is not delicate in its shade of color. 
 
 Forsterite is a magnesian chrysolite Mg20.S8i; Payalite, an iron 
 chrysolite, Fe,O,S8i ; Monticellite, a calcium-magnesium, Ca Mg, O, Si; 
 Hortonolite, an iron-magnesium chrysolite from Orange County, N. Y.; 
 Repperite, an iron-manganese-zince chrysolite from Stirling Hill, N.J.; 
 Tephroite, a manganese chrysolite Mn, O, Si, from Stirling Hill, N. J. ; 
 Knebelite, a manganese-iron chrysolite, MnFe 0, Si, from Dannemora, 
 Sweden. 
 
 Leucophanite and meliphanite are species containing the element 
 glucinum (beryllium), the former greenish yellow and G=2'97, the 
 latter yellow and G=3°018. From Norway. 
 
 Wéhlerite contains zirconium, and also columbium ; color light yel- 
 low. G=8-41. 
 
 Willemite is a zinc unisilicate, Zn,O,Si. See page 157. 
 
 Dioptase is a copper silicate, which, making the water basic, is 2 
 unisilicate, H,CuO,Si. See page 141. . 
 
 Fricdelite is a rose-red manganese silicate of the general formula 
 R, O, hie which R consists of manganese and hydrogen in the atomic 
 ratio 2:1. 
 
 Helvite (Helvin). Isometric ; in tetrahedral crystals. Color honey- 
 yellow, brownish, greenish. Lustre vitreo- resinous. H.=—6-6'6. 
 G.—3°1-3:3. Contains manganese, iron, and glucinum, and some 
 sulphur. From Saxony, and Norway. 
 
 Danalite. Isometric; in octahedral crystals. Color flesh-red to 
 gray. Lustre vitreo-resinous. H.=5°5. G.=3'427. Contains zinc, 
 clucinum, iron, manganese. Found disseminated through the granite 
 at Rockport, Cape Ann, Mass., and alSo near Gloucester, Mass. 
 
 Eulytite is a bismuth silicate, and Bismutoferrite a bismuth-and- 
 iron silicate. 
 
 Garnet. 
 
 Isometric. Common in dodecahedrons (fig. 1), also in 
 trapezohedrons (fig. 2), and both forms are sometimes vari- 
 ously modified. Cleavage parallel to the faces of the dode- 
 cahedron ; sometimes rather distinct, Also found massive 
 granular, and coarse lamellar. ; 
 
UNISILICATES. O57 
 
 Color deep red to cinnamon color; also brown, black, 
 green, emerald-green, white. Transparent to opaque. Lus- 
 tre vitreous. Brittle. H.=6°5-7°5. G.=3-1-4:3. 
 
 i. 2. 
 
 WA 
 
 Composition and Varieties. The general formula for the 
 species is (R,R), O,Sis;; in which R may be calcium, mag- 
 nesium, iron, manganese, and R, may be aluminum, iron, 
 chromium. ‘The varieties owe their differences to the pro- - 
 portions of these elements, or the substitution of one for 
 another. Most garnets fuse easily to a brown or black glass ; 
 but the fusibility varies with the constituents, and chrome- 
 garnet is infusible. They are not decomposed by hydro- 
 chloric acid ; but if first ignited, then pulverized and treated 
 with acid, they are decomposed, and the solution usually 
 gelatinizes when evaporated. 
 
 There are three series among the varieties: one, that of 
 alumina-garnet, in which the sesquioxide base is chiefly 
 aluminum ; the second, that of iron-garnet, in which the 
 sesquioxide base is chiefly iron instead of aluminum ; and 
 third, chrome-garnet, in which it is chromium. 
 
 I. ALUMINA-GARNET. 
 
 Almandite (Almandine). An iron alumina-garnet, Fe, 
 Al O,.8i;=Silica 36:1, alumina 20°6, iron protoxide 43:3= 
 100. It occurs of various shades of red from. ruby-red and 
 hyacinth-red, to columbine-red and brownish red. When 
 transparent it is called precious garnet; and, if not so, 
 ~ common garnet. 
 
 Grossularite (including Cinnamon Stone). <A lime alu- 
 mina-garnet, Ca;AlO,,.Si;—Silica 40°1, alumina 22°%, lime 
 37°2—100, but often with some iron protoxide in place of 
 part of the lime. The name Grossularite was given to a 
 pale-green garnet, in allusion to the color, from the Latin 
 name for gooseberry. Cinnamon Stone includes the cinna- 
 mon-colored variety. - 
 
 
 
 17 
 
258 DESCRIPTIONS OF MINERALS. 
 
 Pyrope. A magnesia alumina-garnet Mg,Al Or Si, Color 
 deep red, but varying to black and green. 
 
 Spessartite. A manganese alumina-garnet (Mn, Fe),Al 
 O, Sis, some iron replacing part of the manganese. Color 
 red, brownish red, hyacinth-red. A Haddam specimen af- 
 forded Seybert, Silica 35-8, alumina, 18-1, iron protoxide 
 14:9, manganese protoxide 31:0. 
 
 TI. IronN-GARNET. 
 
 Andradiie. A lime iron-garnet, Ca,Fe 0,.Si; Colors 
 various, from that of almandite or common garnet, to a 
 wine-yellow, as in Topazolite ; green, as in Jelletite ; and 
 black, asin Melanite and Pyreneite. 
 
 Colophonite is a dark-red to brownish-yellow coarse gran- 
 ular garnet having often iridescent hues. 
 
 Aplome is a red variety. Rothofite has manganese in place 
 of part of the lime, and a yellowish-brown to reddish-brown 
 color. 
 
 Viter-garnet contains yttria in place of part of the lime. 
 
 Bredbergite. A lime-magnesia iron-garnet. 
 
 III. CHRoME-GARNET. 
 
 Ouvarovite. An emerald-green lime chrome-garnet (Ca, 
 Mg); He Op Sis. G.=3°41-3°42. 
 
 Diff. The vitreous lustre of fractured garnet, and its 
 usual dodecahedral forms, are easy characters for distin- 
 guishing it. 
 
 Obs. Garnet occurs abundantly in mica schist, horn- 
 blende schist, and gneiss, and somewhat less frequently in 
 granite and granular limestone; sometimes in serpentine; 
 occasionally in trap, and other igneous rocks. 
 
 The best precious garnets are from. Ceylon and Green- 
 land ; cinnamon stone comes from Ceylon and Sweden ; 
 grossularite occurs ‘nthe Wilui River, Siberia, and at Tel- 
 jemarken in Norway; green garnets are found at Schwartz- 
 enberg, Saxony ; melanite, in the Vesuvian lavas ; owvaro- 
 vite, at Bissersk in Russia ; topazolite, at Mussa, Piedmont. 
 
 In the United States, precious garnets, of small size, oc- 
 cur at Hanover, N. H.; and a clear and deep red variety, 
 sometimes called pyrope, comes from Green’s Creek, Dela- 
 ware County, Penn. Dodecahedrons, of a dark red color, 
 occur at Haverhill and Springfield, N. H., some 14 inches 
 through; also at New Fane, Vt., still larger; at Unity, 
 Brunswick, Streaked Mountain, and elsewhere, Maine ; at 
 Monroe, Lyme and Redding, Conn.; Bedford, Chesterfield, 
 
UNISILICATES, 259 
 
 Barre, Brookfield, and Brimfield, Mass.; Dover, Dutchess 
 County, Roger’s Rock, Crown Point, Essex County, N. Y.; 
 Franklin, N. J. Cinnamon-colored crystals occur at Carlisle, 
 Mass., transparent, and also at Boxborough; with ido- 
 erase at Parsonsfield, Phippsburg and Rumford, Me. ; at 
 Amherst, N. H.; at Amity, N. Y., and Franklin, N. J.; 
 at Dixon’s Quarry, seven miles from Wilmington, Del. in 
 fine trapezohedral crystals. Melanite is found at Franklin, 
 N. J.. and Germantown, Penn. Chrome garnet is found 
 in Orford, Canada. Colophonite is abundant at Willsbor- 
 ough and Lewis, Essex County, N. Y.: it occurs also at 
 North Madison, Conn. 
 
 The garnet is the carbuncle of the ancients. The ala- 
 bandic carbuncles of Pliny were so called because cut and 
 polished at Alabanda, and hence the name Almandine now 
 inuse. ‘The garnet is also supposed to have been the hya- 
 cinth of the ancients. 
 
 The clear deep-red garnets make a rich gem, and are 
 much used. Those of Pegu are most highly valued. They 
 are cut quite thin, on account of their depth of color. The 
 cinnamon stone is also employed for the same purpose. 
 Pulverized garnet is sometimes employed as a substitute 
 for emery. 
 
 Pliny describes vessels, of the capacity of a pint, formed 
 from large carbuncles, ‘‘devoid of lustre and transpa- 
 rency, and of a dingy color,” which probably were large 
 garnets. 
 
 Zircon. 
 
 Dimetric. JA J=132°10'; 1A1=123°19’. Cleavage parallel 
 to J, but imperfect. Usually in crystals ; but also granular. 
 
 
 
 Color brownish red, brown, and red, of clear tints; also 
 yellow, gray, and white. Streak uncolored. Lustre more 
 or less adamantine. Often transparent ; also nearly opaque. 
 Fracture conchoidal, briliant. H.=7°5. G.=4:0-48. 
 
260 DESCRIPTIONS OF MINERALS: 
 
 Composition. Zr O,Si=Silica 33, zirconia 67=100. B.B. 
 infusible, but loses color. 
 
 Varreriss. Transparent red specimens are called hya- 
 cinth. A colorless variety from Ceylon, having a smoky 
 tinge, is called jargon ; i+ ig sold for inferior diamonds, 
 which it resembles, though much less hard. The name 
 zirconite is sometimes applied to crystals of gray or brown- 
 ish tints. 
 
 Diff. Zircon is readily distinguished from species Which 
 it resembles in other properties by its square prismatic 
 form, specific gravity, and adamantine lustre. 
 
 Obs. The zircon is confined to crystalline rocks, occurring 
 in granite, gneiss, granular limestone, and some igneous 
 rocks. Zircon-syenyte is asyenyte with disseminated zircons. 
 Zircon often occurs in auriferous sands. Hyacinth occurs 
 mostly in grains in such sands, and comes from Ceylon, 
 Auvergne, Bohemia, and elsewhere in Europe. Siberia 
 affords crystals as large as walnuts. Splendid specimens 
 come from Greenland. 
 
 In the United States, fine crystals of zircon occur in Bun- 
 combe County, N. C.; ofa cinnamon-red color in Moriah, 
 Essex County, N. Y. ; also at Two Ponds and elsewhere, 
 Orange County, In crystals sometimes an inch and a half 
 long; in Hammond, St. Lawrence County, and Johnsbury, 
 Warren County, N. Y.; at Franklin, N. J. ; in Litchfield, 
 Me.; Middlebury, Vt. ; in Canada, at Grenville, etc. 
 
 The name hyacinth is from the Greek huakinthos. But 
 it ig doubtful whether it was applied by the ancients to 
 stones of the zircon species. : 
 
 The clear crystals (hyacinths) are of common use In 
 jewelry. When heated in a crucible with lime, they lose 
 their color, and resemble a pale straw-yellow diamond, for 
 which they are substituted. Zircon is also used in jeweling 
 watches. The hyacinth of commerce is to a great extent 
 cinnamon stone, a variety of garnet. ‘The earth zirconia 
 is used as an advantageous substitute for lime in the oxyhy- 
 drogen lantern. 
 
 Auerbachite, Malacon, Tachyaphaltite, Cirstedite, Bragite, are 
 names of zircon-like minerals supposed to be zircon partly altered. 
 
 The earth zirconia is also found in the rare minerals eudialyte and 
 wohlerite ; also in polymignite, aschynite ; also sparingly in fergu- 
 
 sonite. ; 
 
UNISILICATES. 261 
 
 Vesuvianite.—-Idocrase. 
 
 even + 1— 142° 46°; 1 AL=129° 21", 1 27-1 =127° 
 14’. Cleavage not very distinct parallel with £ Also found 
 massive granular, and subcolumnar. 
 
 
 
 Color brown; sometimes passing into green. In some 
 varieties the color is oil-green in the direction of the axis 
 and yellowish green at right angles with it. Streak un- 
 colored. Lustre vitreous. Subtransparent to nearly opaque. 
 H.=65. G.=3:'33-3°4. | 
 
 Composition. (4Ca,#Al),0,,S8i; A small part of the 
 Ca is usually replaced by magnesium, and part of the alu- 
 minum sometimes by iron in the sesquioxide state. Per- 
 centage of a common variety, Silica 37:3, alumina 16-1, 
 iron sesquioxide 3°7, lime 35-4, magnesia 2-1, iron protox- 
 ide 2:9, water 2°1—99°6. B.B. fuses easily with efferves- 
 cence to a greenish or brownish globule. 
 
 Diff. Resembles some brown varieties of garnet, tourma- 
 line and epidote, but besides its difference of crystallization, 
 it is much more fusible. 
 
 Obs. Vesuvianite was first found in the lavas of Vesuvius, 
 and hence the name. It has since been obtained in Pied- 
 mont; near Christiania, Norway; in Siberia; also in the 
 Fassa Valley. Cyprine includes blue crystals from ‘Telle- 
 marken, Norway; supposed to be colored by copper. 
 
 In the United States, it occurs in fine crystals at _ 
 Phippsburg and Rumford, Sandford, Parsonsfield and 
 Poland, Me. ; Newton, N. J.; Amity, N. Y. In Canada at 
 Calumet Falls, and at Grenville. 
 
 The name idocrase is from the Greek eido, to see, and 
 krasis, mixture ; because its crystalline forms have much 
 resemblance to those of other species. 
 
 This mineral is sometimes cut as a gem for rings. 
 
 Mellilite in honey-yellow crystals (which includes Hum- 
 
262 DESCRIPTIONS OF MINERALS. 
 
 boldtilite) is a related dimetric species, from Capo di Bove, 
 near Rome, and Mount Somma, Vesuvius. 
 
 Epidote. 
 
 Monoclinic. ¢-¢A1 ¢=118° 24) (1A — 1 or 
 —1=109° 35’. Cleavage parallel to 
 
 PT pe i-i; less distinct parallel to 1-0. 
 
 Also massive granular and forming — 
 4 rock masses; sometimes columnar 
 or fibrous. 
 
 Color yellowish green (pistachio- 
 green) and ash-gray or hair-brown. Streak uncolored. 
 Translucent to opaque. Lustre vitreous, a little pearly 
 on i-i; often brilliant on the faces of crystals. Brittle. H. 
 —6-%. G.=3'25-3°D. 
 
 Composition. A lime iron-alumina silicate, the iron being 
 mostly in the sesquioxide state and replacing aluminum. 
 Percentage of common variety, Silica 37°83, alumina 22°63, 
 iron sesquioxide 15:02, iron protoxide 0°93, lime 28°27, 
 water 2°05=100°73. 
 
 B.B. epidote fuses with effervescence to a black glass 
 which usually is magnetic. Partially decomposed by hy- 
 drochloric acid, but if first ignited, is then decomposed, 
 and the solution gelatinizes on evaporation. 
 
 Green epidote is often called Pistacite. Ptedmontite is 
 a variety containing much manganese, of reddish-brown or 
 reddish-black color. 
 
 Bucklandite is an iron-epidote. 
 
 Diff. The peculiar yellowish-green color of ordinary epi- 
 dote distinguishes it at once. From zoisite and vesuvian- 
 ite it differs in fusing to a black magnetic globule. 
 
 Obs. Occurs in crystalline rocks, especially in hornblen- 
 dic rocks. It often occurs in the cavities of amygdaloidal 
 rocks. Splendid crystals, six inches long, and with bril- 
 liant faces and rich color, have been obtained at Haddam, 
 Ct: Crystallized specimens are also found at Franconia, 
 N. H., Hadlyme, Chester, Newbury and Athol, Mass.; 
 near Unity, Amity, and Monroe, N. Y.; Franklin and 
 Warwick, N. J.; Pennsylvania, at BE. Bradford ; Michigan, 
 in the Lake Superior region ; Canada, at St. Joseph. 
 
 The name epidote was derived by Haiiy from the Greek 
 epididomt, to increase, in allusion to the fact that the base 
 of the primary is frequently much enlarged in the crystals. 
 
UNISILICATES. 265 
 
 Zoisite. A mineral of the epidote group, occurring in trimetric crys- 
 tals, with JA J=116° 40’, and having a white, pale-grayish, pale- 
 greenish to reddish color ; also massive. H.=6-6°5. G.=3-'1-3°4. 
 
 It is a lime-epidote, with little or no iron. B.B. swells up and 
 fuses to a white blebby glass ; after ignition, gelatinizes with hydro- 
 chloric acid. Thulite is a rose-red variety. Occurs at Saualpe in Carin- 
 thia, in the Tyrol; Arendal, etc.; in Vermont at Willsboro’ and Mont- 
 pelier ; in Massachusetts, at Goshen, Chesterfield, etc.; in Pennsyl- 
 vania at Unionville, and in Tennessee at the Ducktown copper mine. 
 
 Saussurite, from the euphotide of the Alps in the vicinity of Lake 
 Geneva, approaches zoisite in composition, it affording Hunt Silica 
 43-59, alumina 27°72, iron sequioxide 2°61, magnesia 2°98, lime 19°71, 
 water 0-35, soda 3°08=100-04. Color whitish, greenish gray, ash-gray ; — 
 G.=3 226-3°385. H.—6°5-7. The saussurite of Orezza gave nearly the 
 same composition in an analysis by Boulanger, and that of Schwartz- 
 wald in general the same, with more of magnesia and less of lime, in 
 an analysis by Hiitlin. The high specific gravity separates it from 
 scapolite (wernerite) which it resembles in composition, and also from 
 the feldspar group. 
 
 Jadeite, one of the kinds of pale-green stones used in China for 
 ornaments, called feitsui, has the high specific gravity of zoisite, but 
 it has nearly the composition of oligoclase, if the iron and magnesia 
 be excluded; analysis by Damour affording Silica 59°17, alumina 
 22°58, iron protoxide 1°56, magnesia 1°15, lime 2°68, soda 12°93=100°07. 
 It is the material of some of the ornaments in the Swiss lake-dwell- 
 ings. 
 
 ‘Allanite.—A cerium epidote, of a pinchbeck-brown to brownish- 
 black and black color, submetallic to pitch-like and resinous in lustre, 
 crystallizing in the monoclinic system, and with the angles nearly of 
 epidote. H.=5°5-6. G.=8-4°2. . 
 
 B.B. fuses easily and swells up to a dark, blebby magnetic glass. 
 Most varieties gelatinize with hydrochloric acid, but not after igni- 
 tion. Found in Norway, Sweden, Greenland, Scotland ; at Snarum, 
 near Dresden ; in Massachusetts, at the Bolton quarry ; in New York, 
 at Moriah in Essex County, Monroe in Orange County ; in New Jersey, 
 at Franklin; in Pennsylvania, at East Bradford and Eaton ; in Vir- 
 ginia, Amherst County ; in Canada, at St. Paul’s. 
 
 Orthite isa variety in long slender crystals. Muromontite, Bodenite, 
 and Michaelsonite are related minerals. 
 
 Gadolinite. A mineral of a greenish-black color, containing lithium, 
 cerium, and barium, from Sweden, Greenland, and Norway. Crystals 
 monoclinic, with 7\ J=116°. H.=65-7. G.=4-45. 
 
 Mosandrite. Reddish-brown to dull greenish or yellowish-brown 
 silicate of cerium, lanthanum and didymium, calcium, and titanium. 
 H.—4. G.=2-9-3:03. From Brevig, Norway. 
 
 Iwaite (Yenite). In trimetric striated prisms, of an iron-black to 
 grayish-black color, JAJ=112° 38’. H.=5°0-6. G.=37-42. In 
 composition a calcium-iron silicate in which part of the iron is in 
 the sesquioxide state. From Elba; Fossum and Skeen in Norway, 
 etc. Also reported as occurring at Cumberland, R. I., and Milk Row 
 quarry, in Somerville, Mass. The name Jlvaite is derived from the 
 Latin name of the Island of Elba, 
 
264 DESCRIPTIONS OF MINERALS. 
 Axinite. 
 
 Triclinic. In acute-edged oblique rhomboidal prisms ; 
 Par=134° 45’, rAu=115° 38’, PAw=135° 31’. Cleavage 
 indistinct. Also rarely massive or lamellar. 
 
 Color clove-brown ; differing some- 
 what in shade in three directions, being 
 trichroic. Lustre vitreous. ‘Transpa- 
 rent to subtranslucent. Brittle. H.= 
 6-5-7. G.=8°2%. Pyro-electrie. 
 
 Composition. A unisilicate, afford- 
 ing boron trioxide, and_ containing 
 boron among its bases. One analysis 
 afforded Silica 43°68, boron trioxide 
 5-61, alumina 15°63, iron sesquioxide 
 9-45, manganese sesquioxide 3°08, lime 
 20-92, magnesia 1°70, potash 0°64= 
 100-43. B.B. fuses easily with intum- 
 escence to a dark-green or black glass, 
 imparting a pale-green color to the 
 flame, which is due to the boron. 
 
 Diff. Remarkable for the sharp thin edges of its crystals, 
 and its glassy brilliant appearance, without cleavage. The 
 crystals are implanted, and not disseminated like garnet. In 
 one or all of these particulars, and also in blowpipe reaction, 
 it differs from any of the titanium ores. 
 
 Obs. Occurs at St. Cristophe in Dauphiny; at Kongs- 
 berg in Norway; Normark in Sweden; Santa Maria, in 
 Switzerland ; Cornwall, England ; Thum in Saxony, whence 
 the name Z'hummerstein and Thumite. 
 
 In the United States it has been found at Phippsburg and 
 Wales in Maine; and at Cold Spring, New York. 5 
 
 Danburite. A silicate which contains, like axinite, boron trioxide. 
 Composition : Silica 48-8, boron trioxide 28-5, lime 22°7, Occurs with 
 oligoclase and orthoclase in imbedded masses of a pale-yellow color, 
 at Danbury, Conn. H.=7, G.=2°96-2°96. 
 
 
 
 Iolite.—Dichroite. Cordierite. 
 
 Trimetric. In rhombic prisms of 120°, and in 6 and 12- 
 sided prisms. Also massive. Cleavage indistinct ; but crys- 
 tals often separable into layers parallel to the base, especially 
 after partial alteration. 
 
 Color various shades of blue, looking often like a pale or 
 
MICA GROUP. 265 
 
 dark blue glass; often deep blue in direction of the axis, and 
 yellowish gray transversely. Streak uncolored. Lustre vit- 
 reous. ‘lransparent to translucent. Brittle. H.=%-1'5. 
 G. =2°6-2°%. 
 
 Composition. A silicate of aluminum, magnesium and 
 iron, corresponding to Silica 49:4, alumina 33-9, magnesia 
 8-8, iron protoxide 7°9=100. B.B. loses its transparency 
 and with much difficulty fuses. 
 
 Diff. The glassy appearance of iolite is so peculiar that it 
 can be confounded with nothing but blue quartz, from which 
 it is distinguished by its fusing on the edges. It is easily 
 scratched by sapphire. 
 
 Obs. Found at Haddam, Conn., in granite ; also in gneiss 
 at Brimfield, Mass.; at Richmond, N. H., in talcose rock. 
 The principal foreign localities are at Bodenmais in Bavaria; 
 Arendal, Norway; Capo de Gata, Spain; Tunaberg, Fin- 
 land ; also Norway, Greenland and Ceylon. 
 
 The name iolite is from the Greek ion, violet, alluding 
 to its color ; it is also called dichroite, from dis, twice, and 
 chroa, color, owing to its having different colors in two di- 
 rections. 
 
 Occasionally employed as an ornamental stone, and is cut 
 so as to present different shades of color in different direc- 
 tions. 
 
 Iolite exposed to the air and moisture undergoes a gradual altera- 
 tion, becoming hydrous, and assuming a foliated micaceous structure, 
 so as to resemble talc, though more brittle and hardly greasy in feel. 
 Hydrous Iolite, Fahlunite, Chlorophyllite, and Hsmarkite, are names 
 that have been given to the altered iolite ; and Gigantolite and a num- 
 ber of other like minerals are of the same origin. (See p. 815.) 
 
 MICA GROUP. 
 
 The minerals of the mica group are alike in having 
 (1) their crystals monoclinic ; (2) the front plane angle of 
 the base, or of the cleavage laminz, 120°; (3) cleavage emi- 
 nent, parallel to the base, affording very thin laminew; and 
 (4) aluminum and potassium among the essential constituents. 
 The combining or quantivalent ratio for the bases and sili- 
 con is usually 1 to 1 in Biotite, Phlogopite, and Lepidome- 
 lane; 1 to more than 1 in Muscovite, Lepidolite, etc. 
 
~66 DESCRIPTIONS OF MINERALS. 
 
 The ordinary light-colored micas are mostly Muscovite, and 
 the black, mostly Biotite. Lepidolite is a light-colored mica 
 containing lithia ; and Lepidomelane a black mica containing 
 more iron than biotite. Muscovite and biotite are so closely 
 related that crystals of the latter often occur that are fin- 
 ished out uninterruptedly by muscovite, the axial lines of the. 
 one continuous with those of the other; and such crystals 
 are sometimes several inches across. There is here a com- 
 
 pound structure chemically, put no twinning in the crystal- 
 lization. When a thin plate of mica is struck with a pointed 
 
 awl or other tool a symmetrical star of six rays is produced, 
 the rays being cleavage lines parallel to the sides of the 
 rhombic prism J and the shorter diagonal. 
 
 Biotite. 
 
 Monoclinic. Crystals usually short erect rhombic or hex- 
 agonal prisms. Common in disseminated scales; also in 
 masses made up of an aggregation of scales. 
 
 Color dark green to black, rarely white. Transparent to 
 opaque. Lustre more or less pearly on a cleavage surface. 
 Optic-axial angle usually less than 1°; crystals appear often 
 to be uniaxial. H.=2°5-3. G.=2-7-3:1. 
 
 Composition. Mostly (K2,Mg,Fe), Al O,, Si, a variety af- 
 forded Silica 40°91, alumina 17°79, iron oxides 10:00, mag- 
 nesia 19-04, potash 9°96. B.B. whitens and fuses on thin 
 edges ; sometimes the flame is red owing to the presence of 
 a little lithium. 
 
 Lepidomelane. Like biotite, but containing more iron oxides and 
 less of magnesia than biotite, and folia brittle. Fuses easily to 2 
 black magnetic globule. Annite (from Cape Ann, Mass.) is near Lepi- 
 domelane. 
 
 Phiogopite. Contains much magnesia and little or no iron. Color 
 yellowish brown to brownish red, somewhat copper-like in its reflec- 
 tions ; also white or colorless. Optic-axial angle 8° to 90°) Hie a-e. 
 G. —2°78-2°85. In erystals and scales in granular limestone. From 
 Gouverneur, Edwards, and other places in. Northern New York ; Stir- 
 ling Mine, and Newton, N.J.; St. Jerome, and Burgess, Canada ; in 
 the Vosges. Aspidolite, from the Tyrol, is a related mica. 
 
 Astrophyllite. A bronze-yellow mica affording nearly 8 per cent. of 
 eee dioxide. From Brevig, Norway, and El Paso County, Colo- 
 rado. 
 
MICA GROUP. 267 
 
 Muscovite.—Common Mica. 
 
 Monoclinic. In oblique rhombic prisms of about 120°. 
 Crystals commonly have the acute edge replaced, as in the 
 accompanying figure (plane 7-7). Usu- 
 ally in plates or scales. Sometimes in 
 radiated groups of aggregated scales or 
 small folia. 
 
 Colors from white through green, 
 yellowish and brownish shades ; rarely 
 rose-red. Lustre more or less pearly. 
 Transparent or translucent. Tough 
 and elastic. H.=2-2°5. G.=2:7-8. 
 Optic-axial angle 44° to 78°. 
 
 Composition. A common variety afforded Silica 46:3, 
 
 alumina 36°8, potash 9°2, iron sesquioxide 4°5, fluoric acid 
 0-7, water 1°3=99°3. Often contains 3 to 5 per cent. of 
 water, and thus passes to a hydrous mica called Margaro- 
 dite. (See page 313). B.B. whitens and fuses on the thin- 
 nest edges, but with great difficulty, to a gray or yellow 
 lass. 
 F A variety in which the scales are arranged in a plu- 
 mose form is called plwmose mica; another, in which the 
 plates have a transverse cleavage, has been termed prismatic 
 MICA. ; 
 
 Diff, Differs from tale and gypsum in affording thinner 
 and much tougher folia, and in being elastic ; but musco- 
 vite when hydrous loses its elasticity, and becomes more 
 pearly in lustre. 
 
 Obs. Muscovite is a constituent of granite, gneiss and mica 
 schist, and gives to the latter its schistose structure. It also 
 occurs in granular limestone. Plates two and three feet in 
 diameter, and perfectly transparent, have been obtained at 
 Alstead, and Grafton, New Hampshire, and it has been 
 mined at these places, and in Orange and elsewhere. Other 
 good localities are Paris, Me.; Chesterfield, Barre, Brimfield, 
 and South Royalston, Mass.; near Greenwood Furnace, War- 
 wick and Edenville, Orange County, and in Jefferson and 
 St. Lawrence counties, N. Y.; Newton and Franklin, N. J.; 
 near Germantown, Pa.; Jones’s Falls, Maryland. Oblique 
 prisms from near Greenwood are sometimes six or seven 
 inches in diameter. Western North Carolina affords much 
 mica for commerce. 
 
 
 
268 DESCRIPTIONS OF MINERALS, 
 
 A green variety occurs at Unity, Maine, near Baltimore, 
 Md., and at Chestnut Hill, Pa. Prismatic mica is found at 
 Russel, Mass. 
 
 On account of the toughness, transparency, and the thin- 
 ness of its folia, mica was formerly used in Siberia for glass in 
 windows, whence it has been called Muscovy glass. It is in 
 common use for lanterns, and also for the doors of stoves, 
 and other purposes which demand a transparent substance 
 not affected by heat. 
 
 Lepidolite, or Lithia mica. Resembles muscovite. Color rose-red, 
 and lilac to white; in crystalline plates and. aggregations of scales. 
 It contains from 2 to 5 percent. of lithia, and hence B.B. imparts & 
 deep crimson color to the flame. 
 
 From Rozena in Moravia; Zinnwald in Bohemia (the Zinnwaldite) ; 
 Saxony ; the Ural ; Sweden; Cornwall; Paris, and Hebron, Maine ; 
 Chesterfield, Mass.; Middletown, Conn. The red mica of. Goshen is 
 muscovite. 
 
 Cryophyilite has the same constituents as lepidolite. It fuses easily 
 in the Hame of a candle. From Cape Ann, Mass. 
 
 SCAPOLITE GROUP. 
 
 The Scapolite species are dimetric in crystallization, 
 usually white in color or of some light shade, and analyses 
 afford alumina and lime with or without soda. The lime 
 scapolites are unisilicate in ratio ; the others, containing 
 alkali, have, with one exception, more silica than this ratio 
 requires. 
 
 Wernerite.—Scapolite 
 
 Dimetric. 1: 1=136° 7’. Cleavage rather indistinct paral- 
 lel with 7-2 and JZ. Also massive, sub- 
 lamellar, or sometimes faintly fibrous 
 
 I in appearance. 
 
 Colors light; white, gray, pale blue, 
 greenish or reddish. Streak uncolored. 
 Transparent to nearly opaque. Lustre 
 usually a little pearly. H.=5-6. G.= 
 2°6-2°8. 
 
 Composition. 4(Ca,Na,)3A1),0;.51;= 
 Silica 48-4, alumina 28°5, lime 1871, 
 
 soda 5-0=100. B.B. fuses easily with intumescence to a 
 
 white glass. Imperfectly decomposed by hydrochloric acid. 
 
 
 
UNISILICATES. 2969 
 
 Diff. Its square prisms and the angle of the pyramid at 
 summit are characteristic. In cleavable masses it resembles 
 feldspar, but there is a slight fibrous appearance often dis- 
 tinguished on the cleavage surface of scapolite, which is 
 peculiar. It is more fusible than feldspar, and has higher 
 specific gravity. Spodwmene has a much higher specific 
 gravity, and differs in its action before the blowpipe. Zadu- 
 lar spar is more fibrous in the appearance of the surface, 
 and is less hard; it also gelatinizes with acids. 
 
 Obs. Found mostly in the older crystalline rocks, and also 
 in some voleanic rocks. It is especially common in granular 
 limestone. Fine crystals occur at Gouverneur, N. Y., and 
 at Two Ponds and Amity, N. Y.; at Bolton, Boxborough 
 and Littleton, Mass.; at Franklin and Newton, N. J. It 
 occurs massive at Marlboro’, Vt.; Westfield, Mass.; Monroe, 
 Ct. Foreign localities are at Arendal, Norway; Wirmland, 
 Sweden; Pagas in Finland, and also at Vesuvius, whence 
 come the small crystals called meionite. 
 
 Nuttallite, Glaucolite, are varieties of this species. 
 
 Ekebergite resembles wernerite, being distinguishable from it only 
 by chemical analysis. Dipyre also is near wernerite, but contains 
 more silica and 10 per cent. of soda; from the Pyrenees. 
 
 Meionite, a lime seapolite, is like wernerite in its crystals, but has 
 ae formula (4Ca3Al), O,, Si,, being a true unisilicate. From Monte 
 
 omma., 
 
 Mizzonite and Marialite resemble meionite. Paranthine and Sar- 
 colite are other related unisilicate species. 
 
 Nephelite.—Nepheline. 
 
 Hexagonal. In hexagonal prisms with replaced basal 
 edges; OA1=135° 55’. Also massive ; sometimes thin col- 
 umnar. 
 
 Color white, or gray, yellowish, greenish, bluish-red. 
 Lustre vitreous or greasy. Transparent to opaque. H.= 
 5°56. G.=2°5-2°65. a. 
 
 Composition. (Nay, K,)-A10,8i,= (if Na: K=5: 1) Sili- 
 ca 44-2, alumina 33-7, soda 16:9, potash 5:2—100; a little 
 lime is usually present. B.B. fuses quietly to a colorless 
 glass. Decomposed by hydrochloric acid, and the solution 
 gelatinizes on evaporation. ‘The name nephelite alludes to 
 the mineral becoming clouded in acid. Nephelite includes 
 the glassy crystals from Vesuvius called Sommite, and also 
 hexagonal crystals in other volcanic rocks; and a massive 
 variety, of greasy lustre, called Zi«olite, from the Greek 
 
20 DESCRIPTIONS OF MINERALS. 
 
 elaion, oil. Altered crystals are in part the mineral Gie- 
 seckite. 
 
 Diff. Distinguished from scapolite and feldspar by the 
 greasy lustre when massive, and its forming a jelly with 
 acids ; from apatite by the last character, and also its hard- 
 ness. 
 
 Obs. Nephelite is the prominent constituent of nephelin- 
 doleryte or nephelinyte, and phonolyte, and occurs also In 
 some other eruptive rocks; and it also enters into the con- 
 stitution of miascyte, zircon-syenyte, metamorphic rocks. 
 Among the localities are Vesuvius and C. di Bove, in Italy ; 
 Katzenbuckel, near Heidelberg; Aussig in Bohemia; and 
 as elwolite, Brevig, Norway; in Siberia; in the Ozark 
 Mountains, Arkansas ; in Litchfield, Maine. 
 
 Cancrinite. Crystals like those of nephelite, and compo- 
 sition similar, except the presence of some carbonates and 
 usually water. Color white, gray, yellow, green, blue, or 
 reddish; H.=5-6. G.=2-4-2°5. On account of the car- 
 ponates it effervesces in acids. B.B. fuses very easily. 
 
 Occurs in crystalline rocks at Miask in the Ural; in Nor- 
 way ; Transylvania ; and at Litchfield in Maine, with elzo- 
 lite and sodalite. Supposed to be altered nephelite. 
 
 Microsommite is near. Sommite (nephelite). 
 
 Sodalite. 
 
 Isometric. In dodecahedrons; cleavage dodecahedral. 
 Color brown, gray, or blue. H.=6. G.=2°25-2'3. 
 
 Composition. Na, Al O, Si,+4 Na Cl=Silica 37-1, alumina 
 31-7, soda 19-2, sodium 4°7, chlorine 7°3=100. B.B. fuses 
 with intumescence to a colorless glass. Decomposed by hy- 
 drochloric acid, and the solution gelatinizes on evaporation. 
 
 Occurs in eruptive and metamorphic rocks. Found in Si- 
 cily ; near Lake Laach ; at Miask ; in Norway ; West Green- 
 land ; of a blue color at Litchfield, Me.; and lavender-blue 
 at Salem, Mass. 
 
 Huaiiynite (or Hauyne) ‘and Nosite (or Nosean) are related minerals 
 from lavas or other eruptive rocks; and Jttnerite is altered hatiynite 
 
 or nosite. Isometric. In dodecahedrons. Color bright blue, occasion- 
 ally greenish. Transparent to translucent. H.=6. G@.=2°4-2°. 
 
 Lapis-Lazuli.— Ultramarine. 
 
 Isometric. In dodecahedrons; cleavage imperfect. Usual- 
 ly massive. Color rich Berlin or azure blue. Lustre vitre- 
 ous. ‘Translucent to opaque. H.=5'5. G.,=23-2°d. 
 
™ 
 
 UNISILICATES, Para’ 
 
 Composition. Silica 45°5, alumina 31°8, soda 9:1, lime 
 3°5, iron 0°8, sulphuric acid 5:9, sulphur 0°9, chlorine 0°4, 
 water 0°1=98:0. B.B. fuses to a white translucent or 
 opaque glass, and if calcined and reduced to powder loses 
 its color in acids; is decomposed with the evolution of 
 hydrogen sulphide, and the solution gelatinizes on evapora- 
 tion. ‘The color of the mineral is supposed to be due to 
 sodium sulphide. The mineral is not homogeneous, but the 
 exact nature of the ultramarine species at the basis of it is 
 not yet ascertained. 
 
 Obs. Found in syenyte and granular limestone, and is 
 brought from Persia, China, Siberia, and Bucharia. The 
 specimens often contain scales of mica and disseminated 
 
 -pyrites. 
 
 The richly-colored lapis- lazuli is highly esteemed for 
 costly vases, and for inlaid work in ornamental furniture. 
 It is also used in the manufacture of mosaics. When pow- 
 dered it constitutes a beautiful and durable blue paint, 
 called Ultramarine, which has been a costly color. The 
 discovery of a mode of making an artificial ultramarine, 
 quite equal to the native, has afforded a substitute at a com- 
 paratively cheap rate. This artificial ultramarine consists 
 of silica 45°6, alumina 23°3, soda 21°5, potash 1°7, lime 
 trace, sulphuric acid 3°8, sulphur 1-7, iron 1:1, and chlorine 
 a small quantity undetermined. It has taken the place in 
 the arts, entirely, of the native lapis-lazuli. : 
 
 Leucite.—Amphigene. 
 
 Dimetric. Form very nearly that of the trapezohedron 
 represented in the figure. Cleavage imper- 4 
 fect. Usually in dull glassy crystals, of a <| 
 grayish color; sometimes opaque-white, dis- 
 seminated through lava. ‘Translucent to 
 
 opaque. H.—5°5-6. G.=2°5. Brittle. [/ 
 ' Composition. K,AlO, Siy= Silica 55:0, \ are 
 
 alumina 23°5, potash 21°5=100. 3B.B. infu- 
 sible. Moistened with cobalt nitrate and ig- 
 
 —nited assumes a blue color. Decomposed by hydrochloric 
 
 acid, without gelatinizing. ; 
 Diff. Distinguished from analcite by its hardness and in- 
 fusibility. 
 Obs. In volcanic rocks, and abundant in those of Italy, 
 
nie DESCRIPTIONS OF MINERALS, 
 
 especially at Vesuvius, where crystals occur from the size of 
 a pin’s head to a diameter of an inch. Also found in the 
 Leucite Hills, northwest of Point of Rocks, Wyoming Ter- 
 ritory. 
 
 The name leucite is from the Greek lewkos, white. 
 
 FELDSPAR GROUP. 
 
 I. RELATIONS OF THE SPECIES OF FELDSPAR. 
 
 The species of the Feldspar Group are related— 
 
 A. In crystallization: (1) the forms being all oblique; 
 (2) the angle of the fundamental rhombic prism J, in each, 
 nearly 120°; (3) the other angles differing but little, al- 
 though part of the species are monoclinic and part tri- 
 clinic ; and (4) there being two directions of easy cleavage, 
 one, the most perfect, parallel to the basal plane O, and the 
 other parallel to the shorter diagonal section, with the in- 
 tervening angle either 90° (as in the monoclinic species or- 
 thoclase and hyalophane), or nearly 90° (as in the triclinic 
 species). 
 
 B. In composition: (1) the only element in the sesquiox- 
 ide state being aluminum, and those in the protoxide state 
 either calcium, barium, sodium, or potassium, or two or 
 three of these bases together; (2) the ratio of 1 atom of R 
 to 1 of R being constant ; (3) the amount of silica in the 
 Species increasing with the proportion of alkali, being that 
 of a unisilicate in the pure lhme-feldspar, anorthite, that 
 of a tersilicate in the soda-feldspar, albite, or potash-feldspar, 
 orthoclase, and so directly proportioned to the alkali, that 
 the amount in any lime-and-soda feldspar may be deduced 
 by taking the lime (or calcium) as existing in the state of a 
 unisilicate, and the soda in that of a tersilicate, and adding 
 the two together. 
 
 Anorthite has the formula CaAl O, §i.. 
 Albite #3 be Na, Al O,, Sig. 
 
 The constitution of a species containing Ca and Na, in 
 
 the ratio of 1 to1 for the protoxide portion may be ob- 
 
‘FELDSPAR GROUP. mo 
 
 tained as follows. Adding together the anorthite and albite 
 formulas, we have CaNa,Al, O., Si, 3 then dividing by 2, the 
 formulas becomes 3Ca}Na,Al0,,. Si, which expresses the 
 composition of andesite. With 3 parts of the Ca unisili- 
 cate, and 1 of the Na, tersilicate, the composition is that 
 of labradorite. So it is for other combinations, that is for 
 other species between anorthite and albite in composition. 
 The quantivalent ratio for the R, Al, Si, in the several 
 species of the group, is as follows: V means ¢riclinic in 
 crystallization, and IV monoclinic. 
 
 SYSTEM OF SYSTEM OF 
 RATIO. CRYSTALLIZA- RATIO. CRYSTALLIZA- 
 TION. TION. 
 Anorthite, 1:3:4 Vs Oligoclase, 1:3:9 Ve 
 Labradorite, 1:3:6 V, Albite, 1318 V. 
 Hyalophane, 1:3:8 IV, Microcline, 1:38:12 Ve 
 Andesite, L075 ¥, Orthoclase, 1:3 :12 IV. 
 
 These are the normal ratios; but there is some variation 
 from them in the analyses, part of which is variation in 
 actual composition, and part a result of interlamination or 
 mixture of two feldspars together. Thus, orthoclase occurs 
 mixed with microcline, albite, or oligoclase. But while such 
 mixtures account for the soda found in some analyses of 
 orthoclase, it does not for that in all, since soda does occur 
 in many specimens of pure orthoclase, replacing part of the 
 potash. It is the same with the triclinic feldspar micro- 
 cline, which has the composition of orthoclase, and may 
 have the alkali portion all potash or part soda, one analysis 
 of typical microcline giving only 0:48 of soda, It is, hence, 
 not safe to calculate the percentage of orthoclase present 
 in a feldspar from the percentage of potash. Moreover, 
 potash is present in much albite. 
 
 The above ratios show that anorthite has for the ratie 
 between R+R and Si, 4: 4, or 1:1, as in true unisilicates : 
 while in albite and orthoclase, the same ratio ig 4:12 or 
 1:3, that of a tersilicate, as above stated. 
 
 C. In physical characters: the hardness being between 6 
 
 18 
 
7 a DESCRIPTIONS OF MINERALS. 
 
 and %; the specific gravity, between 2-44 and 2°75 ; lustre 
 vitreous, but often pearly on the face of perfect cleavage ; 
 and each species transparent to subtranslucent. 
 
 II. Actprc AND Basic FELDSPARS. 
 
 Oligoclase, albite, and orthoclase are called acidic feld- 
 spars, because of the large amount of the acidic element, 
 silicon, in their constitution, analyses giving 60 to 70 per 
 cent. of silica; and labradorite and anorthite are called 
 basic feldspars, the amount of silica being 42 to 55 per 
 cent. Correspondingly, eruptive, and metamorphic rocks 
 ‘» which either of the acidic feldspars is a prominent con- 
 stituent—for example, granite, gneiss, trachyte, true por- 
 phyry—are called acidic rocks ; while those rocks in which 
 basic feldspars are constituents—like doleryte, and a large 
 part of eruptive rocks—are called basic rocks. 
 
 III. DistincTIONS OF THE TRICLINIC FELDSPARS. 
 
 The triclinic feldspars are distinguished from the mono- 
 clinic (e. g. orthoclase) by the occurrence of very fine stria- 
 tions on the cleavage surface, sometimes too fine to be seen 
 without a good pocket-lens. These striations are due to 
 multiple twinning parallel to the other cleavage face, as ex- 
 plained on page 5%. ‘They are rarely absent from triclinic 
 feldspar crystals. They are best brought out by transmitted 
 polarized light, in which a transverse section of the crys- 
 tal is seen banded with spectrum colors, each band corre- 
 sponding to one plate of the twin structure. 
 
 The triclinic feldspars, andesite excepted, may be dis- 
 tinguished from one another by an optical method when 
 the cleavage direction can be made out. For this purpose 
 a plate is prepared parallel to the plane of easiest cleavage. 
 In such a plate the multiple twinning is parallel to the other 
 cleavage plane, or the shorter diagonal. When the plate is 
 placed on the stage of a polariscope, between crossed Nicol- 
 prisms, as the stage is revolved, the adjoining bands of color 
 become dark alternately, and the angle through which the 
 
FELDSPAR GROUP. 275 
 
 plate has to be revolved for the change between consecutive 
 bands varies for different species, it being 54° to 74° for 
 anorthite, 10° to 14° for labradorite, 4° to 8° for oligoclase, 
 6° to 8° for albite, and 30° for microcline. The shorter 
 diagonal of the crystal bisects this angle, so that the angle 
 made with this diagonal is 27° to 87° for anorthite, 5° to 
 © for labradorite, 2° to 4° for oligoclase, 34° to 4° for albite, 
 and 15° for microcline. Obtaining cleavage plates for such 
 measurements in the case of slices for microscope investiga- 
 tion, is seldom possible, and when not so, the only certain re- 
 source for the distinguishing of triclinic feldspars is chemical 
 analysis. These feldspars have been called plagioclase (from 
 the Greek words for oblique and fracture), as if all were of 
 one species. The term is a convenient cover for ignorance. 
 
 IV. DisTINcTIONS FROM OTHER MINERALS. When in 
 crystals, the form is sufficient to determine a feldspar ; so also 
 the fact of two unequal cleavages inclined to one another at 
 84° to 90°, one of them quite perfect. No fibrous, columnar, 
 _ OF micaceous varieties are known. They differ from rho- 
 donite, by the absence of a manganese reaction ; from spodu- 
 mene, by the absence of a lithia reaction as well as cleavage 
 angles; from scapolite, by form, the cleavage angles, the 
 more difficult fusibility ; from nephelite, by form, and also 
 in difficult fusibility, and not gelatinizing with acids, ex- 
 cept in the case of anorthite and labradorite, which fuse 
 with but little more difficulty than nephelite, and often will 
 gelatinize. 
 
 Anorthite.—Indianite. Lime Feldspar 
 
 Triclinic. Angle between the two cleavage planes 85° 50’ 
 and 94° 10’. Crystals tabular. Also massive granular or 
 coarse lamellar. Color white, grayish, or reddish. 
 
 Composition. CaAl O; Si,=Silica 43°1, alumina 36°8, lime 
 20°1=100. 8B.B. fuses with much difficulty to a colorless 
 glass ; decomposed by hydrochloric acid, the solution gela- 
 
 tinizes on evaporation. . 
 Oods. Occurs in basic eruptive rocks; also in some meta- 
 
276 DESCRIPTIONS OF MINERALS. 
 
 morphic rocks. Found in the lava of Vesuvius; in the 
 Tyrol ; Faroe Islands, Iceland ; in imbedded crystals in some 
 doleryte of the Connecticut Valley. 
 
 At Hanover, N. H., anorthite crystals occur altered to a silicate 
 which afforded, in an analysis by Hawes, only 2:2 of lime, and, in place 
 of the rest of this ingredient, 7°11 of potash, 3-77 of soda, 1°10 of iron- 
 sesquioxide, and 2°67 of water, with 30°05 of alumina and 52°52 of 
 silica ; which compound, if the water be made basic, has the ratio 
 nearly of labradorite, though distinct from that species in the alkalies, 
 and also in specific gravity, which is 9-96 or very nearly 3. It has some 
 relation to zoisite, and to typical saussurite, but is widely different 
 +n constituents and ratio; it is related also to jadeite. (See page 
 263.) 
 
 Labradorite.—Lime-soda Feldspar. Labrador Feldspar. 
 
 Triclinic. Angle between the cleavage planes 93° 20' and 
 86° 40’. Usually in cleavable massive forms. 
 
 Color dark gray, brown, or greenish brown ; also white or 
 colorless. Often a series of bright chatoyant colors from in- 
 ternal reflections, especially blue and green, with more or 
 less of yellow, red, and pearl-gray. 
 
 Composition. 3CafNa,Al On Si:= Silica 52°9, alumina 30°3, 
 lime 12:3, soda 4*5—100. Sometimes contains a little potash 
 in place of the soda. B.B. fuses quite easily to a colorless 
 glass. Only partially decomposed by hydrochloric acid. 
 
 Obs. A constituent of the larger part of eruptive rocks, as 
 doleryte, and amphigenyte, and many lavas ; andalso of some 
 metamorphic rocks. Occurs as an ingredient in part of the 
 Archean rocks in North America, and was named from its 
 first discovery in Labrador. 
 
 Andesite. Triclinic. Angle between the cleavage planes 87°-88”. 
 Near labradorite in composition. The- formula Ca 4Na, Al O,, Sip= 
 Silica 59°8, alumina 255, lime 7'0, soda 7°7-=100: 0. 
 
 Hyalophane. Monoclinic, and hence angle between the cleavage 
 planes 90°. <A baryta feldspar ; the formula like that of andesite, ex- 
 cepting the substitution of Ba for Caand Ke for Nas. It has been found 
 in the Binnenthal, Switzerland, and at J akobsberg, Sweden. 
 
 ' A baryta-feldspar, having the ratio of andesite, 1:3:8, has been 
 
 am. which is ¢riclinic, and approaches oligoclase in optical char- 
 acters. 
 
 Oligoclase.—Soda-lime Feldspar. 
 
 Triclinic. Angle between the cleavage planes 93° 50' and 
 86°10’. Commonly in cleavable masses. Also massive. 
 _ Color usually white, grayish white, grayish green, green- 
 a Beret Transparent, subtranslucent. H.=6°% G= 
 
FELDSPAR GROUP, aie 
 
 Composition. 4Ca%Na,Al O,, Sis=Silica 61:9, alumina 24-1, 
 lime 5°2, soda 8°8=100. A portion of the soda is usually 
 replaced by potash. B.B. fuses without difficulty ; not de- 
 composed by acids. 
 
 Obs. It occurs in granite, syenyte, and various meta- 
 morphic rocks, especially those containing much silica ; and 
 in such case usually associated with orthoclase. Sunstone is 
 in part oligoclase containing disseminated scales of hematite 
 giving bright reflection from the interior of the stone. Oc- 
 curs in Norway. Moonstone is in part a whitish opalescent 
 variety. Oligoclase occurs at Unionville, Pa.; Haddam, 
 Conn. ; Mineral Hill, Del. ; Chester, Mass. , ete, 
 
 Albite. 
 
 Triclinic. Angle between the cleavage planes 93° 36’, 
 and 83° 24’. Figures 1 to 6 represent some of its forms ; 
 
 1. 2. 3. 6. 
 rm bed) 
 WY ol 
 4, 
 
 
 
 
 
 
 ‘2 and 3’are twin crystals, The crystals are usually more or 
 less thick and tabular. Also massive, with a granular or 
 lamellar structure. Color white ; occasionally light tints of 
 bluish white, grayish, reddish and greenish. Transparent 
 to subtranslucent. 
 
 Composition. Na,Al0O,,Si,=Silica 68:6, alumina 19°6, 
 soda 11°8=100°0. B.B. fuses to a colorless or white glass, 
 imparting an Intense yellow to the flame. Not acted upon 
 by acids. 
 
278 DESCRIPTIONS OF MINERALS. 
 
 Cleavelandite is a lamellar variety occurring in wedge- 
 shaped masses at the Chesterfield albite vein, Mass. 
 
 Obs. Albite occurs in some granites and gneiss, and is 
 most abundant in granite veins. Fine crystals occur at 
 Middletown and Haddam, Conn., at Goshen, Mass., and 
 Granville, N. Y. ; Unionville, Delaware County, Penn. 
 
 The name albite is from the Latin albus, white. 
 
 Wlicrocline. 
 
 A potash-feldspar, very close to the following species in 
 angles, and also in physical characters, and identical with it 
 in composition. But it 1s very slightly triclinic, the angle 
 between its cleavage planes varying but 16’ from 90°; and 
 hence its cleavage surface shows usually the fine striations 
 exhibited with rare exceptions by all the triclinic feldspars. 
 Colors white, flesh-red, copper-green. ‘The last is what has 
 been called Amazon-stone ; as heat destroys the color it has 
 been supposed to be of organic origin. 
 
 Occurs in the zircon-syenyte of Norway ; also in the Urals ; 
 Greenland; Labrador; Everett, Mass. ; Redding, Conn.; 
 Delaware ; Chester County, Penn.; White Mountain Notch, 
 green ; Pike’s Peak, Amazon-stone ; Magnet Cove, Ark. 
 
 Orthoclase-—Common Feldspar. 
 
 Monoclinic ; and hence angle between the cleavage planes 
 90°. Figures 1 to 4 represent common forms, and 5 to 8 
 twin crystals. Usually in thick prisms, often rectangular, 
 and also in modified tables. Also massive, with a granular 
 structure, or coarse lamellar; also fine-grained almost flint- 
 like in compactness. Colors light; white, gray, and flesh- 
 red common ; also greenish and bluish-white and green. 
 
 Composition. K, Al Oi Sig — Silica 64:7, alumina 18-4, 
 potash 16-°9=100. Soda sometimes replaces a portion of 
 ne oe B.B. fuses with difficulty; not acted on by 
 acids. 
 
 Common feldspar includes the common subtranslucent 
 varieties; Adularia, the white or colorless subtransparent 
 specimens, a name derived from Adula, one of the highest 
 peaks of St. Gothard. Sanidin or glassy feldspar includes 
 transparent vitreous crystals, found in trachytes and lavas ; 
 but some of the “glassy feldspar” belongs to the species 
 anorthite. Loxoclase is a grayish variety with a pearly or 
 greasy lustre that contains much soda. 
 
FELDSPAR GROUP. 279 
 
 Moonstone is an opalescent variety of adularia, having 
 when polished peculiar pearly reflections, Swnstone is simi- 
 lar; but contains minute scales of mica. Aventurine feld- 
 
 
 
 
 
 spar often owes its iridescence to minute crystals of specular 
 or titanic iron, or limonite. Sunstone and moonstone are 
 mostly oligoclase, and so isa large part of aventurine feld- 
 spar. 
 
 Diff Distinguished from the other feldspars by its right- 
 angled cleavage and the absence of striated surfaces. 
 
 Obs. Orthoclase is one of the constituents of granite, sye- 
 nyte, gneiss, and other related rocks ; also of porphyry, and 
 trachyte ; and it often occurs in these rocks in imbedded 
 crystals. St. Lawrence County, N. Y., affords fine crystals ; 
 also Orange County, N. Y.; Haddam and Middletown, 
 Conn.; Acworth, N. H.; South Royalston and Barre, 
 Mass., besides numerous other localities. Green feldspar 
 occurs at Mount Desert, Me.; an aventurine feldspar at 
 Leiperville, Penn.; adularia at Haddam and Norwich, 
 Conn., and Parsonsfield, Me. A fetid feldspar (sometimes 
 called necronite) is found at Roger’s Rock, Essex County ; 
 at Thomson’s quarry, near 196th Street, New York City, 
 and 21 miles from Baltimore. Carlsbad and Elbogen in Bo- 
 hemia, Baveno in Piedmont, St. Gothard, Arendal in Nor- 
 way, Land’s End, and the Mourne Mountains, Ireland, are 
 some of the more interesting foreign localities. 
 
~ 
 
 280 DESCRIPTIONS OF MINERALS. 
 
 Felsite is compact, uncleavable orthoclase, having the 
 texture of jasper or flint, which it much resembles. It often 
 contains some disseminated silica. It occurs of various col- 
 ors, as white, gray, brown, red, brownish red and black, and 
 is sometimes banded. It is distinguished from flint or Jas- 
 per by its fusibility. 
 
 Felsite is the material of beds or strata in some rock for- 
 mations, and also of dikes or masses of eruptive rocks. It is 
 the base of much red porphyry. The vicinity of Marblehead, 
 Mass., is one of its localities. 
 
 The name feldspar is from the German word Feld, mean- 
 ing field. .It is, therefore, wrong to write it felspar. 
 
 Orthoclase is used extensively in the manufacture of por- 
 celain. The large granite veins of Middletown and Port- 
 land, Conn., are quarried in several places for both orthoclase 
 and quartz for this purpose; the places are often called 
 China-stone quarries. 
 
 Kaolin. This name is applied to the clay that results 
 from the decomposition of feldspar. See Kaolinite, p. 310. 
 
 Ill. SUBSILICATES. 
 
 In the Subsilicates, as stated on page 242, the combin- 
 ing or quantivalent ratio between the bases and silica is 1 
 to less than 1. In Chondrodite, the first of the following 
 species, the ratio is 4:3; in Tourmaline, Andalusite, Cya- 
 nite, and Fibrolite, 3:2. Analyses of Andalusite obtain 1 
 of alumina, Al O,, to 1 of silica, Si0,, giving the oxygen 
 ratio for bases and silica 3: 2. This is the composition also 
 of cyanite and fibrolite ; so that the three species, anda- 
 lusite, cyanite, and fibrolite are the same in constituents 
 and atomic ratio while differing in crystalline form, exem- 
 plifying a case of ¢rimorphism among minerals. 
 
 The ratio 3:2 exists also in Topaz, Euclase and Da- 
 tolite in Titanite or sphene, and in Keilhauite. In Stau- 
 rolite, the ratio was formerly regarded as 2:1; but the 
 most recent analyses, those of Rammelsberg, give 11: 6, or 
 1::1. In datolite and tourmaline the basic constituents 
 include boron ; in titanite and keilhauite, titanium ; in da- 
 
SUBSILICATES. 281 
 
 ( 
 
 tolite, euclase, and part of staurolite, hydrogen, that is, the 
 hydrogen of the water found on analysis. In chondrodite, 
 topaz, and some tourmaline, fluorine replaces part of the 
 oxygen. 
 
 Chondrodite.—Humite in part (Scacchi’s Type II). 
 
 Monoclinic. Cleavage indistinct. Usually in imbedded 
 grains or masses. Color light yellow to brownish yellow, yel- 
 lowish red, and garnet-red. Lustre vitreous, inclining a little 
 to resinous. Streak white, or slightly yellowish or grayish. 
 Translucent or subtranslucent. Fracture uneven. H.=6- 
 65) G.=371-3 25. 
 
 Composition. Mg,O,,8i;; but a portion of the magnesium 
 replaced by iron, and a part of the oxygen by fluorine. A 
 specimen from Brewster’s, New York, afforded Silica 34:1, 
 magnesia 53°7, iron protoxide 7°3, fluorine 4:2, with 0°48 of 
 alumina=99°72. 
 
 B.B. infusible. Decomposed by hydrochloric acid ; the 
 solution gelatinizes on evaporation. 
 
 Diff. As it eccurs only in limestone it will hardly be con- 
 founded with any species resembling it in color when the 
 gangue is present. It does not fuse like tourmaline or gar- 
 net, some brownish-yellow varieties of which it approaches 
 in appearance. The name is from the Greek chondros, a 
 
 rain. 
 
 Obs. Itis abundant in the adjoining counties, Sussex, N. J., 
 and Orange, N. Y., occurring at Sparta and Bryam, N. J., 
 and in Warwick and other places in N. Y.; at the Tilly 
 Foster Iron Mine, Brewster’s, Putnam County, N. Y., it 1s 
 very abundant. At Vesuvius it occurs in small crystals. 
 
 The species was early named Chondrodite, from Finland 
 specimens ; soon afterward small crystals, found in the lavas 
 of Somma (Vesuvius), were named Humite, and both were 
 referred to the same species. It has recently been ascer- 
 tained that under this species, two species of different an- 
 gles and form, but related composition and physical charac- 
 ter, are included. For these species the names Humite and 
 Clinohumite have been adopted. 
 
 Humite is orthorhombic, and embraces part of the Humite 
 crystals of Vesuvius (Scacchi’s Type I.), and some large 
 coarse chondrodite-like crystals found at Brewster’s, N. Y. 
 
 Olinohumite is monoclinic, and includes Scacchi’s Type II. 
 
282 DESCRIPTIONS OF MINERALS. 
 
 of Humite from Vesuvius, and fine chondrodite-like crystals 
 from Brewster’s. 
 Tourmaline. 
 
 Rhombohedral. Usual in prisms of 3, 6, 9, or 12 sides, 
 terminating in a low 3-sided pyramid. The sides of the 
 prisms are often rounded and striated. Other forms are 
 shown in the figures. ‘The common pyramid is the rhombo- 
 
 
 
 hedron —4 in the figures, the angle of which is 133° 8’. The 
 crystals often have unlike secondary planes at the two ex- 
 tremities, as shown in figure 3. Occurs also compact mas- 
 sive, and coarse columnar, the columns sometimes radiating 
 or divergent from a centre. 
 
 Color black, blue-black, and dark brown, common ; also 
 bright and pale red, grass-green, cinnamon-brown, yellow, 
 gray, and white. Sometimes red within and green externally, 
 or one color at one extremity and another at the other. 
 Transparent ; usually translucent to nearly opaque. Di- 
 chroic. Lustre vitreous, inclining to resinous on a surface 
 of fracture. Streak uncolored. Brittle; the crystals often 
 fractured across and breaking very easily. H.=7-0-75. a 
 =3-3°3. 
 
 Composition. (R,, B.,R, ) O05, Shr, in which R includes, in 
 different varieties, Fe, Mg, Na., with often traces also of Ca, 
 Mn, K., Li,; R includes aluminum, with some boron in the 
 trioxide state replacing Al; and a little of the oxygen is 
 sometimes replaced by fluorine. 
 
 A black tourmaline from Haddam afforded on analysis, 
 Silica 37°50, boron trioxide (by loss) 9°02, alumina 30°87, 
 iron protoxide 8°54, magnesia 8°60, lime 1:33, soda 1°60, 
 potash 0°73, water 1-381=100. A red tourmaline from Paris, 
 Maine, afforded Fluorine 1:19, silica 41°16, boron trioxide 
 (by loss) 8°93, alumina 41°53, manganese protoxide 0°95, 
 magnesia 0°61, soda 1°37, potash 2°17, lithia 0°41, water 2°57 
 = 100, 
 
 Tourmaline varies much in color owing to its variations in 
 
SUBSILICATES. 983 
 
 composition ; the dark contain much iron and the lght 
 colors but little. Some of the varieties have received special 
 names. Rudellite is red tourmaline; and Indicolite, blue and 
 bluish-black. Schorl formerly included the common black 
 tourmaline, but the name is not now used. 
 
 The presence of boron trioxide is the most remarkable 
 point in the constitution of this mineral. The colorless, red, 
 and pale-greenish kinds usually contain lithia. B.B. the 
 darker varieties fuse with ease, and the lighter with difficulty. 
 On mixing the powdered mineral with potassium bisulphate 
 and fluor spar, and heating B.B., gives a green flame owing 
 to the boron. 
 
 Diff. The black and the dark varieties generally, are 
 readily distinguished by the form and lustre and absence of 
 distinct cleavage, together with their difficult fusibility. 
 The black when fractured often appear a little like a black 
 resin. The brown variety resembles garnet or idocrase, but 
 is more infusible. The red, green, and yellow varieties are 
 distinguished from any species they resemble by the crystal- 
 line form, the prisms of tourmaline always having 3, 6, 9, 
 or 12 prismatic sides (or some multiple of 3). The electric 
 properties of the crystals, when heated, is another remarka- 
 ble character of this mineral. The test for boron is always 
 good. 
 
 Obs. Tourmalines are common in granite, gneiss, mica 
 schist, chlorite schist, steatite, and granular limestone. 
 They usually occur penetrating the rock. The black crys- 
 tals are often highly polished and at times a foot in length, 
 when perhaps of no larger dimensions than a pipe-stem, or 
 even more slender. This mineral has also been observed in 
 sandstones near basaltic or trap dikes. 
 
 Red and green tourmalines, over an inch in diameter and 
 transparent, have been obtained at Paris and Hebron, Me., 
 besides pink and blue crystals. These several varieties oc- 
 cur also, of less beauty, at Chesterfield and Goshen, Mass. 
 Good black tourmalines are found at Norwich, New Brain- 
 tree, and Carlisle, Mass. ; Alsted, Acworth, and Saddleback 
 Mountain, N. H.; Haddam and Monroe, Conn.; Sara- 
 toga and Edenville, N. Y. ; Franklin and Newton, N. J.; 
 near Unionville, Chester, and Middletown, Penn. ; trans- 
 parent brown at Hunterstown, Canada East ; amber-colored 
 at Fitzroy ; black at Bathurst, and Elmsley, Canada West ; 
 fine greenish yellow at G. Calumet I. 
 
284 DESCRIPTIONS OF MINERALS. 
 
 Dark brown tourmalines are obtained at Orford, N. H.; 
 in thin black crystals in mica at Grafton, N. H. ; Monroe, 
 Ct. ; Gouverneur and Amity, N. Y. ; Franklin and Newton, 
 N. J. A fine cinnamon-brown variety occurs at Kings- 
 bridge and Amity, Orange Co., N. Y. and also south in New 
 Jersey. A gray or bluish-gray and green variety occurs near 
 Edenville. 
 
 The word tourmaline is a corruption of the name used in 
 Ceylon, whence it was first brought to Europe. Lyncurvwm 
 is supposed to be the ancient name for common tourmaline ; 
 and the red variety was probably called hyacinth. 
 
 The red tourmalines, when transparent and free from 
 cracks, such as have been obtained at Paris, Me., are of great 
 value and afford gems of remarkable beauty. They have 
 all the richness of color and lustre belonging to the ruby, 
 though measuring an inch across. The yellow tourmaline, 
 from Ceylon is but little inferior to the real topaz, and is 
 often sold for that gem. ‘The green specimens, when clear 
 and fine, are also valuable for gems. Plates from pellucid 
 crystals cut in the direction of a vertical plane are much 
 used for polariscopes. 
 
 Gehlenite. Tetragonal, like the scapolites, and grayish green in 
 color. G.—2-9-3°07. Formula Ca,Al0,,Si, with some of the Al re- 
 
 placed by Fe, and some of the Ca by Fe and Mg. From Mount 
 Monzoni in the Fassa Valley. 
 
 Andalusite. ° 
 
 Trimetric. In rhombic prisms, which are nearly square ; 
 IAI=90° 48’, Cleavage lateral; sometimes distinct. Also 
 massive and indistinctly coarse columnar, but never fine 
 fibrous. 
 
 Colors gray and flesh-red. Lustre vitreous, or inclining to 
 pearly. ‘Translucent to opaque. Tough. H=75. G= 
 
 3°1-3°3. 
 is 
 
 Composition. AlO,Si=Silica 36:9, alumina 63°1=100. 
 B.B. infusible. Ignited after being moistened with cobalt 
 nitrate assumes a blue color. Insoluble in acids. 
 
 
 
SUBSILICATES. 285 
 
 Chiastolite and macle are names given to crystals of anda- 
 lusite which show a tessellated or cruciform structure when 
 broken across and polished. ‘The above figures represent 
 sections of crystals from Lancaster, Mass. ‘The structure is 
 owing to carbonaceous impurities distributed in the crystal- 
 lizing process in a regular manner along the sides, edges 
 and diagonals of the crystal, ‘Their hardness is sometimes 
 as low as 3. ? 
 
 Diff. Distinguished from pyroxene, scapolite, spodumene, 
 and feldspar, by its infusibility, hardness, and form. 
 
 Obs. Most abundant in clay slate and mica slate, but oc- 
 curring also in gneiss. T'ound in the Tyrol, Saxony, Bavaria, 
 etc.; also in Westford, Mass.;° Litchfield and Washington, 
 Ct. ; Bangor, Me.; Leiperville, Marple, and Springfield, 
 Penn. ; and chiastolite at Sterling and Lancaster, Mass., 
 and near Bellows Falls, Vermont. ‘This species was first 
 found at Andalusia in Spain. 
 
 Fibrolite.—Sillimanite. Bucholzite. 
 
 Orthorhombic. In long, slender rhombic prisms, often 
 much flattened, penetrating the gangue. [A[=96°-98°. 
 A brilliant and easy cleavage, parallel to the longer diago- 
 nal. Also in masses, consisting of aggregated crystals or 
 fibres. Color hair-brown or grayish brown. Lustre vitre- 
 ous, inclining to pearly. Translucent crystals break easily. 
 H. =6-7. ‘ G.=3°2-3°3. 
 
 Composition. Al O,Si, as for andalusite, =Silica 36-9, alu- 
 mina 63°1=100. Moistened with cobalt nitrate and ig- 
 nited assumes a blue color. Infusible alone and with borax. 
 
 Diff. Distinguished from tremolite and the varieties gen- 
 erally of hornblende by its brilliant diagonal cleavage, and 
 its infusibility ; from kyanite and andalusite by its brilliant 
 cleavage, its fibrous structure, and its rhombic crystalline 
 form. 
 
 Obs. Found in gneiss, mica schist, and related metamor- 
 phic rocks. Occurs in the Tyrol, at Bodenmais in Bavaria ; 
 at the White Mountain Notch in N. H.; at Chester and 
 near Norwich, Conn.; Yorktown, N. Y.; Chester, Bir- 
 mingham, Concord, Darby, Penn.; in North Carolina; and 
 elsewhere. Fibrolite was much used for stone implements 
 in Western Europe in the ‘Stone age ;” the locality whence 
 the material was derived is not known. 
 
286 DESCRIPTIONS OF MINERALS, 
 
 Cyanite.—Kyanite. Disthene. | 
 
 Triclinic. Usually in long thin-bladed crystals aggre- 
 gated together, or penetrating the gangue. Sometimes in 
 short and stout crystals. Lateral cleavage distinct. Some- 
 times fine fibrous. 
 
 Color usually light blue, sometimes having a blue centre 
 with a white margin; sometimes white, gray, green, or even 
 black. Lustre of flat face a little pearly. H.=5-7'5, greatest 
 at the ends of the prisms, and least on the flat face of the 
 prism. G, =3'40-3°7. “y 
 
 Composition. AlO,Si, as for andalusite, =Silica 36°9, 
 alumina 63°1=100. Blowpipe characters like those of an- 
 dalusite. 
 
 Diff. Distinguished by its infusibility from varieties of 
 the hornblende family. The short crystals have some re- 
 semblance to staurolite, but their sides and terminations are 
 usually irregular ; they differ also in their cleavage and 
 lustre. The thin-bladed habit of cyanite is very character- 
 istic. 
 
 Obs. Found in gneiss and mica schist, and often accom- 
 panied by garnet and staurolite. 
 
 Occurs in long-bladed crystallizations at Chesterfield and 
 Worthington, Mass.; at Litchfield and Washington, Conn.; 
 near Philadelphia; near Wilmington, Delaware; and in 
 Buckingham and Spotsylvania counties, Va. Short crystals 
 (sometimes called improperly jidrolite) occur in gneiss at 
 Bellows Falls, Vt., and at Westfield and Lancaster, Mass. 
 
 In Europe, at St. Gothard in Switzerland, at Greiner and 
 Pfitsch in the Tyrol, in Styria, Carinthia, and Bohemia. 
 Villa Rica in South America affords fine specimens. | 
 
 The name cyanite is from the Greek kuanos, a dark-blue 
 substance. It is also called disthene, in allusion to the un- 
 equal hardness in different directions, and when white, rhe- 
 tizite. 
 
 Kyanite is sometimes used as a gem, and has some resem- 
 blance to sapphire. 
 
 Topaz. 
 
 Trimetric. ZA [=124° 17’. Rhombic prisms, usually dif- 
 ferently modified at the two extremities. JAI= 124° 17. + 
 Cleavage perfect parallel to the base. 
 
 Color pale yellow ; sometimes white, greenish, bluish, or _ 
 
SUBSILICATES, 287% 
 
 reddish. Streak white. Lustre vitreous. Transparent to 
 
 subtranslucent. Pyro-electric. H.=8. G=3:4-3°65. 
 Composition. AlO,Si, with apart of the oxygen replaced 
 
 “by fluorine=Silica 16°2, silicon fluorid 28:1, alumina 55°7 
 
 
 
 =100. An analysis of one specimen afforded, Silica 34:24, 
 alumina 57°45, fluorine 14°99. B.B.infusible. Some kinds 
 become yellow or of a pink tint when heated. Moistened 
 with cobalt nitrate and ignited assumes a fine blue color. 
 Insoluble in acids. 
 
 Diff. Topaz is readily distinguished from tourmaline and 
 other minerals it resembles by its brilliant and easy basal 
 cleavage. 
 
 Obs. Pycnite isa variety presenting athin columnar struc- 
 ture and forming masses imbedded in quartz, The Physalite 
 or Pyrophysalite of Hisinger is a coarse, nearly opaque va- 
 riety, found in yellowish-white crystals of considerable di- 
 mensions. This variety intumesces when heated, and hence 
 its name from phusao, to blow, and pur, fire. 
 
 Topaz is confined to metamorphic rocks or to veins inter- 
 secting them, and is often associated with tourmaline, beryl, 
 and occasionally with apatite, fluorite, and tin ore. 
 
 Fine topazes are brought from the Uralian and Altai 
 mountains, Siberia, and from Kamschatka, where they occur 
 of green and blue colors. In Brazil they are found of a deep 
 yellow color, either in veins or nests in lithomarge, or in 
 loose crystals or pebbles. Magnificent crystals of a sky-blue 
 color have been obtained in the district of Cairngorm, in 
 Aberdeenshire. The tin mines of Schlackenwald, Zinnwald, 
 and Ebrenfriedersdorf in Bohemia, St. Michael’s Mount in 
 Cornwall, etc., afford smaller crystals. The physalite va- 
 riety occurs in crystals of immense size at Finbo, Sweden, 
 in a granite quarry, and at Broddbo. A well-defined crys- 
 tal from this locality, in the possession of the College of 
 Mines of Stockholm, weighs eighty pounds. Altenberg in 
 
2988 DESCRIPTIONS OF MINERALS. 
 
 Saxony, is the principal locality of pycnite. It is there as- 
 sociated with quartz and mica. | 
 
 Trumbull, Gonn., is a prominent locality of this species 
 in the United States. It seldom affords fine transparent 
 crystals, except of a small size ; these are usually white, oc- 
 casionally with a tinge of green or yellow. ‘The large coarse 
 crystals sometimes attain a diameter of several inches (rare- 
 ly six or seven), but they are deficient in lustre, usually of 
 a dull yellow color, though occasionally white, and often 
 are nearly opaque. Itis found also at Crowder’s Mountain 
 in N. C.; in Utah, in Thomas’s Mountains, and in gold 
 washings in Oregon. 
 
 The ancient ¢opazion was found on an island in the Red 
 Sea, which was often surrounded with fog, and therefore 
 difficult to find. It was hence named from ¢opazo, to seek. 
 This name, like most of the mineralogical terms of the an- 
 cients, was applied to several distinct species. Pliny describes 
 a statue of Arsinoe, the wife of Ptolemy Philadelphus, four 
 cubits high, which was made of topazion, or topaz, but evi- 
 dently not the topaz of the present day, nor chrysolite, 
 which has been supposed to be the ancient topaz. It has 
 been conjectured that it was a jasper or agate ; others have 
 supposed it to be prase or chrysoprase. 
 
 ''opaz is employed in jewelry, and for this purpose its 
 color is often altered by heat. ‘The variety from Brazil as- 
 sumes a pink or red hue, so nearly resembling the Balas 
 ruby, that it can only be distinguished by the facility with 
 which it becomes electric by friction. Beautiful crystals 
 for the lapidary are brought from Minas Novas, in Brazil. 
 When cut with facets and set in rings, they are readily mis- 
 taken, if viewed by daylight, for diamonds. From their 
 peculiar limpidity, topaz pebbles are sometimes denomi- 
 nated gouttes @eau. 
 
 The perfect cleavage of topaz makes it a poor substitute 
 for emery. | 
 
 Euclase. 
 
 Monoclinic. In oblique rhombic prisms, with cleavage 
 highly perfect parallel to the clinodiagonal section, afford- 
 ing smooth polished faces. 
 
 Color pale green to white or colorless, pale blue. Lustre 
 vitreous; transparent. Brittle. H=7d. G.=3:1. Pyro- 
 electric. 
 
SUBSILICATES, 289 
 
 Composition. H,Be,Al 0, Si,= Silica 41°20, alumina 35:22, 
 glucina 17°39, water 6:19=100. B.B. fuses with much dif- 
 ficulty to a white enamel ; not acted on by acids. 
 
 Diff. The cleavage of this glassy mineral is, like that of 
 topaz, very perfect, but is not basal. The cleavage distin- 
 guishes it from tourmaline and beryl. 
 
 Obs. Occurs in the Ural, and with topaz in Brazil. 
 
 The crystals of this mineral are elegant gems of them- 
 selves, but they are seldom cut for jewelry on account of 
 their brittleness. . 
 
 Datolite.—Datholite. Humboldtite. 
 
 Monoclinic. Crystals without distinct cleavage; small 
 and glassy. Also botryoidal, 
 with a columnar structure, 
 and then called dotryolite. 
 Color white, occasionally gray- 
 ish, greenish, yellowish, or red- 
 dish. Translucent. H.=5-5°5. 
 Gi 2"8-3. 
 
 Composition. H,Ca,B, 01 Si, 
 =Silica 37°5, boron trioxide 
 21:9, lime 35°0, water 56= 
 100. Botryolite contains twice 
 the proportion of water. B.B. 
 becomes opaque, intumesces and melts easily to a glassy 
 globule coloring the flame green. Decomposed by hydro- 
 chloric acid ; the solution gelatinizes on evaporation. 
 
 Diff. Its glassy complex crystallizations, without cleavage, 
 are unlike any other mineral that gelatinizes with acid. 
 It is distinguished from minerals that it resembles also by 
 tingeing the blowpipe-flame green. 
 
 Obs. Occurs in cavities in trap rocks and gneiss. Found 
 in Scotland ; at Andreasburg; at Baveno; Toggiana; also 
 Bergen Hill, in N. J.; in Connecticut, at Roaring Brook, 
 14 miles from New Haven ; and near Hartford, Berlin, Mid- 
 dlefield Falls, Conn.; also in great abundance at Eagle 
 Harbor in the copper region, Lake Superior, and on Islo 
 Royale ; also near Santa Clara, Cal. 
 
 
 
 Hlomilite. A black silicate of iron and calcium, resembling gadoli- 
 nite, but affording from 15 to 18 per cent. of boracic acid with 82 of 
 silica; formula R,B, O,,8i,. From Brevig, Norway. 19 
 
290 DESCRIPTIONS OF MINERALS. 
 
 Titanite.—Sphene. 
 
 Monoclinic. In very oblique rhombic prisms ; the lateral 
 faces making angles often of 76° 7’, 113° 31' (IAL), 186° 12! 
 
 ar Qe 3. 
 
 | aes 
 
 (2A2), or 133° 52’. The crystals are usually thin with 
 sharp edges. Cleavage in one direction sometimes perfect. 
 Occasionally massive. 
 
 Color grayish-brown, ash-gray, brown to black; some- 
 times pale yellow to green ; streak uncolored. Lustre 
 adamantine to resinous. ‘Transparent to opaque. H. =5- 
 55. G.=3°2—-3°6. 
 
 Composition. CaTi0; Si—Silica 30°6, titanium dioxide 
 40°82, lime 28°57=100 ; in dark brown and black crystals, 
 some iron replaces part of the calcium. B.B. fuses with 
 ‘ntumescence. Imperfectly decomposed by hydrochloric 
 acid. 
 
 The dark varieties of this species were formerly called . 
 titanite, and the lighter sphene. The name sphene alludes 
 to the wedge-shaped crystals, and is from the Greek sphen, 
 wedge. Greenovite is a variety colored rose-red by manga- 
 nese. 
 
 Diff. The thin wedge-like form of the crystals, in general, 
 readily distinguish this species ; but some crystals are very 
 complex. 
 
 Obs. Sphene occurs mostly in disseminated crystals in 
 granite, gneiss, mica slate, syenyte, or granular limestone. 
 Tt is usually associated with pyroxene and scapolite, and 
 often with graphite. It has been found in voleanic rocks. 
 The crystals are commonly $ to $ an inch long; but are 
 sometimes 2 or more inches in length. 
 
 Foreign localities are Arendal in Norway ; at St. Gothard 
 and Mont Blanc; in Argyleshire and Galloway in Great 
 Britain. Occurs in Canada, at Grenville and elsewhere ; 
 New York, at Roger’s Rock, on Lake George ; with graphite 
 
SUBSILICATES. 291 
 
 and pyroxene, at Gouverneur, near Natural Bridge in Lewis 
 County (the variety called Lederite); in Orange County in 
 Monroe, Edenville, Warwick, and Amity ; near Peekskill in 
 Westchester County, and near West Farms ; In Massachu- 
 setts, at Lee, Bolton, and Pelham; in Connecticut, at Trum- 
 bull; in Maine, at Sanford, and Thomaston ; in New Jer- 
 sey, at Franklin ; in Pennsylvania, near Attleboro’, Bucks 
 County ; in Delaware, at Dixon’s quarry, 7 miles from 
 Wilmington ; in Maryland, 25 miles from Baltimore, on 
 the Gunpowder. 
 
 Guarinite. Like sphene in composition, but trimetric. 
 
 Keilhauite, or Yitro-titanite. Related to sphene. Brownish-black, 
 with a grayish-brown powder. G.=—3°69. H.—6'5. Fuses easily. 
 Affords Silica 30:0, titanic acid 29 0, yttria 9°6, lime 18°9, iron sesqui- 
 oxide 6-4, alumina 6-1. From Arendal, N orway. 
 
 Uscheffkinite. Near Keilhauite. From the Ilmen Mountains. 
 
 Staurolite.—Staurotide, 
 
 Trimetric. ZA I=129° 20’. Cleavage imperfect. Usual- 
 ly in cruciform twin crystals. Fig- 
 ure 18 is a common kind; another 
 crosses at an acute angle near 60° ; 
 and another, of rare occurrence, con- 
 sists of three crystals intersecting at 
 angles near 60°. Never in massive 
 forms or slender crystallizations. 
 
 Color dark brown or black. Lustre vitreous, inclining 
 to resinous ; sometimes bright, but often dull. Translu- 
 cent to opaque. H.=%-7'5. G.=3-4-3°8. 
 
 Composition. H,R;Al, Oy Sis=Silica 30°37, alumina 51°92, 
 iron protoxide 13°66, magnesia 2°53, water 152—100. B.B. 
 infusible. Insoluble in acids. . 
 
 Diff. Distinguished from tourmaline and garnet by its 
 infusibility and form. 
 
 _ Obs. Found in mica slate and gneiss, in imbedded crys- 
 tals. 
 
 Occurs very abundant through the mica schist of New 
 England : Franconia, Vt.; Windham, Me. ; Lisbon, N. H.; 
 Chesterfield, Mass.; Bolton and ‘Tolland, Ct.; also on the 
 Wichichon, eight miles from Philadelphia ; at Canton, and 
 in Fannin County, Georgia. Mt. Campione in Switzerland, 
 and the Greiner Mountain, Tyrol, are noted foreign locali- 
 ties. 
 
 
 
992 DESCRIPTIONS OF MINERALS. 
 
 The name staurolite is from the Greek stawros, a cross. 
 
 Schorlomite. Black, and often irised tarnished. Streak grayish-black. 
 H.—7-7'5. G.=8'80. Fuses readily on charcoal. Easily decomposed 
 by the acids, and gelatinizes. Contains much titanium, with iron, lime, 
 and silica, From Magnet Cove, Arkansas, and Kaiserstuhlgebirge, 
 Breisgau. 
 
 B. HYDROUS SILICATES. 
 
 The three sections under which the Hydrous Silicates 
 are arranged are the following : 
 
 I. Generat Section. Under this section there are in- 
 cluded: (1) Bisilicates—Pectolite, Laumontite, Apophy- 
 lite, etc. ; (2) Unisilicates—Prehnite, Calamine, ete. ; and 
 (3) Subsilicates—as Allophane, and some related species. 
 
 Il. Zeourre Section. The minerals included are feld- 
 spar-like in constituents, and apparently so in quantivalent 
 (or oxygen) ratio ; the basic elements being, as in the feld- 
 spars, (1) aluminum, and (2) the metals of the alkalis K, 
 Na, and of the alkaline earths Ca, Ba, with also Sr, to the 
 almost total exclusion of magnesium and iron. 
 
 tll. Marcarorpnyiiite Section. This section em- 
 braces species having a micaceous or thin-foliated struc- 
 ture when crystallized, with the surface of the folia pearly, 
 and the plane angle of the base of the prism 120°. Whether 
 crystallized or massive the feel is greasy, at least when 
 pulverized. It comprises (1) Bisilicates : including Tale and 
 Pyrophyllite, which are atomically and physically similar 
 species, although the former is a magnesium silicate, and 
 the latter an’ aluminum silicate; (?) Non-alkaline Uni- 
 silicates, including Kaolinite and Serpentine, which have a 
 similar difference in constituents to the preceding with 
 the same likeness in composition, and also some related 
 species ; (3) Alkaline Unisilicates : as, Pinite and the Hy- 
 drous Micas, which are species containing potassium or 
 sodium as an essential constituent ; (4) the Chlorite Group, 
 the species of which are mostly Subsilicates. 
 
HYDROUS SILICATES—GENERAL SECTION. 293 
 
 I. GENERAL SECTION, 
 Pectolite. 
 
 - Monoclinic, isomorphous with wollastonite. Usually in 
 aggregations of acicular crystals, or fibrous-massive, radiate, 
 stellate. Color white, or grayish. ‘Translucent to opaque. 
 Tough. H.=5. G.=2°68-2°8. 
 
 Composition. RO; Si, in which R=4H, t{Na, §Ca, = Silica 
 54:2, lime 33°8, soda 9°3, water 2°7=100. In the closed 
 tube yields water. B.B. easily fusible. Decomposed by hydro- 
 chloric acid, and the solution gelatinizes somewhat when 
 evaporated. 
 
 Diff. Its fibrous forms and its blowpipe reactions are 
 distinctive. 
 
 Obs. Occurs mostly in cavities or seams in trap or basic 
 eruptive rocks, and occasionally in other rocks. Found 
 at Ratho Quarry, near Edinburgh, Scotland; at Kilsyth ; 
 Isle of Skye ; in the Tyrol; in fine specimens at Bergen 
 Hill, N. J.; a compact variety at Isle Royale, Lake Supe- 
 rior. 
 
 Okentte and Gyrolite aye related hydrous calcium silicates. Okenite 
 is from the Faroe Islands, Iceland, and Greenland, and gyrolite from 
 the Isle of Skye, and from Nova Scotia 25 miles southwest of Cape 
 Blomidon. 
 
 Cymatolite. White, curved-fibrous (to which the name from the 
 Greek kuma, wave, alludes), vitreo-pearly, with G.=2°74. Analysis 
 afforded Silica 61:21, alumina 28°01, potassium 4°54, water 3°83, with 
 about half a per cent. each of lime, soda, and lithia, making ita hydrous 
 bisilicate, if half the water be made basic. Derived trom the altera- 
 tion of spodumene. Occurs at Goshen and N orwich, Mass., and Red- 
 ding, Conn. At the latter place crystals of spodumene of great size 
 are converted into it. 
 
 Laumontite. 
 
 Monoclinic, with the angles nearly of pyroxene ; JA J= 
 86° 16’. Cleavage parallel to the clinodiagonal section and 
 to I perfect. Also massive, with a radiating or divergent 
 structure. 
 
 Color white, passing into yellow or gray, sometimes red. 
 Lustre vitreous, inclining to pearly on the cleavage face. 
 Transparent to translucent. H.=3:5-4. G.=2°25-2°36. 
 Becomes opaque on exposure through loss of water, and 
 readily crumbles. 
 
 Composition. OaAl0,S8i+4aq=Silica 50:0, alumina 
 21°8, lime 11:9, water 16°3=100. B.B. swells up and fuses 
 
994 DESCRIPTIONS OF MINERALS. 
 
 easily to a white enamel. Decomposed by hydrochloric acid, 
 and the solution gelatinizes on evaporation. 
 
 Diff. The alteration this species undergoes on exposure 
 to the air at once distinguishes it. This result may be 
 prevented with cabinet specimens, by dipping them into a 
 solution of gum arabic. 
 
 Obs. Found in the veins and cavities of trap rocks and 
 also in gneiss, porphyry. Occurs at the Faroe Islands ; Kil- 
 patrick Hills, near Glasgow ; Disko, Greenland ; St. Goth- 
 ard, Switzerland ; Peter’s Point, Nova Scotia; Phippsburg, 
 Me.; Charlestown syenite quarries, Mass. ; Bergen Hill, 
 N. J.; the Copper region, Lake Superior, and Isle Royale. _ 
 
 Apophyllite. 
 
 Dimetric. In square octahedrons, prisms, and tables. 
 Cleavage parallel with the base highly perfect. Massive 
 
 
 
 and foliated. Color white or grayish ; sometimes with a 
 shade of green, yellow, or red. Lustre of O pearly: of the 
 other faces vitreous. ‘Transparent to opaque. U.=4°5-0. 
 G. = 2'3-2°4. 
 
 Composition. A silicate of calcium and hydrogen com- 
 bined, with potassium fluoride and water, of the formula 
 (4H, $Ca) O, Si + {KF + daq=Silica 52°97, lime 24°72, 
 potash 5-20, water 15:90, fluorine 2-10=100°89. B.B. exfo- 
 liates, colors the flame violet (owing to the potash), and 
 fuses very easily to a white enamel, In the closed tube 
 yields water which has an acid reaction. Decomposed by 
 hydrochloric acid with the separation of slimy silica, 
 
HYDROUS SILICATES—GENERAL SECTION. AUD 
 
 Diff. The pearly basal cleavage and the forms of its glassy 
 crystals at once distinguish it from the preceding species. 
 The prisms are sometimes almost cubes, with the angles 
 cut off by the planes of the pyramid ; but the difference in 
 the lustre of the prismatic and basal faces shows that it 
 is dimetric. : 
 
 The name alludes to its exfoliation before the blowpipe. 
 
 Obs. Found in amygdaloidal trap and basalt. 
 
 Occurs in fine crystallizations at Peter’s Point and Par- 
 _tridge Island, Nova Scotia, at Bergen Hill, N. J., the Chiff 
 Mine, Lake Superior region. 
 
 Catapleiite. A hydrous zirconium and sodium silicate, from Nor- 
 way. 
 
 ee and Ohrysocolla. ydrous copper silicates. See p. 141. 
 
 Picrosmine, Pyrallolite, Picrophyll, Traverseliite, Pitkarandite, Stra- 
 konitzite, Monradite, are names of varieties of pyroxene in different 
 stages of alteration. Xvylotine is probably altered asbestus. 
 
 Prehnite. 
 
 Trimetric. ZAT=99° 56’. Cleavage basal. Sometimes 
 in six-sided prisms, rounded so as to be barrel-shaped, and 
 composed of a series of united plates ; also in thin rhom- 
 bic or hexagonal plates. Usually reniform and botryoidal, 
 with a crystalline surface ; texture compact. . 
 
 Color light green to colorless. Lustre vitreous, except 
 the face 0, which is somewhat pearly. Subtransparent to 
 translucent. H.=6-6:5. G.=2-8~2°96. 
 
 Composition. H,Ca,Al0O,,.8i,=Silica 43°6, alumina 24:9, 
 lime 27:1, water 44=100. 3B.B. fuses very easily to an en- 
 amel-like glass. Decomposed by hydrochloric acid, leaving 
 a residue of silica in lght flakes, but the solution does not 
 gelatinize. Yields a little water when heated in a closed 
 tube. 
 
 Diff. Distinguished from beryl, green quartz, and chal- 
 cedony by fusing before the blowpipe, and from the zeolites 
 by its superior hardness. 
 
 Obs. Found in the cavities of trap, gneiss, and granite. 
 
 Occurs in the trap rocks of the Connecticut Valley, and 
 at Paterson and Bergen Hill, N. J.; in gneiss at Bellows 
 Falls, Vt.; in syenyte at Charlestown, Mass.; and very 
 abundant, forming large veins, in the Copper region of Lake 
 Superior, three miles south of Cat Harbor, and elsewhere. 
 
 The Fassa Valley in the Tyrol, St. Christophe in Dau- 
 
 53 
 
oe 
 
 296 DESCRIPTIONS OF MINERALS. 
 
 phiny, and the Salisbury Crag, near Edinburgh, are some 
 of the foreign localities. 
 
 Prehnite receives a handsome polish and is sometimes 
 used for inlaid work. In China it is polished for orna- 
 ments, and large slabs have been cut from masses brought 
 from there. 
 
 Chlorastrolite and Zonochlorite, from the Lake Superior region, are 
 impure prehnite. 
 
 Chalcomorphite. A hydrous calcium silicate, from calcite in cavities 
 of lava, containing but 25°4 per cent. of silica. 
 
 Gismondite (Zeagonite). A hydrous lime-aluminum silicate, occur- 
 ring in trimetric crystals resembling square octahedrons ; found in 
 lava at Capo di Bove, near Rome. 
 
 Edingtonite. A hydrous barium-aluminum silicate. Occurring in 
 crystals and massive. From the Kilpatrick Hills, with harmotome. 
 
 Carpholite. A manganese-aluminum silicate, occurring in silky, 
 yellow, radiated tufts. From the tin mines of Schlackenwald. 
 
 Pyrosmalite. A manganese-iron silicate and chloride, from Sweden. 
 
 Calamine. A hydrous zinc unisilicate. See p. 107. 
 
 Villarsite. Probably altered chrysolite. 
 
 Cerite, Tritomite, Erdmannite, are cerium and lanthanum silicates. 
 
 Thorite (Orangite) and Lucrasite, are thorium silicates; the latter 
 hydrous. 
 
 Allophane. 
 
 In amorphous incrustations, with a smooth small-mam- 
 millary surface, and often hyalite-like, and sometimes pul- 
 verulent. Color pale bluish-white to greenish-white, and 
 deep green; also brown, yellow, colorless. ‘Translucent. 
 Div3 ane reoSieeu: 
 
 Composition. Mostly AlO; Si+6 (or 5) aq. Silica 23°75, 
 alumina 40°62, water 35°63=100. In the closed tube yields 
 much water. B.B. infusible, but crumbles. A blue color 
 with cobalt solution, and a jelly with hydrochloric acid. 
 
 Occurs in Saxony; at the Chessy Copper Mine near 
 Lyons; at a copper mine in Bohemia; with limonite in 
 Moravia ; in Old Chalk Pits near Woolwich, England ; with 
 gibbsite in limonite beds in Richmond, Mass.; at the cop- 
 per mine of Bristol, Conn.; at Morgantown, Pa. ; copper 
 mines of Polk County, Tenn. 
 
 
 
 Collyrite. A hydrous aluminum silicate containing only 14 to 15 per 
 cent. of silica, and 35 to 40 of water ; and Schrétterite is another with 
 11 to 12 per cent. of silica. The latter has been reported as occurring, 
 as a gum-like incrustation, at the falls of Little River, on Sand Moun- 
 tain, Cherokee County, Alabama, Scarbroite is a related mineral 
 of doubtful nature, 
 
HYDROUS SILICATES—ZEOLITE SECTION. 29% 
 
 II. ZEOLITE SECTION. 
 
 The species of the Zeolite Section have been described as 
 having some relation to the feldspars in constitution. In 
 the feldspars, as explained on page 273, the following ratios, 
 for the protoxides, alumina, and silica which analyses af- 
 ea 45 6, 12338, 15379, 1:3;10, 1:3: 12. 
 So, among the zeolites, if the water be left out of considera- 
 tion, these are the ratios: 1:3:4 (in Thomsonite), 1:3:6 
 (Natrolite, Scolecite, etc.), 1:3:8 (Analcite, Chabazite, 
 etc.), 1:3:10 (Harmotome), 1:38:12 (Stilbite, Heulandite, 
 etc.). This fact, added to the absence or nearly total ab- 
 sence of magnesium and iron, and presence instead of Na,, 
 K,, Ca, Ba, make out a distinct relation to the feldspars, 
 whatever may be the part which the water sustains in the 
 compounds. Besides barium, strontium is sometimes pres- 
 ent, an element not yet known to characterize a species of 
 feldspar. | 
 
 These minerals were called zeolites because they generally 
 fuse easily with intumescence before the blowpipe, the term 
 being derived from the Greek zeo, to boil. Among those 
 described beyond, Heulandite and Stilbite, have a strong 
 pearly cleavage, and the latter is often in pearly radiations ; 
 Natrolite, Scolecite, are fibrous and radiated, or in very 
 slender prisms ; Thomsonite occurs either radiated, or com- 
 pact, or in short crystals ; while Harmotome, Analcite, and 
 Chabazite, and the related Gmelinite, occur only in short 
 or stout glassy crystals, those of chabazite looking some- 
 times like cubes. 
 
 The zeolites are sometimes called ¢rap minerals, because 
 they are often found in the cavities or fissures of amygda- 
 loidal trap as well as related basic eruptive rocks. Yet 
 they occur also occasionally in fissures or cavities in gneiss, 
 granite, and other metamorphic rocks. ‘I'hey are not the 
 original minerals of any of these rocks; but the results of 
 alteration of portions of them near the little cavities or fis- 
 
298 DESCRIPTIONS OF MINERALS, 
 
 sures in which the mincrals occur ; and part were made 
 while the rock was still hot, and as cooling went forward. 
 Besides true zeolites, such cavities often contain also 
 Laumontite (p. 293), noted for its tendency to crumble 
 on exposure; Pectolite and Okenite (p. 293), which are 
 fibrous like Natrolite and Scolecite ; Apophyllite (p. 294), 
 having one pearly cleavage like heulandite -and stilbite 5 
 Prehnite (p. 295), usually apple-green ; Datolite (p. 289), 
 in stoutish glassy complex crystals, or in smooth botryoidal 
 forms ; Aragonite (p. 218), sometimes radiated fibrous, and 
 Calcite (p. 215) with its three directions of like easy cleav- 
 age, both effervescing with hydrochloric acid; Siderite 
 (p. 185), in spheroidal or other forms; Chlorite (p. 316), 
 of dark olive-green color ; and Quartz, either in crystals, 
 or as chalcedony, agate, or carnelian, and in either case 
 easily distinguished by the hardness, absence of cleavage, 
 and infusibility. Of all these species Calcite and Quartz 
 are the most common. Of rarer occurrence than the above, 
 there are Orthoclase, Asphaltic coal, Copper, ete. 
 
 All the zeolites yield water in the closed tube, and many 
 of them gelatinize with hydrochloric acid. / 
 
 Thomsonite. 
 
 Trimetric. In right rectangular prisms. Usually in 
 masses having a radiated structure within, and consisting 
 of long fibres, or acicular crystals ; also amorphous. 
 
 Color snow-white ; impure varieties brown. Lustre vi- 
 treous, inclining to pearly. ‘Transparent to translucent. 
 H.=5—5, Brittle. GF. = 2°3-2°4. 
 
 Composition. (Ca,Nae)Al Os Sip +25 aq= Silica 38°09, al- 
 umina 31°62, lime 12°60, soda 4°62, water 13°40=100°20. 
 
 B.B. fuses very easily to a white enamel. Decomposed by 
 hydrochloric acid; the solution gelatinizes when evaporated. 
 
 Diff. Distinguished from natrolite by its fusion to an 
 opaque and not to a glassy globule. | 
 
 Obs. Occurs in amygdaloid, near Kilpatrick, Scotland ; 
 in lavas at Vesuvius, Comptonite; in clinkstone in Bohemia; 
 the Tyrol, etc.; at Peter’s Point, Nova Scotia, in trap; @ 
 massive variety, called Ozarkite, at Magnet Cove, Ark. 
 
HYDROUS SILICATES—ZEOLITE SECTION, 999 
 
 The species was named after Dr. Thomas Thomson, of 
 Glasgow. 
 Natrolite. 
 
 Trimetric. In slender prisms, terminated by a short pyra- 
 mid; /AJ=91°; 1A1 over 7=1438° 20’. Also 
 in globular, stellated, and divergent groups, 
 consisting of delicate acicular fibres, the 
 fibres often terminating in acicular prismatic 
 
 crystals. 
 Color white, or inclining to yellow, gray, 
 or red. Lustre vitreous. ‘Transparent to 
 translucent. H.=5-5'5. G.=2*17-2°25. 
 Brittle. 
 
 Composition. NasAl Oy Si, +2 aq = Silica 
 47°29, alumina 26°06, soda 16°30, water 
 9°45=100. B.B. fuses easily and quietly to a clear glass ; 
 a fine splinter melts in a candle flame. Decomposed by hy- 
 drochloric acid, and the solution gelatinizes on evaporation. 
 
 Diff. Distinguished from scolecite by its quict fusion. 
 
 Obs. Found in amygdaloidal trap, basalt and volcanic 
 rocks; sometimes in seams in granitic rocks. ‘The name 
 natrolite is from natron, soda. 
 
 Occurs in Bohemia; Auvergne; Fassathal, Tyrol; at Glen 
 Farg in Fifeshire; in Dumbartonshire ; Nova Scotia ; Ber- 
 gen Hill, N. J. 
 
 Scolecite. Resembles natrolite, and differs in containing lime in place 
 of soda; also in having its slender rhombic glassy prisms longitudi- 
 nally twinned, as is shown by the meeting of two ranges of striz at an 
 angle along or near the central line of opposite prismatic planes. The 
 lustre is vitreous or a little pearly. B.B. it curls up like a worm 
 (whence the name from the Greek skolew, a worm) and then melts. 
 From Staffa, Iceland, Finland, Hindostan. 
 
 Mesolite. Another related species. 
 
 
 
 Analcite. 
 
 Dimetric or Trimetric. Occurs usually in trapezohedron 
 (fig. 1, also fig. 2). 
 
 The appearance sometimes 
 seen in polarized light is 
 shown in figure 7, page 69. 
 On account of this peculiar 
 behavior and indications of 
 a compound structure ob- 
 tained in a microscopic study 
 
 
 
300 DESCRIPTIONS OF MINERALS. 
 
 of thin slices, it has been suspected to be dimetric like 
 leucite, or else trimetric like phillipsite, although the forms 
 of the crystals are apparently isometric. Often colorless 
 and transparent, also milk-white, grayish and reddish- 
 white, and sometimes opaque. Lustre vitreous. H.=5-5'5. 
 (G2 20: 
 
 Composition. NagAl O.».Siz+2aq = Silica 5447, alumina 
 23-29, soda 14:07, water 8°17=100. B.B. fuses easily to a 
 colorless glass. Decomposed by hydrochloric acid ; and the 
 silica separates in gelatinous lumps. 
 
 Diff. Characterized by its crystallization, without cleav- 
 age. Distinguished from quartz and leucite by giving water 
 in a closed glass tube; from calcite by its fusibility, and by 
 not effervescing with acids; from chabazite and its varieties 
 by fusing without intumescence to a glassy globule, and by 
 the crystalline form. 
 
 Obs. Found in cavities and seams in amygdaloidal trap, 
 basalt and other eruptive rocks, and sometimes in granite, 
 syenyte and gneiss. 
 
 Oécurs in fine crystallizations in Nova Scotia; also at 
 Bergen Hill, N. J.; Perry, Me.; and in the trap of the Cop- 
 per region, Lake Superior. The Faroe Islands, Iceland ; 
 Glen Farg, near Edinburgh ; Kilmalcolm, the Campsie 
 Hills, and Antrim ; the Vicentine; the Hartz at Andreas- 
 berg ; Sicily, and Vesuvius, are some of the foreign localities. 
 
 The name analcite is from the Greek, analkis, weak, al- 
 luding to its weak electric power when heated or rubbed. 
 
 Eudnophite. Near analcite. From Norway. 
 Faujasite. In isometric octahedrons. From the Kaiserstuhl, Baden. 
 
 Chabazite. 
 
 Rhombohedral. Often in rhombohedrons, much resem- 
 bling cubes. BR: R=94° 46’. Cleavage parallel to 
 
 . Rk. Also in complex modifications of this form. 
 eR Never massive or fibrous. 
 Color white, also yellowish, and flesh-red or red. 
 Lustre vitreous. ‘Transparent to translucent. H.= 
 4-5, G.=2°08—2:19. 
 The red chabazite of Nova Scotia has been called Acadi- 
 alite. 
 Composition. CaAl O,, Sig + 6aq, with a little Na, or K, in 
 place of part of the Ca. ‘The Nova Scotia acadialite afforded 
 
HYDROVUS SILICATES—ZEOLITE SECTION, 801 
 
 Silica 52:20, alumina 18°27, lime 6°58, soda and potash 2°12, 
 water 20°52. B.B. intumesces and fuses to a nearly opaque 
 bead. Decomposed by hydrochloric acid, with the separa- 
 tion of slimy silica. In the closed tube gives water. Phac- 
 olite is a variety in complex glassy crystals. 
 
 Diff. Vhe nearly cubical form often presented by the 
 crystals of chabazite is a striking character. It is distin- 
 guished from analcite as stated under that species; from 
 calcite by its hardness and action with acids ; from fluorite 
 by its form and cleavage, and its showing no phosphores- 
 cence. 
 
 Obs. Found in trap and occasionally in gneiss, syenyte, 
 and other rocks. Chabazite is met with in the trap of Con- 
 necticut Valley, but in poor specimens; also at Hadlyme 
 and Stonington, Conn.; Charlestown, Mass.; Bergen Hill, 
 N. J.; Piermont, N. Y.; Jones’s Falls, near Baltimore 
 (Haydenite). Nova Scotia affords common chabazite, and 
 also the acadialite in abundance. The Faroe Islands, Ice- 
 land, and Giant’s Causeway, are some of the foreign locali- 
 ties; also the County of Antrim, Ireland. 
 
 Herschelite. Near chabazite, if not identical with it. From Sicily. 
 
 Gmelinite. Closely resembles some chabazite, but its crystals are 
 usually hexagonal rather than rhombohedral in appearance. Formula 
 (Naz,Ca)Als 0, Sis. A Bergen Hill specimen afforded Silica 4867, alu- 
 mina 18°72, lime 2°60, soda 9°14, water 21°35=100°48. Gelatinizes with 
 hydrochloric acid, but in other respects resembles chabazite. Occurs 
 at Andreasberg ; in Antrim, Ireland ; in Skye; at Bergen Hill, Nodes 
 in Nova Scotia at Cape Blomidon. Named after the chemist, Gmelin. 
 
 Levynite (Levyne). Rhombohedral, and somewhat resembling gme- 
 linite in its crystals; excluding the water, having the quantivalent 
 ratio of labradorite, 1: 3:6. Colorless, white, grayish, reddish. From 
 Iceland, Greenland, Antrim, Londonderry, Hartfield Moss near Glas- 
 gow, Named after the crystallographer, Lévy. 
 
 Harmotome. 
 
 Monoclinic. Unknown except in compound crystals; and 
 commonly in forms similar to the annexed figure ; also in 
 compound rhombic prisms. 
 
 Color white ; sometimes gray, yellow, red, or brownish. 
 eens to translucent. Lustre vitreous. H.=4°5. 
 
 pene 45. 
 
 Composition. BaAl 0,,8i;+5 aq=Silica 46:5, alumina 15°9, 
 baryta 23°7, water 13:°9=100; but a little of the baryta re- 
 placed by potash. B.B. whitens, crumbles, and fuses quietly 
 
302 DESCRIPTIONS OF MINERALS, 
 
 to a white translucent glass. Gives water in a closed glass 
 tube. Partially decomposed by hydrochloric acid, and if 
 sulphuric acid be added to the solution, 
 a heavy white precipitate of barium sul- 
 phate is formed. Some. varieties phos- 
 
 horesce when heated. 
 
 Diff. Its twin crystals, when distinct, 
 cannot be mistaken for any other species 
 except phillipsite. Much more fusible 
 than glassy feldspar or scapolite; does 
 
 not gelatinize in acids like thomsonite. 
 Obs. Occurs in amygdaloidal trap, 
 and in trachyte and phonolyte, also in 
 
 gneiss, and metalliferous veins. Fine 
 crystallizations are found at Strontian in Scotland, and 
 in’ Dumbartonshire; Andreasberg in the Hartz; Kongs- 
 berg in Norway. Has been found in seams in the gneiss 
 of the upper part of New York Island. 
 
 The name harmotome is from the Greek harmos, a joint, 
 and temno, to cleave. 
 
 Phillipsite. Near harmotome in its cruciform crystals and 
 other characters ; but differing in containing lime in place 
 of baryta. It differs also in gelatinizing with acids and in 
 fusing with some intumescence. It also occurs in sheaf-like 
 aggregations and in radiated crystallizations. From the 
 - Giant’s Causeway, Capo di Boye, Vesuvius, Sicily, Iceland. 
 
 Epistilbite. A hydrous silicate of alumina and lime. Occurs in 
 thin rhombic prisms, of a white color, with a perfect pearly cleavage 
 like stilbite. H.—4-4'5. G.—2°25. Before the blowpipe froths and 
 forms a vesicular enamel. Does not gelatinize. From Iceland and 
 Hindostan, and sparingly at Bergen Hill, N. J. 
 
 Bravaisite. Supposed to be a zeolite ; it has potassium, magnesium 
 and iron as the protoxide bases. 
 
 Stilbite. 
 
 In pyramidally terminated rectangular prisms usually 
 flattened parallel to the face 7-2, which is the 
 direction of cleavage and is very pearly in lustre. 
 1A1=119° 16’, and 114°. Also in sheaf-like ag- 
 gregations, and thin lamellar and columnar ; also 
 in pearly radiated crystallizations. 
 
 Color white ; sometimes yellow, brown or red. 
 Subtransparent to translucent. H.=3-4. Oa 
 21-215. ~ 
 
 
 
HYDROUS SILICATES—SEOLITE SECTION. 303 
 
 Composition. CaAl O,,Si,+ 6 aq=Silica 57:4, alumina 16°5, 
 lime 8:9, water 17°2=100; but with a httle Na,or K,in 
 place of part of the Ca B.B. exfoliates, swells up, and 
 curves into fan-like forms, and fuses to a white enamel. 
 Decomposed by hydrochloric acid without gelatinizing. 
 
 Diff. It cannot be scratched with the thumb-nail, like 
 Aas It is distinguished from heulandite by its crys- 
 tals. 
 
 Obs. Occurs mostly in trap-rocks; also on gneiss and 
 granite. Found on the Faroe Ids. ; Isle of Skye ; Isle of Ar- 
 ran, and elsewhere, Scotland ; Andreasberg, Hartz ; the Ven- 
 dayah Mts., Hindostan. Found sparingly at the Chester 
 and Charlestown syenite quarries, Mass.; at New Haven, 
 Thatchersville and Hadlyme, Conn., and other points in the 
 Connecticut Valley trap ; at Phillipstown, N. Y.; at Bergen 
 Hill, N. J.; in trap, in the copper region of Lake Superior ; 
 in beautiful crystallizations at various points in Nova 
 Scotia. 
 
 The name stilbite is derived from the Greek s?z/bé lustre. 
 It has also been called desmine, and in Germany heulandite, 
 where heulandite has been called s¢ilbite. 
 
 Heulandite. 
 
 Monoclinic. In right rhomboidal prisms like the figure, 
 with perfect pearly cleavage parallel to P and other 
 planes vitreous in lustre. P on M or T=90° ; M on TI’ 
 =129° 40’. Color white ; sometimes reddish, gray, 
 brown. ‘Transparent to subtranslucent. Folia brit- 
 tle. H.=3°5-4. G.=2:17-2:°2. 
 
 Composition. CaAlO,S8i,+5 aq=Silica 59:1, alu- 
 mina 16°9, lime 9°22, water 14°8=100. Contains 
 1 to 2 per cent. of Na, or K, in place of part of the 
 Ca. Blowpipe characters like those of stilbite. in- 
 tumesces and fuses, and becomes phosphorescent. Dis- 
 solves in acid without gelatinizing. 
 
 Diff. The very pearly lustre of the cleavage face is a 
 marked characteristic. Distinguished from gypsum by its 
 hardness ; from apophyllite and stilbite by its crystals ; and 
 from the latter species also in not occurring in radiated 
 crystallizations. 
 
 Obs. Found in amygdaloidal cavities and fissures in 
 trap ; occasionally in gneiss, and in some metalliferous 
 
804 DESCRIPTIONS OF MINERALS. 
 
 veins; in large crystallizations at Berufiord, Iceland ; 
 and Vendayah Mts., Hindostan; also at Isle Skye ; near 
 Glasgow ; Fassa Valley ; at Bergen Hill, N. J., in trap ; at 
 Hadlyme, Conn., and Chester, Massachusetts, on gneiss ; 
 near Baltimore, on a syenitic schist (Beawmontite) ; at 
 Peter’s Point and Cape Blomidon, and other places in 
 Nova Scotia, in trap. 
 
 The species was named by Brooke after Mr. Heuland, 
 of London. 
 
 Breusterite. Crystals monoclinic with a perfect pearly cleavage 
 like heulandite ; but M:T=93° 40’. H.=45-5. G.=2°'45. The for- 
 mula is analogous to that of heulandite, but baryta and strontia take 
 the place of the lime and soda. 
 
 Epistilbite. Composition like that of beulandite, but occurs in short 
 and very obtuse rhombic prisms, (JA [=185° 10’), at Skye ; the Faroe 
 Ids., in Iceland ; at Margaretville, in Nova Scotia. 
 
 Mordenite. Fibrous mineral from Morden, Nova Scotia. 
 
 Pilinite. Im slender needles, from Silesia. 
 
 ‘ Foresite. Near stilbite. From Elba. 
 
 Ill MARGAROPHYLLITE SECTION. 
 Talc. 
 
 Trimetric. In right rhombic or hexagonal prisms. IAI 
 —120°. Usually in pearly foliated masses, separating easily 
 into thin translucent folia. Sometimes stellate, or diver- 
 gent, consisting of radiating lamine. Often massive, con- 
 sisting of minute pearly scales ; also crystalline granular, or 
 of a fine impalpable texture. y 
 
 Lustre eminently pearly, and feel unctuous. Color some 
 shade of light green or greenish white ; occasionally silvery 
 white; also grayish green and dark olive-green. Hassde 
 1:5; easily impressed with the nail. G.=2°5-2'8. Lam- 
 inex flexible, but not elastic. 
 
 There are the following varieties : 
 
 Foliated Talc. The pure foliated tale, of a white or 
 greenish-white color. 
 
 Soapstone or Steatite. Gray or grayish green, and either 
 massive, crystalline granular, or impalpable ; very greasy to 
 the touch. French chalk is a milk-white variety, with a 
 pearly lustre. Potstone or Lapis Ollaris is impure soap- 
 stone of grayish-green and dark-green colors, and slaty | 
 structure, 
 
HYDROUS SILICATES—MARGAROPHYLLITE SECTION. 805 
 
 Indurated Tale, is a slaty talc, of compact texture, and 
 above the usual hardness, owing to impurities. 
 
 Rensselaerite. A compact crypto-crystalline rock, from 
 St. Lawrence and Jefferson counties, N.Y., of white, yellow, 
 or grayish-white colors, and even black. It has sometimes 
 the form and cleavage of pyroxene, and is in part at least a 
 product of the alteration of that mineral. 
 
 Composition. 4H, 4Mg O,Si=Silica 628, magnesia 33:5, 
 water 3°7=100. It usually contains a little iron replacing 
 magnesium. B.B. infusible. Moistened with cobalt nitrate 
 assumes a pink tint. Not acted upon by hydrochloric acid. 
 In closed tube gives a little water, but not till highly 
 heated. 
 
 Diff. The softness, unctuous feel, foliated structure, when 
 crystallized, and pearly lustre of tale are good characteris- 
 tics. It differs from mica also in being inelastic, although 
 flexible ; from chlorite, kaolinite, and serpentine in yielding 
 little water when heated in a glass tube. Only the massive 
 varieties resemble the last-mentioned species, and chlorite 
 has a dark olive-green color. Pyrophyllite, which cannot be 
 distinguished in some of. its varieties from talc, becomes 
 dark blue when moistened with cobalt nitrate and ignited. 
 
 Vbs. Occurs in Cornwall, near Lizard Point ; at Portsoy 
 in Scotland; at Croky Head, Ireland; in the Greiner 
 Mountain, Saltzburg. Handsome foliated tale occurs at 
 Bridgewater, Vt.; Smithfield, R. I. ; Dexter, Me.; Lock- 
 wood, Newton and Sparta, N. J.,and Amity, N. Y. On 
 Staten Island, near the Quarantine, both the common and 
 indurated are obtained ; at Cooptown, Md., green, blue, 
 and rose-colored tale occur. Steatite or soapstone is abun- 
 dant, and is quarried at Grafton, Vt. and an adjacent 
 town; at Francestown and Orford, N. H. It also occurs 
 at Keene and Richmond, N. H.; at Marlboro’ and New 
 Fane, Vt. ; at Middlefield, Mass. ; in Loudon County, Va., 
 and at many other places. 
 
 Steatite may be sawn into slabs and turned in a lathe. It 
 is used for firestones in furnaces and stoves, and fire-places. 
 It receives a polish after being heated, and has then a deep 
 olive-green color. ‘The finer kinds are made into images in 
 China, and into inkstands and other forms in other coun- 
 tries. Potstone is worked into vessels for culinary pur- 
 posesin Lombardy. The harder kinds are cut into gas jets. 
 Steatite is alsoused in the manufacture of poreslainss ib 
 
806 DESCRIPTIONS OF MTNERALS. 
 
 makes the biscuit semi-transparent, but brittle and apt to 
 break with slight changes of heat. It forms a polishing 
 material for serpentine, alabaster and glass. ‘‘ French 
 chalk” is used for removing grease-spots from cloth, as 
 well as for tracing on cloth. When ground up, soapstone 
 is employed for diminishing the friction of machinery. 
 
 Pyrophyllite-Agalmatolite, in part. 
 
 ‘Near tale in crystallization, cleavage, its occurrence in 
 fine-grained massive forms, its greasy feel, its white to pale- 
 green colors, varying to yellowish, its feeble degree of hard- 
 ness (1-2). The folia are sometimes radiated. G.=2'75- 
 a Ons 
 
 Composition. An aluminous bisilicate, instead of a mag- 
 nesian, for the most part of the formula, AlO,8i, ‘The 
 Chesterficld, 8S. C., mineral afforded Genth, Silica 6482, 
 alumina 24°48, iron sesquioxide 0:96, magnesia 0°33, lime 
 0-55, water 5°25=100°39. B.B. whitens and fuses with dif- 
 ficulty on the edges. Gives a deep blue color with cobalt 
 solution. Yields water in the closed tube. Radiated varie- 
 ties exfoliate in fan-like forms. 
 
 Obs. Compact pyrophyllite is the chief constituent of a 
 kind of slate or schist, which is used for slate pencils, and 
 hence is called pencil-stone. Occurs in the Urals ; at Wes- 
 ‘tana in Sweden; in Elfdalen, with cyanite ; foliated, in 
 North Carolina, in Cottonstone Mountain ; in South Caro- 
 lina, in Chesterfield District, with lazulite and cyanite ; 
 Georgia, in Lincoln County, on Graves Mountain ; in Ar- 
 kansas, near Little Rock ; compact slaty in the Deep River 
 region, N. C., and at Carbonton, Moore County, N. C. 
 
 Sepiolite—Meerschaum of the Germans. 
 
 Usually compact, of a fine earthy texture, with a smooth 
 feel, and white or whitish color ; also fibrous, white to bluish- 
 green in color, H.=2-20. The earthy variety floats on 
 water. 
 
 Composition. 4H,3Mg 0, 8i+1;aq= Silica 60°8, magnesia 
 ou-1, water 12°1=100. B.B. infusible, or fuses with great 
 difficulty on the thin edges. Much water in a closed tube. 
 A pink color with cobalt solution. ° 
 
 Occurs in Asia Minor in masses in stratified earthy de- 
 posits, and is extensively used for pipe bowls ; also found in 
 
-HYDROUS SILICATES—MARGAROPHYLLITE SECTION, 307 
 
 Greece, Moravia, Spain, etc. ; also in fibrous scams at a sil- 
 ver mine in Utah. 
 
 Aphrodite. Similar to the preceding. MgOs:Si+3H. From Swe- 
 den. Cimolite, a clay from the Island of Argentiera, Kimole of the 
 Greeks. Smectite, a kind of ‘‘ Fuller’s Earth,” a name given to unc- 
 tuous clays used in fulling cloth. Montmorillonite, Stolpenite, and 
 Steargillite, are related clay-like minerals. 
 
 Glauconite.—Green Earth. 
 
 In dark olive-green to yellowish-green grains, or granular 
 masses, with dull lustre. H.=2. G.=2°2-2:4, 
 
 Composition. Essentially a silicate of iron and potassium. 
 Formula RR O,.S8i,, in which R is mainly Fe and K, with 
 sometimes Mg ; andRis Al, but sometimes largely Ee. Analy- 
 ses give mostly 50-58 per cent. silica, 20-24 iron protoxide, 
 4-12 of potash and 8-12 of water. B.B. fuses easily to a 
 magnetic glass. Yields water in a closed tube. 
 
 Obs. In a more or less pure state it forms thick beds in 
 the Cretaceous formation, and also in the Lower Tertiary 
 of New Jersey ; also occurs in other older rock formations 
 down to the Lower Silurian. Found also, first by Pour- 
 tales, in the pores of corals and cavities of Rhizopod shells 
 over the existing sea-bottom, showing it to be a marine 
 product, and one now in progress of formation. The grains 
 of the Cretaceous, Tertiary, and Lower Silurian beds have 
 been shown by Ehrenberg to be the casts of the interior of 
 shells of Rhizopods. ‘The silica has been supposed to come 
 from the siliceous secretions of a minute sponge growing in 
 the cavities that afterwards became occupied by the glau- 
 conite. 
 
 Celadonite. A green earth with 53 per cent. of silica, from amygda- 
 loid, near Verona, Probably an impure chlorite. 
 
 Chloropal. A massive greenish-yellow to pistachio-green compact 
 mineral, somewhat opal-like in appearance, consisting chiefly of silica, 
 iron sesquioxide, and water. Montronite, Pinguite, Unghwarite and 
 Gramenite are varieties of it. 
 
 Stilpnomelane. Foliated and also fibrous, or as a velvety coating. 
 Black to brownish and yellowish bronze in color and lustre. G.= 
 3-3°4, Chiefly silica and iron oxides, with 8 to 9 per cent. of water. 
 Chalcodite of the Sterling Iron Mine, Antwerp, Jefferson County, 
 N. Y., is here included. 
 
 Serpentine. 
 
 Usually massive and compact in texture, of a dark oil- 
 green, oliye-green, or blackish-green color; also pale yel- 
 
808 DESCRIPTIONS OF MINERALS. 
 
 lowish-green, brownish-yellow and brownish-red, Occurs 
 also fibrous and lamellar. The lamellar varieties consist of 
 thin folia, sometimes separable, but brittle ; colors green- 
 ish-white, and light to dark green. Often in crystals pseu- 
 domorphous after chrysolite, chondrodite, and some other 
 minerals. 
 
 Lustre weak ; resinous, inclining to greasy. Finer varic- 
 ties translucent; also opaque. H.=25-4 G.=252°6 
 Feel sometimes a little unctuous. Tough. Jracture con- 
 choidal. 
 
 Composition. A hydrous silicate of magnesium, like tale; = 
 but containing much more water and much less silica. 
 H,Mg; Os Sin +1 aq = silica 43°48, magnesia 43°48, water 
 13:04—100. B.B. fuses with much difficulty on thin edges. 
 Yiclds water in the closed tube. Decomposed by hydro- 
 chloric acid, leaving a residue of silica. In some kinds the 
 Mg is replaced partly by Fe. 
 
 Specimens of a rich oil-green color, and translucent, 
 breaking with a splintery fracture, are sometimes called 
 precious serpentine, and the opaque kind, common serpen- 
 tine. 
 
 Fibrous serpentine with a silky lustre is called Chrysotile, 
 and also Amianthus. Unlike asbestus, which it resembles, 
 it affords much water in a closed tube. Metazite, Picro- 
 lite, and Baltumorite are coarse fibrous kinds. A foliated 
 variety, from Hoboken, N. J., was named Marmolite, be- 
 fore it was known to be serpentine. Antigorite is a foli- 
 ated variety. Williamsite is similar. Refdanskite contains 
 nickel. 
 
 A porcelain-like serpentine—the Meerschaum of Taberg 
 and Sala—has been called Porcellophite ; and a resin-like 
 variety, Retinalite and Vorhauserite. 
 
 Diff. The distinguishing characters are feeble lustre, 
 somewhat resinous, compact structure, little hardness, being 
 so soft as to be easily cut with a knife, and specific gravity 
 not over 2°6. 
 
 Obs. Serpentine occurs as a rock, and the several varie- 
 ties mentioned either constitute the rock or occur in it. 
 Occasionally it is disseminated through granular limestone, 
 giving the latter a clouded green color : this is the verd an- 
 tique marble, called also Ophiolyte. 
 
 Serpentine occurs in Cornwall; near Portsoy in Aber- . 
 deenshire, in Corsica, Siberia, Saxony, Norway at Snarum. 
 
HYDROUS SILICATES—MARGAROPHYLLITE SECTION. 309 
 
 In the United States it occurs at Phillipstown, Port Henry, 
 Gouverneur, Warwick, N. Y.; Newburyport, Westfield, 
 and Blandford, Mass.; at Kellyvale and New Fane, Vt.; 
 Deer Isle, Maine ; New Haven, Conn.; Bare Hills, Md. ; 
 Hoboken, N. J.; at Brewster’s, Putnam County, N. Y., 
 where it occurs pseudomorphous after chondrodite, chlo- 
 rite, enstatite, biotite, etc. ; in Canada at Orford, Ham, Bol- 
 ton, etc. 
 
 Serpentine forms a handsome marble when polished, es- 
 pecially when mixed with limestone, constituting verd- 
 antique marble. Its colors are often beautifully clouded, 
 and it is much’ sought for as a material for tables, jambs 
 for fire-places, and ornamental in-door work. Exposed to 
 the weather, it wears uneven, and soon loses its polish. 
 Chromic iron is usually disseminated through it, and in- 
 creases the variety of its colors. Near Milford and New 
 Haven, Conn., a handsome vyerd-antique marble occurs 
 which was formerly worked. A white lmestone, dotted 
 and spotted with green serpentine at Port Henry, Essex 
 County, N. Y., is much esteemed for its beauty, and is now 
 extensively worked. ‘The name serpentine alludes to the 
 varied green colors of such rocks. 
 
 Bowentte from Smithfield, R. I., has the composition of serpentine, 
 but the hardness 5°5-6, and the aspect of nephrite, with G.=2°59-2°8. 
 
 Bastite or Schiller Spar, is a foliated pyroxene or bronzite altered 
 nearly to serpentine. Antillite is similar. 
 
 Deweylite. 
 
 Massive. Whitish, yellowish, brownish-yellow, greenish, 
 
 reddish, in color, with the aspect of gum arabic or a resin. 
 Very brittle. H.=2-3'5. G.=1°9-2°25. 
 In composition near serpentine but containing 20 per 
 cent. of water. From Middlefield, Mass.; Bare Hills, 
 Maryland (Gymnite); Texas, Pa., and from the Fleims Val- 
 ley, ‘T'yrol. 
 
 Cerolite. Related to deweylite ; from Silesia. Limbachite from Lim- 
 bach, and Zvblitzite from Zoblitz, are similar, 
 
 Hydrophite. Like deweylite, but containing iron in place of part 
 of the magnesium. From Taberg in Smaoland. Jenkinsite is a 
 fibrous variety, occurring on magnetite, at O’Neil’s mine in Orange 
 County, N. Y. 
 
 Genthite or Nickel-gymnite. Similar to deweylite, but containing 
 much nickel and G@.=2°4, analysis affording Silica 35°36, nickel pro- 
 toxide 80°64, iron protoxide 0°24, magnesia 14°60, lime 0°26, water 
 
310 DESCRIPTIONS OF MINERALS. 
 
 19:09—100'19. From Texas, Pa.; Webster, N. C.; Michipicoton 
 
 Island, Lake Superior; Malaga, Spain ; Saasthal, Upper Valois. 
 Rottisite is similar. 
 
 Saponite. 
 
 Soft, clay-like, of the consistence before drying of cheese 
 or butter, but brittle when dry. Color white, yellowish, 
 grayish-green, bluish, reddish. Does not adhere to the 
 tongue. 
 
 Composition. A hydrous silicate of magnesia containing 
 some alumina. 
 
 From Lizard’s Point, Cornwall, in serpentine. Also from 
 geodes of datolite, Roaring Brook, Conn. ; in trap, north 
 shore of Lake Superior. 
 
 Kaolinite. 
 
 Trimetric. JA[=120°. Occurs massive, clay-like, but 
 consisting usually of thin, microscopic, rhombic or hex- 
 agonal, crystals ; either compact, friable, or mealy. 
 
 Color white, grayish-white, yellowish, sometimes brown- 
 ish, bluish, or reddish. Scales transparent or translucent ; 
 flexible, inelastic, greasy to the touch, H.=1-2°5. G.= 
 2'4-2'6. 
 
 Composition. TH, Al O; Si, +1 aq=Silica 46:4, alumina 39°7, 
 water 13°9=100. ‘The similarity of the composition to that 
 of serpentine will be seen on comparing the two formulas. 
 B.B. infusible. A blue color with cobalt solution. Yields 
 water in the closed tube. Insoluble in acids. 
 
 Obs. The soapy feel of kaolinite distinguishes a clay con- 
 sisting of it from other kinds of clay ; and when common 
 clays are “‘ unctuous ” it is usually owing to the presence of 
 kaolinite. Kaolinite has been made through the decompo- 
 sition of aluminous minerals, and especially the potash and 
 soda feldspars, orthoclase, albite, and oligoclase. In the 
 case of these feldspars the process (1) removes the alkalies ; 
 (2) leaves the alumina, or a large part of it, and part of the 
 silica ; and (3) adds water. So that, with orthoclase, K,Al 
 O,,8i, becomes changed to Hp“! O,S8ip+1aq; half the water 
 which is added replaces K, which is removed. Many gran- 
 ites, gneisses, and other feldspar-bearing rocks undergo 
 rapidly this change, so that extensive beds of kaolinite have 
 been formed and are now making in many regions. The 
 kaolinite is usually washed out by streams or the waves from > 
 the decomposed material to make the large pure deposits. 
 
WYDROUS SILICATES—MARGAROPHYLLITE SECTION. Sil 
 
 The New Jersey clay-beds of the Cretaceous formation are 
 mainly kaolinite, and have been thus formed. In other 
 cases permeating waters have washed out the oxides of iron 
 present, and have left the white clay in place. A pure 
 kaolinite bed occurs at Brandon, Vermont, along with a 
 limonite bed, where the rock decomposed was probably a 
 feldspathic hydromica slate. Most of the limonite beds of 
 Western New England afford kaolinite ; yet it is generally 
 more or less colored by iron oxide. 
 
 Common clays consist of finely-powdered feldspar, quartz, 
 and other mineral material, with often more or less kaoli- 
 nite. They burn red in case they contain iron in the state 
 ordinarily present in them of iron carbonate, or hydrous 
 iron oxide (limonite), or in combination with an organic 
 acid, or in some other alterable state of composition, heat 
 driving off the carbonic acid or water, or destroying the or- 
 ganic acid, and so leaving the red oxide of iron (or sesqui- 
 oxide), or favoring its:production. But the iron may be so 
 combined as not to give the red color; and this has been 
 found to be true with the clays from which the cream-col- 
 ored Milwaukee (Wisconsin) brick are made, and that of 
 other clay beds in that vicinity. The iron may be there in 
 the state of the silicate, zoisite, or epidote. 
 
 Pure kaolinite (or kaolin as it is ordinarily called) is 
 used in making the finest porcelain. For this purpose it is 
 mixed with pulverized feldspar and quartz, in the proportion 
 needed to give, on baking, that slight incipient degree of 
 fusion which renders porcelain translucent. ‘The name 
 kaolin is a corruption of the Chinese word Kauling, mean- 
 ing high ridge, the name of a hill near Jauchau-Fu, where 
 the mineral is obtained; and the petwntze (peh-tun-tsz) of the 
 Chinese, with which the kaolin is mixed in China for the 
 manufacture of porcelain, is, according to S. W. Williams, 
 a quartzose feldspathic rock, consisting largely of quartz. 
 The word porcelain was first given to China-ware by the 
 Portuguese, from its resemblance to certain sea-shells called 
 Porcellana; they supposed it to be made from shells, fish- 
 elue, and fish-scales (5. W. Williams). 
 
 The impure kaolin is used for stoneware and fire-bricks. 
 The presence of iron, in any state, makes a clay more or 
 less fusible, and therefore an unfit material for fire-bricks. 
 But a little of it exists in all clays employed for making or- 
 dinary bricks, and hence their red color, 
 
pi DESCRIPTIONS OF MINERALS. 
 
 Pholerite, Hailoysite, Smectite, Severite, Glagerite, Lenzinite, Bole, Th- 
 thomarge, are names of clay-like minerals. 
 
 Pinite. 
 
 Amorphous, and usually cryptocrystalline; but often 
 having the form of the crystals of other minerals from the 
 alteration of which it has been made. Colors grayish, green- 
 ish, brownish, and sometimes reddish. Lustre feeble; waxy. 
 Translucent to opaque. Acts like a gum on polarized light, 
 and thus indicates the absence of true crystallization, even 
 when under the forms of crystals. H.=2°5-3. G.=2°6-2°85. 
 
 Composition. Mostly (H,K) Al. Ow Sis. The pinite of Saxony 
 afforded Silica 46°83, alumina 27°65, iron sesquioxide 8°71, 
 magnesia 1:02, lime 0°49, soda 0°40, potash 6°52, water 3°85 
 =99-42; and, in another analysis, potash 10°74. The phy- 
 sical characters ally it to serpentine, and also nearly the 
 atomic ratio, and it may be viewed as a potash-alumina ser- 
 pentine. But at the same time it has very nearly the com- 
 position of a hydrous potash mica, or damourite (see next 
 page). 
 
 Obs. The varieties are pseudomorphs after different min- 
 erals, and hence comes a part of their variations in compo- 
 sition. They include Pinite, from the Pini Mine, near 
 Schneeberg and elsewhere ; Giesecrite, pseudomorph after 
 nephelite from Greenland, and from Diana, N. Y.; Dysyn- 
 tribite, from Diana, identical with gieseckite ; Pznitoid, 
 from Saxony ; Wilsonite, from Bathurst, Canada, having 
 the cleavage of scapolite ; ZTerenite, from Antwerp, N. Y., 
 like Wilsonite ; Agalmatolite, or Pagodite, from China, be- 
 ing one of the materials for carving into Images, ornaments, 
 models of pagodas, etc.; gigantolite and iberite, which have 
 the form of iolite. 
 
 Polyargite, Rosite, Cataspilite, Biharite are related materials. 
 
 Palagonite. Yellow to brownish yellow, garnet-red to black in 
 color, and resinous to vitreous in lustre. The material of some tufas, 
 and the result of change through the agency of steam or hot water at 
 
 the time, probably, of the deposition of the material. From tufas of 
 . Iceland, Germany, Italy, Sicily, and named from Palagonia, in Sicily. 
 
 HYDROMICA GROUP. 
 
 The following species are mica-like in cleavage and aspect, 
 but tale-like in wanting elasticity, greasy feel, and pearly 
 lustre. They are sometimes brittle. Common mica, mus- 
 
: HYDROMICA GROUP. 318 
 
 covite, readily becomes hydrated on exposure} but hydrous 
 micas are not all a result of alteration. The Hydromica 
 slates form extensive rock-formations, equal to those of the 
 ordinary mica schists. They were for the most part called 
 Lalcose slates (or Talk-schiefer in German) from their greasy 
 feel, until the fact was ascertained that they contained no 
 magnesia: a point demonstrated for the Taconic slates of 
 the western border of Massachusetts, by C. Dewey, in 1819, 
 and later, by G. I’. Barker, for those of Vermont. Pinite 
 is related in composition, but is not micaccous. 
 
 Margarodite. 
 
 Like muscovite (page 267), but inelastic. 
 
 Composition. Specimens from the topaz vein, Trumbull, 
 Conn., afforded Silica 46°50, alumina 33°91, iron sesquiox- 
 ide 2°69, magnesia 0°90, soda 2°70, potash 7:32, water 4°63, 
 fluorine 0°82, chlorine 0°31=99°78. Another from Litch- 
 field, Conn., accompanying cyanite, afforded water 5:26 per 
 cent., soda 4:10, potash 6:20, showing a large percentage of 
 soda. It is probable that both of these micas were originally 
 hydrous. 
 
 Damourite, 
 
 Mica-like, consisting of an aggregation of fine pearly scales, 
 yellow to white in color. 
 
 Composition. Near margarodite, being a hydrous potash 
 mica. A specimen from Brittany afforded Silica 45-22, 
 alumina 37°85, potash 11°20, water 5°25=99°52. The quan- 
 tivalent ratio for the protoxide, sesquioxide, silica, and 
 water is 1:9:12:2, instead of that of margarodite, which is 
 1:6:9:2. A schistose hydromica slate from Lehigh County, 
 Pennsylvania, afforded Dr. Genth, Silica 49°92, alumina 
 34:06, iron sesquioxide 0°91, magnesia 1°77, lime 0-11, soda 
 0-74, potash 6°94, water 6°52=100°9%7. 
 
 Obs. From a locality of cyanite in Brittany, and another 
 in Warmland ; also the constituents of a garnetiferous schist 
 at Salm-Chateau, in Belgium; and in part of extensive 
 schistose formations in Vermont, Western Massachusetts, 
 Western Connecticut, and also just west of New Haven, 
 Connecticut ; Eastern Pennsylvania, ctc. 
 
314 DESCRIPTIONS OF MINERALS. 
 
 For other analyses of hydromica slates, see Dr. Genth’s report on 
 the Mineralogy of Pennsylvania ; also Geological Report of F. Prime, 
 Jr., for 1874, p. 12. 
 
 Parophite. The material of a schist or slate—Parophite Schist— 
 which cuts like massive talc, is of greenish, yellowish, reddish, and 
 grayish colors, and is probably a damourite or hydromica slate, with 
 some free silica (quartz). An analysis afforded Silica 48°46, alumina 
 97°55, iron protoxide 5°08, magnesia 2°02, lime 2°00, soda 2°85, potash 
 5°16, water 7°14—99°81. It is from Pownal, Vt., and St. Nicholas, 
 Stanstead, and other neighboring parts of Canada. 
 
 Sericite. A damourite-like mineral, with the pearly lustre of talc, 
 and the composition of a hydrous mica ; it is the basis of a glossy 
 schist ; near Wiesbaden. ‘The scales are described by Rosenbusch as 
 appearing fibrous when highly magnified. Analysis afforded Silica 
 49°00, alumina, 23°65, iron protoxide 8:07, magnesia 0°94, lime 0°68, 
 soda 1°75, potash 9°11, water 3°47, titanic dioxide 1°39, silicon fluoride 
 1°60=100°14. 
 
 Paragonite. A hydrous mica containing soda in place of potash. 
 From Mount Campione, in the region of St. Gothard. Color whitish, 
 grayish, yellowish, greenish. Analysis afforded Silica 46°81, alu- 
 mina 40-06, magnesia 0°65, lime 1:26, soda 6°40, potash trace, water 
 4-82—100. Pregrattite. from the Tyrol, afforded soda 7:06, potash 
 1-71, water 5:04 ; it exfoliates like the Vermiculites. Cossaite is here 
 included. 
 
 Groppite. A rose-red to brownish-red foliated mineral from Gropp- 
 torp, Sweden. 
 
 Euphyllite. Mica-like, with folia rather brittle, pearly lustre, 
 white or colorless. Contains much sodium. An analysis afforded 
 Silica 41°6, alumina 42°3, lime 1°5, potash 3°2, soda 5-9, water 5°55=100. 
 Occurs with corundum at Unionville, Delaware County, Pa. 
 
 (illacherite. Mica-like ; strong pearly in lustre, grayish white to 
 white ; elastic. Analysis obtained 7°61 potash, 1°42 soda, 4°65 baryta, 
 and 4:43 water, besides silica, alumina, etc. 
 
 Cookeite. In minute mica-like scales, and in slender six-sided 
 prisms. Affords only 3-57 of potash, with 2°82 of lithia ; the water 
 13°41 per cent. Occurs on crystals of red tourmaline at Hebron and 
 Paris, Me., and has proceeded from its alteration. Named after Prof. 
 J. P. Cooke, of Cambridge, Mass. 
 
 Voigtite is the mica of a granite at Ehrenberg, near IImenau, which 
 has the composition of biotite, plus 9 to 10 per cent. of water. 
 
 Roscoelite. A vanadium-mica, of dark brownish-green color, occur- 
 ring in micaceous scales, and affording over 20 per cent. of vanadium 
 oxides, along with 47°69 of silica, 14°10 of alumina, 7°59 of potash, 
 4-96 of water, and a little magnesia and soda. From Granite Creek 
 Gold Mine, El Dorado County, California. 
 
 F'ahlunite. 
 
 In six and twelve-sided prisms, usually foliated, parallel 
 to the base, but owing its prismatic forms to the mineral 
 from which it was derived, Tolia soft and brittle, of a 
 
WYDROUS SILICATES. B10 
 
 grayish-green to dark olive-green color, and pearly lustre. 
 Ope a 
 
 Composition. A hydrous silicate of aluminum and iron 
 with little or no alkali, and in this last point differing from 
 pinite. An average specimen afforded Silica 44:60, alumina 
 30°10, iron protoxide 3°86, manganese protoxide 2:24, mag- 
 nesia 6°75, lime 1°35, potash 1:98, water 9°35. — 100°23. 
 B.B. fuses to a white glass. In a closed tube gives water. 
 Insoluble in acids. 
 
 Diff, It is distinguished from tale by affording much 
 water before the blowpipe, and readily by its association 
 with iolite, and its large hexagonal forms, with brittle folia. 
 
 Obs. Fahlunite has been derived from the alteration of 
 iolite. ‘The quantivalent ratio of iolite for the protoxides, 
 sesquioxides, and silicon is 1:3:5; and for fahlunite, the 
 same, with 1 for the water, making the whole 1:3:5:1. The 
 hydration appears to go on at the ordinary temperature, 
 and in some localities all the iolite to a considerable depth 
 in the rock is changed to fahlunite. There are different 
 varieties, depending on the amount of water, and the con- 
 ditions under which the change has taken place. The 
 names they have received are Hydrous Iolite, Chlorophyllite, 
 Esmarkite, Aspasiolite, Pyrargillite, Triclasite. Fahlunite 
 was so named from its locality, Fahlun, Sweden ; and Ohlo- 
 rophyllite from its greenish color and foliated structure ; the 
 specimens to which it was given occurring at Unity, N. H. 
 Haddam, Ct., is another locality. Gigantolite, Iberite, are 
 also altered iolite, but they contain potash, and belong 
 hence to the Pinite Group. 
 
 Hisingerite. 
 
 Massive; reniform ; of a black to brownish-black color, 
 yellowish-brown streak, greasy lustre inclining to vitreous. 
 Mio. G2 3°045, 
 
 Composition. A hydrous iron silicate. Silica 35:9, iron 
 sesquioxide 42°6, water 21°5=100. But in some analyscs 
 part of the iron is in the protoxide state. B.B. fuses with 
 difficulty to a magnetic slag. 
 
 Obs. From Sweden, Norway, Finland. Scotiolite and 
 Degeroite are referred to it. Melanolite, from Milk-Row 
 quarry, near Charlestown, Mass., is related in composition, 
 if the material analyzed was a pure species. 
 
316 DESCRIPTIONS OF MINERALS. 
 
 Approaches in composition the chlorites, and may belong 
 to that group. 
 
 Gillingite from Sweden, including Thraulite from Bavaria, Epichlo- 
 rite, and Lillite, are other hydrous silicates containing iron. 
 
 Ekmannite, foliated, chlorite-like, occurs in the rifts of magnetite, 
 in Sweden; it is a hydrous iron silicate, but the iron is mostly in the 
 protoxide state. 
 
 Neotocite (Stratopeite) and Wittingite are results of the alteration of 
 rhodonite, and contain manganese. Stiubelite also contains manganese 
 oxide. 
 
 Strigovite from Striegau, Siberia, and Jollyte from Bodenmais in 
 Bavaria, are hydrous silicates of aluminum and iron, with little mag- 
 nesium. 
 
 CHLORITE GROUP. 
 
 The chlorite group includes the hydrous Swbszlicates of 
 the Margarophyllite Section and also some related species 
 that are Unisilicates. The proportion of silica is small, the 
 percentage afforded by analyses being under 38, and mostly 
 nnder 30. ‘The minerals when well crystallized are foliated 
 like the micas, and have the plane angle of the base of the 
 crystals 120°, but the folia are inelastic and in some species 
 brittle. They also occur in fibrous and in fine granular and 
 compact forms, and the latter are usually most common. 
 Green, varying from light to blackish green, is the prevail- 
 ing color, yet gray, yellowish, reddish, and even white and 
 black also occur; and the colored transparent or translu- 
 cent are dichroic. The green color is owing to the presence 
 of iron, and fails only in species containing little or none 
 of it. All of the species yield water in a closed tube. 
 The quantivalent (or combining-power) ratio for R+8 and 
 Si is, in the 
 
 Pyrosclerite subdivision.....-.--. 12: 
 Chlorite subdivision......-..++++: tS 1s 2 ie 
 Chloritoid subdivision. .......-+-- 1:it01:4. 
 
 The chlorite subdivision includes Penninite, Ripidolite 
 and Prochlorite, together with some related dark-green to 
 blackish-green species. Some species of this subdivision 
 characterize extensive rock formations, making chlorite 
 
CHLORITE GROUP. ole 
 
 schist or slate ; and they give rise also to chloritic varieties 
 of other rocks. Moreover, chlorite is a result of the altera- 
 tion of pyroxene, hornblende, and some other iron-bearing 
 minerals; and pyroxenic igneous rocks, like doleryte, are 
 often strongly chloritic (as revealed by the microscopic 
 examination of thin transparent slices), in consequence of 
 this alteration—but alteration that took place before the 
 rock had cooled. Such green chloritic material, where the 
 species is not determinable, has been called Viridite. The 
 cavities in amygdaloid are often lined, and sometimes filled, 
 by a species of chlorite, which was made from certain con- 
 stituents of the amygdaloid in the manner just stated ; and 
 the rocks adjoining trap dikes are at times penetrated by 
 chlorite made in them by means of the heat, and the mois- 
 ture contained in them or ascending with the erupted rock. 
 
 Pyrosclerite. 
 
 Trimetric or monoclinic. Mica-lke in cleavage; folia 
 flexible, not elastic, and pearly in lustre. Color apple-green 
 to emerald-green. H.=3. G.=2°74, 
 
 Composition. (Mg, 4Al), O.58i1,+3 aq=Silica 38°9, alu- 
 mina 14°8, magnesia 34°6, water 11°7=100. B.B. fuses to a 
 grayish glass ; gelatinizes with hydrochloric acid. 
 
 Obs. Occurs in serpentine, on Elba. 
 
 Chonicrite (Metaxoite) is related to the above in composition, but 
 affords 12 to 18 per cent. of lime. 
 
 Vermiculite. 
 
 Mica-like in cleavage. Grayish, brownish, and yellowish- 
 brown in color. In aggregated scales. Also in large mi- 
 eaceous crystals or plates. amine flexible, not elastic. 
 Lustre pearly. 
 
 Composition. Me, (He,Al) O,.8i;. When heated it exfo- 
 liates, and when scaly-granular the scales open out into 
 worm-like forms ; and thence the name, from the Latin 
 vermiculor, I breed worms ; B.B. fuses finally to a gray 
 mass. From Milbury, Mass. 
 
 Jefferisite is a similar mineral in composition and exfoliation, occur- 
 ring in broad folia. Composition $Mg, 4(Fe,,Al,)O,.8i,. From veins 
 in serpentine in Westchester, Pa. Culsageeite from Culsagee, North 
 
313 DESCRIPTIONS OF MINERALS. 
 
 Carolina; Hallite from Lerni, Delaware Co., Pa.; Protovermiculite 
 from Magnet Cove, Ark., are other micaceous hydrous unisilicates 
 similar to vermiculite and jefferisite in exfoliation. Kerrite and 
 Maconite are related to the above. They are from Franklin, Macon 
 Co., North Carolina. Pelhamite is from Pelham, Mass. 
 
 Penninite.—Chlorite in part. Pennine. - 
 
 Rhombohedral. Cleavage basal and highly perfect, mica- 
 like. Also massive, consisting of an aggregation of scales, 
 and cryptocrystalline. 
 
 Color green of various shades ; also yellowish to silver- 
 white, and rose-red to violet. Lustre pearly ou cleavage 
 surface. Transparent to translucent. Lamine flexible, 
 not elastic. H.=2-2°5, 3 on edges. G.=2°6-2°85. 
 
 Composition. A specimen from Zermatt, in the Pennine 
 Alps, afforded Silica 33°64, alumina 10°64, iron sesquioxide 
 83, magnesia 34:95, water 12-40=100°46. ‘The rose-red, 
 from Texas, Pa., gave Silica 33°20, alumina 11°11, chro- 
 mium oxide 6°85, iron sesquioxide 1°43, magnesia 35°54, 
 water 12°95, lithia and soda 0°28, potash 0:10 =101°46. 
 Other Texas specimens afforded 0°90 to 4°78 per cent. of 
 chromium oxide. B.B. exfoliates somewhat and fuses with 
 difficulty. Partially decomposed by hydrochloric acid, and 
 wholly so by sulphuric acid. 
 
 From Zermatt, Ala in Piedmont, the Tyrol, etc. Adm- 
 mererite, Rhodochrome, and Rhodophyllite include the red- 
 dish variety from near Miask, Russia; Texas, Pennsylva- 
 nia; etc. Pseudomorphs after hornblende, named Loganite, 
 have the composition of this species ; and so has the mas- 
 sive mineral called Psewdophite and Allophite. 
 
 Delessite. A fibrous mineral near the above in composition, -rom 
 amygdaloid at Oberstein. 
 
 Euralite is an amorphous chlorite near. Penninite, from Eura, Fin- 
 Jand ; from amygdaloid. : 
 
 Diabantite (Diabantochronyn) is a chlorite from amygdaloid. A 
 Farmington (Conn.) specimen afforded Hawes, Silica 83°68, alumina 
 10°84, iron sesquioxide 2°86, iron protoxide 24°33, MnO and CaO 1°11, 
 magnesia 16°52, soda 0°33, water 10°02=—99°69. 
 
 Chloropheite is a doubtful species of chlorite, from amygdaloid. 
 
 Ripidolite.—Chlorite, in part. 
 
 Monoclinic. Similar in cleavage and mica-like character 
 to penninite, and also in its colors, lustre, hardness and 
 specific gravity. 
 
CHLORITE GROUP. 319 
 
 Composition. A specimen from Chester Co., Pennsylvania, 
 afforded Silica 31:34, alumina 17°47, chromium sesquioxide 
 1°69, iron sesquioxide 3°85, magnesia 33°44, water 12°60= 
 100°39. B.B. and with acids nearly like penninite. A va- 
 riety from Willimantic, Ct., exfoliates like vermiculite and 
 jefferisite. 
 
 Kotschubeite is a red variety from the Urals. 
 
 Clinochlore and Grastite are here included. Occurs at 
 Achmatovsk and elsewhere in the Urals; at Ala, Piedmont ; 
 at Zermatt ; at Westchester, Unionville and Texas, Pa.; at 
 Brewster’s, N. Y. 
 
 Prochlorite.—Chlorite in part. 
 
 Hexagonal. Similar in cleavage and mica-like characters 
 to the preceding. Color green to blackish-green ; some- 
 times red across the axis by transmitted light. Laminez 
 not elastic. 
 
 Composition. A specimen from St. Gothard afforded Sih- 
 ca 25:36, alumina 18°56, iron protoxide 28°79, magnesia 
 17:09, water 8:°96=98'70 ; and a North Carolina specimen, 
 Silica 24°90, alumina 21°77, iron sesquioxide 4°60, iron 
 protoxide 24:21, manganese protoxide 1°15, magnesia 12°78, 
 water 10°59=100. B.B. same as for preceding. 
 
 Lophoite, Ogcoite, Helminthe belong here. Occur at St. 
 Gothard, at Greiner in the Tyrol, at Traversella in Pied- 
 mont, and many other places in Europe. Also at Steele’s 
 Mine, N. C. 
 
 _ Leuchienbergite is a prochlorite with the base almost solely magne- 
 sium. 
 
 Aphrosiderite, Metachiorite are near the above in composition. 
 
 Venerite is a pale-green earthy chlorite, from a magnetite mine in 
 Berks County, Pa. 
 
 Corundophilite is a chlorite near prochlorite in composition. Occurs 
 with corundum at Asheville, N. C. 
 
 Grochauite is from Grochau in Silesia. 
 
 Cronstedtite. Hexagonal, with perfect basal cleavage. Black, G.= 
 3:35. Consists mainly of silica, iron oxides, and water, with a little 
 manganese oxide. From Bohemia and Cornwall. 
 
 Thuringite. Another hydrous iron silicate, having G.=3'15-3:20, 
 from Thuringia, and also Hot Springs, Arkansas, and near Harper’s 
 Ferry, on the Potomac. Pattersonite, from Unionville, Pa., is near it. 
 
 Margarite.—Emerylite. Diphanite. Clingmanite. Corundellite. 
 
 Trimetric. Foliated, mica-like. Lamine rather brittle. 
 Color white, grayish, reddish. Lustre of cleavage surface 
 
320 DESCRIPTIONS OF MINERALS, 
 
 strong pearly and brilliant, of sides of crystals vitreous. 
 Hie hats. a8. 
 
 Composition. H,RAl, O19 Si,—Silica 301, alumina 51.2, 
 lime 11°6, soda 2°6, water 45—=100. B.B. whitens and fuses 
 on the edges. 
 
 Obs. Often associated with corundum and diaspore. Oc- 
 curs in Asia Minor; at Sterzing in the Tyrol; in the 
 Urals ; in Village Green, and Unionville, Pa. ; in Buncombe 
 County, N. C.; at Chester, Mass. Named from the Greek 
 margarites, a pearl. 
 
 Willcowite is near margarite. Dudileyite is an alteration product of 
 margarite. 
 
 Chloritoid.—Masonite. Phyllite, Ottrelite. 
 
 Monoclinic or triclinic. Cleavage basal, perfect. Also 
 coarse foliated massive; and in thin disseminated scales 
 (phyllite or ottrelite). Brittle. 
 
 Golor dark gray, greenish, to black. Lustre of cleavage 
 surface somewhat pearly. 
 
 Composition. FeAl O,Si+1 aq=Silica 24:0, alumina 40°5, 
 iron protoxide 28-4, water 7-1=100. B.B. becomes darker 
 and magnetic, but fuses with difficulty. Decomposed com- 
 pletely by sulphuric acid. 
 
 Obs. Found at Kossoibrod, Urals, with cyanite ; in Asia 
 Minor, with emery; at St. Marcel ; Ottrez, France (Ottre- 
 lite); Chester, Mass.; in Rhode Island (Masonite); at 
 Brome and Leeds, Canada. Phyllite in scales character- 
 izes the “spangled mica slate” of Newport, R. IL, and 
 Sterling, Goshen, etc., Mass. 
 
 Seybertite. Occurs in somewhat mica-like, or thin foliated forms, 
 with perfect basal cleavage, and lamin brittle, the color reddish or 
 yellowish brown to copper-red. Analysis by Brush obtained Silica 20°24, 
 alumina 39°13, iron sesquioxide 3°27, magnesia 20°84, lime 13°69, water 
 1:04, potash and soda 1°48, zirconia 0-75—100°39, giving the quantiva- 
 lent ratio for protoxides, sesquioxides, silica, and water 6 :9:5:%. From 
 Amity, N. Y.; Slatoust, Urals (Xanthophyllite) ; Fassa Valley (Bran- 
 disite and Disterrite). 
 
 IV. HYDROCARBON COMPOUNDS, 
 
 The following are the subdivisions here used, 
 I. Srrptr Hyprocarzons : Marsh-gas, Mineral oils, and 
 Mineral wax. 
 
 N 
 
SIMPLE HYDROCARBONS. 321 
 
 Il. OXYGENATED HyprocarBons: mostly resins. 
 III. ASPHALTUM AND MINERAL COALS. 
 
 I, SIMPLE HYDROCARBONS. 
 Marsh-Gas.—Light Carburetted Hydrogen. 
 
 Colorless and inodorous gas in the pure state. Inflam- 
 mable, and burns with a yellow flame. Composition CH,= 
 Carbon 75, hydrogen 25=100. 
 
 Obs. This gas (mixed with more or less carbon dioxide 
 and nitrogen) often rises in bubbles through the waters of | 
 marshes, whence its name ; and frequently it is discharged 
 from fissures into coal mines in large quantities, constituting 
 the fire-damp of the mine. Such natural discharges, called 
 blowers, sometimes continue for months. It is the cause of 
 the explosions in mines, a mixture of it with the atmo- 
 sphere exploding on the approach of the flame of a can- 
 dle. It destroys life both by the concussion occasioned, by 
 the exhaustion of the atmosphere of oxygen, and by the 
 production of carbon dioxide which takes place. The gas 
 which issues from the oil springs or wells of Western New 
 York (Fredonia), and Hastern Pennsylvania, is marsh-gas 
 mixed with other vapors of the Marsh-gas series. It is used 
 in some places for lighting houses, and even villages ; and 
 also for other purposes where heat is required. 
 
 The gas bubbling up from a marsh in Europe afforded 
 Websky Carbon dioxide 2-97, marsh-gas 43:36, nitrogen 
 53°67=100. ‘The first of these ingredients is in fact one 
 of the more abundant results of decomposition, whether 
 vegetable or animal; and the percentage is here small 
 because the gas is soluble in water, and because it readily 
 enters into combinations with the earthy ingredients of 
 plants. 
 
 Petroleum. 
 
 Mineral oils, varying in density from 0:60 to 0°85. Solu- 
 ble in benzine or camphene. ‘They consist chiefly of liquids 
 of the Naphtha and Ethylene series. The composition of 
 the Naphtha or Marsh-gas series is expressed by the general 
 formula, O,H.,+2, of which Marsh-gas is the first or 
 lowest term; and that of the Ethylene series by the for- 
 mula, C,H,,=Carbon 85-71, hydrogen 14:29=100. The 
 oils vary greatly in density from the lightest pe too 
 
 2 
 
B22 DESCRIPTIONS OF MINERALS. 
 
 inflammable for uso in lighting, to thick viscid fluids ; and 
 thence they pass by insensible gradations into asphaltum or 
 solid bitumen. ‘he Marsh-gas series contains also gases, 
 of the composition C, H, and OC, H, and these, in addition to 
 Marsh-gas, often exist in connection with petroleum. 
 
 Petroleum occurs in rocks of all ages, from the Lower 
 Silurian to the most recent ; in limestones, the more com- 
 pact sandstones, and shales ; but it is mostly obtained from 
 large cavities or caverns existing among the earth’s strata. 
 Black shales and much bituminous coal afford it abundantly 
 when they are heated. But the oil obtained is not present 
 in these rocks, for when the rocks are treated with benzine, 
 the benzine takes up little or none ; instead, the rocks con- 
 tain an insoluble hydrocarbon, which yields the oil when 
 heat is applied. 
 
 In the United States the oil, or the hydrocarbon which 
 yields it, has been observed in beds of the Lower and Upper 
 Silurian, Devonian, Carboniferous, Triassic, Cretaceous, and 
 Tertiary eras. Surface oil springs also occur in many places, 
 as at Cuba, Alleghany County, N. Y., called Seneca Oil 
 Spring ; and on a large scale in Santa Barbara, Southern 
 California; at Rangoon in Burmah, where there are about 
 100 wells ; on the peninsula of Apcheron, on the Caspian, 
 and elsewhere. Pliny mentions the oil spring of Agrigen- 
 tum, Sicily, and says that the liquid was collected and used 
 for burning in lamps, as a substitute for oil. Moreover he 
 distinguishes the oil from the lighter and more combustible 
 naphtha, a locality of which about the sources of the Indus, 
 <‘in Parthia,” he mentions. 
 
 Petroleum is obtained chiefly at the present time from 
 more or less deeply-seated subterranean chambers or cavities 
 among the rock strata, reached by ‘boring. Being under 
 pressure of gas associated with it, and also, in many Cases, 
 that also of water, it rises to the surface in the boring, and 
 sometimes makes a ‘‘spouting” well. As early as 1833, 
 Hildreth mentioned the discharge of oil with the waters 
 of the salt wells of the Little Kanawha valley; and speaks 
 also of a well near Marietta, Ohio, which threw out at one 
 time, he says, 50 to 60 gallons of oil at “ each eruption.” 
 
 The mineral oil of the rocks has been formed through 
 the decomposition of animal and vegetable substances. 
 From the nature of the rocks which most abound in the 
 species of hydrocarbons that yield oil, it is evident that 
 
SIMPLE HYDROCARBONS. S39 
 
 the rock material was in the state of a fine mud » that 
 through this mud much vegetable or animal matter was 
 distributed, almost in the condition of an emulsion ; that 
 the stratum of this mud becoming afterward overlaid by 
 other strata, the decomposition of vegetable or animal mat- 
 ter went forward without the presence of atmospheric air, 
 or with only very little of it. Under such circumstances 
 either vegetable material or animal oils might be converted, 
 as chemists have shown, into mineral oil. Dry wood con- 
 sists approximately (excluding the ash and nitrogen) of 6 
 atoms of carbon to 9 of hydrogen, and 4 of oxygen. If now 
 all the oxygen of the wood combines with a part of the car- 
 bon to form carbonic acid, and this 2. C 0,, thus made, is re- 
 moved, there will be left C,H,; twice this, C, .,, 18 the 
 formula of a compound of the Marsh-gas or Naphtha series. 
 Again animal oils, by decomposition under similar cir- 
 cumstances, produce like results. Removing from oleic 
 acid its oxygen, O,, and 1 of carbon—together equivalent to 
 1 of carbonic acid—there is left C,, Hy, which is an oil of 
 the Ethylene series ; and margaric acid would leave, in the 
 same way, C,, H;,, or a combination of oils of the Marsh-gas 
 or Naphtha series. Warren and Storer have obtained from 
 the destructive distillation of a fish-oil, after its saponifica- 
 tion by lime, several compounds of the Marsh-gas series, be- 
 sides others of the Ethylene and Benzole series. The de- 
 compositions in nature may not have been as simple as those 
 in the above illustrations, yet the facts warrant the infer- 
 ence that the oils may have been derived either from vege- 
 table or animal matters. Fossil fishes are often found abun- 
 dantly in black oil-yielding shales, and Dr. Newberry has 
 suggested that fish-oil may be the most abundant source of 
 the oil and the oil-yielding hydrocarbons. 
 
 The oil which is collected in great cavities among the 
 earth’s strata, as in Western Pennsylvania, is believed by 
 most writers on the subject to have come from underlying 
 rocks, such as the black oil-yielding shales. The heat pro- 
 duced in the rocks by the friction attending movements and 
 uplifts, is supposed to have been sufficient to have made the 
 oil from the hydrocarbon of the carbonaceous shale or other 
 rock, and to have caused it to ascend among the strata to 
 the cavities where it was condensed, and now is found by 
 boring. 
 
 The oils, exposed to the air and wind, undergo change in 
 
324 DESCRIPTIONS OF MINERALS. 
 
 three ways. First: the lighter naphthas evaporate, leaving 
 the denser oils behind ; and, ultimately, the viscid bitumens, 
 or else paraffin, according as paraffin is present or not in 
 the nativeoil. At the naphtha island of I'schelekan in Per- 
 sia, there are large quantities of Neft-gul, as it is called, 
 which is nearly pure paraffin. The hot climate of the Cas- 
 pian is favorable for such a result. Secondly: ther emay 
 be a loss of hydrogen from its combination with the oxygen 
 of the atmosphere to form water, which escapes. ‘Thus the 
 oils of the Naphtha series may change into those of the Ethy- 
 lene or Benzole series. Thirdly: there may be an oxidation 
 of the hydrocarbon of the oils, producing asphaltum or 
 more coal-like substances, like albertite. 
 
 The word naphtha is from the Persian, nafata, to exude ; 
 and petroleum from the Greek, petros, rock, and the Latin, 
 oleuwm, oil. 
 
 Hachettite—Mountain Tallow. Hatchetine. 
 
 Like soft wax in appearance and hardness, of a yellowish- 
 white to greenish-yellow color. 
 
 Composition. Related to paraffin. 
 
 From the coal-measures of Glamorganshire in Wales. 
 
 rocerite is like wax or spermaceti in consistence. Soluble in ether. 
 The original was from Moldavia. Along with another wax-like sub- 
 stance, called Urpethite, it constitutes the “‘ mineral wax of Urpeth 
 Colliery.” Zietrisikite is like beeswax, and is insoluble in ether ; 
 from Moldavia. 
 
 Elaterite.—Mineral Caoutchouc. Elastic Bitumen. 
 
 In soft flexible masses, somewhat resembling caoutchouc 
 or India rubber. Color brownish-black ; sometimes orange- 
 red by transmitted light. G,=0°9-1'25. Composition: Car- 
 bon $5°5, hydrogen 13°3=98°8. It burns readily with a yel- 
 low flame and bituminous odor. 
 
 Obs. From a lead mine in Derbyshire, England, and a 
 coal mine at Montrelais. It has been found at Woodbury, 
 Ct., in a bituminous limestone. 
 
 Fichtelite and Hartite are crystallized hydrocarbons, of the Cam- . 
 phene series. Branchite, Dinite, and Ixolyte are related to Hartite. 
 Konlite, Naphthalin, and ldrialite are native species of the Benzole 
 series, Aragotite, from California, is near Idrialite. 
 
OXYGENATED HYDROCARBONS. 825 
 
 Il. OXYGENATED HYDROCARBONS. 
 
 Amber. 
 
 In irregular masses. Color yellow, sometimes brownish 
 or whitish; lustre resinous. ‘l'ransparent to translucent. 
 H.=2-2°5. G.=1:18. Electric by friction. 
 
 Amber is not a simple resin, but consists mainly (85 to 90 
 per cent.) of a resin which resists all solvents, called Suc- 
 cinite, and two other resins soluble in alcohol and ether, 
 besides an oil, and 24 ,to 6 per cent. of Succinic acid. 
 
 Obs. Occurs in the loose deposits along coasts, especially 
 Tertiary strata, in masses from a very small size to that of 
 aman’s head. In the Royal Museum at Berlin, there is a 
 mass weighing 18 pounds. On the Baltic coast it is most 
 abundant, especially between Kénigsberg and Memel. It 
 is met with at one place in a bed of bituminous coal; it 
 also occurs on the Adriatic ; in Poland ; on the Sicilian 
 coast near Catania ; in France near Paris, in clay ; in China. 
 It has been found in the United States, at Gay Head, 
 Martha’s Vineyard ; Camden, N. J.; and at Cape Sable, 
 near the Magothy River, in Maryland. 
 
 It is supposed, with good reason, to be a vegetable resin 
 which has undergone some change while inhumed, a part 
 of which is due to acids of sulphur proceeding from decom- 
 posing pyrites or some other source. It often contains in- 
 sects, and specimens of this kind are so highly prized as 
 frequently to be imitated for the shops. Some of the insects 
 appear evidently to have struggled after being entangled in 
 the then viscous resin, and occasionally a leg or a wing is 
 found some distance from the body, having been detached 
 in the struggle for escape. 
 
 Amber is the elektron of the Greeks ; from its becoming 
 electric so readily when rubbed, it gave the name electricity 
 to science. It was also called swecinum, from the Greek 
 succum, juice, because of its supposed vegetable origin. 
 
 It admits of a good polish and is used for ornamental 
 purposes, though not very much esteemed, as it is wanting 
 in hardness and brilliancy of lustre, and moreover is easily 
 imitated. It is much valued in Turkey for mouth-pieces 
 to pipes. 
 
 Oopalite, or Mineral Copal, Waichowitte, Ambdrite (the New Zealand 
 resin), Huosmite, Scleretinite, Middletote are some of the names of 
 
 other fossil resins ; Geocerite, and Geomyricite, of wax-like oxygenated 
 species ; Guyaquillite, Bathvillite, Torbanite, Jonite (from Ione valley, 
 
326 DESCRIPTIONS OF MINERALS. 
 
 California), of species not resinous in lustre ; Tasmanite and Dysodile, 
 of kinds containing several per cent. of sulphur. Wollongongite, from 
 Australia, is black, and looks like cannel coal. 
 
 Ill. ASPHALTUM AND MINERAL COALS. 
 Asphaltum. 
 
 Amorphous and pitch-like. Burning with a bright flame 
 and melting at 90° to 100° F. Soluble mostly or wholly in 
 camphene. It is a mixture of hydrocarbons, part of which 
 are oxygenated. 
 
 Obs. Asphaltum is met with abundantly on the shores of 
 the Dead Sea, and in the neighborhood of the Caspian. <A 
 remarkable loeality occurs on the island of Trinidad, where 
 there is a Jake of it about a mile and half in circumference. 
 The bitumen is solid and cold near the shores; but gradu- 
 ally increases in temperature and softness toward the cen- 
 tre, where it is boiling. The appearance of the solidified 
 bitumen is as if the whole surface had boiled up in large 
 bubbles and then suddenly cooled. The ascent to the lake 
 from the sea, a distance of three quarters of a mile, is coy- 
 cred with the hardened pitch, on which trees and vegetation . 
 flourish, and here and there, about Point La Braye, the 
 masses of pitch look like black rocks among the foliage. It 
 occurs also in South America about similar lakes in Peru, 
 where it is used for pitching boats ; and in California on 
 the coast of Santa Barbara. Large deposits occur in sand- 
 stone in Albania. It is also found in Derbyshire, and with 
 quartz and fluor in granite in Cornwall, and at many other 
 places. } 
 
 Albertite.. 
 
 Coal-like in hardness, but little soluble in camphene, and. 
 only imperfectly fusing when heated ; but having the lustre 
 of asphaltum, and softens a little in boiling water. H.=1-2. 
 GT. 
 
 Fills fissures in the Subcarboniferous rocks near Hills- 
 borough, Nova Scotia, and supposed to have been derived 
 from the hydrocarbon of the adjoining rock, and to have 
 been oxidized at the time it was formed and filled the 
 fissure. 
 
 Grahamite is a related material from West Virginia, 20 miles south 
 of Parkersburg. H.=2. G.=1:145. Soluble mostly in camphene, 
 but melts only imperfectly. An analysis afforded carbon .76°45, hy- 
 drogen 7°82, oxygen (with traces of nitrogen) 13°46, ash 2:°26=100. 
 
MINERAL COAL. Bye: 
 
 MINERAL COAL. 
 
 Massive. Color black or brown; opaque. Brittle or im- 
 perfectly sectile. H.=0-5-2°5. G.=1'2-1°80. 
 
 Composition. Carbon, with some oxygen and hydrogen, 
 more or less moisture, and traces also of nitrogen, besides 
 some earthy mineral which constitutes the ash. ‘I'he car- 
 bon, or-part of it, is in chemical combination with the 
 hydrogen and oxygen. 
 
 Coals differ in the amount of volatile ingredients given , 
 off when heated. ‘These ingredients are moisture, and hy- 
 drocarbon oils and gas, derived from the same class of 
 insoluble hydrocarbons that is the source of the oil of shales 
 and other rocks. 
 
 VARIETIES. 
 
 1. Anthracite. Anthracite (called also glance coal and 
 stone coal) has a high lustre, and is often iridescent. It is 
 quite compact and hard, and has a specific gravity from 1°3 
 to 1°75. It usually contains 80 to 93 per cent. of carbon, 
 with 4 to 7 of volatile matter ; the rest consisting of earthy 
 impurities. Burns with a feeble blue flame. 
 
 Those yielding the most volatile ingredients are called 
 Sree-burning anthracite. 
 
 2. Bitwninous Coal. Bituminous coal varies much in the 
 amount of oil, coal-tar, or gas it yields when heated; and 
 there is a gradual passage in its varieties through sem- 
 anthracite to anthracite. It is of a black color, with the 
 powder black, but it is softer than anthracite, and less 
 lustrous. The specific gravity does not exceed 1°5. The 
 volatile ingredients constitute usually between 20 and 40 
 per cent. 
 
 Caking Coal includes that part of bituminous coal which 
 softens when heated and becomes viscid, so that adjoining 
 pieces unite into a solid mass. It burns readily with a 
 lively yellow flame, but requires frequent stirring to prevent 
 its agglutinating, and so clogging the fire. Non-caking coal 
 resembles the caking in appearance, but does not soften and 
 cake. The chemical difference between caking and non- 
 caking coal is not understood. 
 
 3. Cannel Coal is very compact and even in texture, with 
 little lustre, and breaks with a large conchoidal fracture. It 
 takes fire readily, and burns without melting to a clear yel- 
 
_ 
 
 328 DESCRIPTIONS OF MINERALS. 
 
 low flame, and has hence been used as candles—whence the 
 name. It affords when. heated a large amount of mineral 
 oil, and may be used for its production. ‘The volatile in- 
 gredients sometimes amount to 50 or 60 per cent. It is 
 often made into inkstands, snuff-boxes, and other similar 
 articles. 
 
 4. Brown Coal usually has a brownish-black color, and 
 contains 15 to 20 per cent. of oxygen, but much resembles 
 in appearance bituminous coal. The term brown coal is ap- 
 plied generally to any coal more recent in origin than the 
 era of the great coal beds of the world. The name lignite 
 has sometimes the same general application, though without 
 strict propriety. Lignite is the part of brown coal which 
 has the woody structure still apparent. 
 
 Tet resembles cannel coal, but is harder, of a deeper black 
 color, and has a much higher lustre. It receives a brilliant 
 polish, and is set in jewelry. Itis the Gagates of Diosco- 
 rides and Pliny, a name derived from the river Gagas, In 
 Syria, near the mouth of which it was found, and the origin 
 of the term jet now in use. 
 
 Native Coke resembles somewhat artificial coke, but is 
 more compact, and some varieties of it afford a consider- 
 able amount of bitumen. It occurs at the Edgehill mines 
 near Richmond, Virginia, according to Genth, who attri- 
 butes its origin to the action of a trap eruption on bitumi- 
 nous coal. 
 
 It is now well established that mineral coal is mainly of 
 vegetable origin, and that the accumulations out of which 
 the coal beds were made were very similar in character, 
 though not in kinds of plants, to the peat beds of the pres- 
 ent day. Peat is vegetation which has undergone, in part, 
 the change to coal; and in some cases it has become brown 
 coal. The conditions of change are somewhat different from 
 those of the beds of good coal, since, in the case of the peat, 
 the air has access, while in that of the coal the air was more 
 or less excluded by overlying strata; and the more perfect 
 the exclusion, other things equal, the better the coal. As 
 the composition of mineral coal 1s closely related to that of 
 mineral oils, the explanation of the origin of the latter, given 
 on page 323, suffices to illustrate also the origin of the 
 former. With a less complete exclusion of the air, oxygen- 
 ated hydrocarbon compounds, like coal, would be a natural 
 result. 
 
MINERAL COAL. 329 
 
 The following are afew analyses of coals, the moisture 
 excluded: 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Carbon.| Hydr.| Oxyg. | Nitr. Sulph. | Ash. 
 1 | Anthracite, Pennsylvania. .| 90°45 | 2°43] 2°45 |...../..... 4°67 
 2 | Anthracite, Pennsylvania. .| 92°59 | 2°63] 1°61 | 0°92 |..... 2°25 
 3 | Anthracite, South Wales... | 92°56 | 3°33} 2°53 /...../..... 1°58 
 4 | Caking Coal, Kentucky....| 74°45 | 4:93 | 13-08 | 1:03 | 0-91 | 5:00 
 5 | Caking Coal, Nelsonville, O.| 73°80 | 5-79 | 16°58 | 1:52 | 0:41 | 1°90 
 6 | Caking Coal, South Wales. .! 82°56 | 5°36 | 8:22 11:65 | 0:75! 1°46 
 7 | Caking Coal, Northumberl’d| 78°69 | 6:00 | 10:07 | 2°37 | 1:51 | 1:36 
 8 | Non-caking, Kentucky..... 7789 | 5°42 | 12°57! 1°82 | 3:00 | 2:00 
 9 | Non-caking “Black Coal,” | | g9-79 | 4-77 | 9:89 | 1-62,| 0:45 | 1-07 
 10 | Non-caking, Briar Hill, O.. | 78-94 | 5°92 | 11:50 | 1°58 | 0:56 | 1:45 
 11 | Non-caking, 8S. Staffordshire! 76°40 | 4°62 | 17°48 |..... 0°55 | 1:55 
 12 | Non-caking, Scotland...... 76°08 | 5°31 | 18°33 | 2:09 | 1:23 | 1:96 
 13 | Cannel Coal, Breckenridge. | 68°13 | 6:49 | 5°83 | 2°27 | 2°48 12°30 
 14 | Cannel Coal, Wigan....... 80°07 | 5:53 | 8°10 | 2°12 | 1°50 | 2°70 
 15 | Cannel Coal, ‘‘ Torbanite”. | 64:02 | 8-90 | 5°66 | 0:55 | 0:50 |20°32 
 16 | Albertite, Nova Scotia..... 86°04 | 8°96 | 1°97 | 2:93 | trace| 0:10 
 17 | Brown Coal, Bovey........ 66°31 | 5°63 | 22°86 | 0°57 | 2°36 | 2°27 
 18 | Brown Coal, Wittenberg... | 64:07 | 5:03 | 27°55 |.....)..... 3°30 
 19 | Peat,light brown (imperfect)| 50°86 | 5°80 | 42°57 | 0°77 |...../. 
 a0 Pent oere DCOWn....<..... 59°47 | 6°52 | 81:51 | 2°51 |..... 
 UY ET Dt) <a a ee 59°70 | 5°70 | 33:04 | 1:56 |..... 
 BE AG) DIAC lena sere esis ses OO TE Ly i214 toes theese an alee) ast, « 
 
 
 
 
 
 
 
 
 
 The coal, No. 4, from ‘‘ Roberts’ Seam,” Muhlenburg County, Ken- 
 tucky, has specific gravity—1:26 ; No. 9, from ‘* Wolf Hill,” Daviess 
 County, Indiana, has specific gravity =1°275. 
 
 No. 18, the Breckenridge cannel, of Hancock County, Kentucky, 
 consists, when the ash is excluded, of Carbon 82°36, hydrogen 7°84, 
 oxygen 7°05, nitrogen 2°75, and the Bog-head cannel of Scotland, called 
 also torbanite, contains Carbon 80°39, hydrogen 11:19, oxygen 7:11, ni. 
 trogen 1°31. 
 
 The ‘‘ Mineral Gharcoal ” of coal beds differs little in composition 
 from ordinary bituminous coal ; there is less hydrogen and oxygen. 
 Rowney obtained, for that of Glasgow and Fifeshire, Carbon 82:97, 
 74°71; hydrogen 3:34, 2°74; oxygen 7:59, 767; ash 6:08, 1486. The 
 nitrogen is included with the oxygen ; it was 0°75 in the Glasgow char- 
 coal. Exclusive of the ash; the composition is Carbon 88°36, 87°78 ; 
 hydrogen 3:56, 321; oxygen 7°28, 9°01. It has a fibrous look, and 
 occurs covering the surfaces between layers of coal, and has been ob- 
 served in coal of all ages. It is soft and soils the fingers like char- 
 coal ; one variety of it is a dry powder, 
 
300 DESCRIPTIONS OF MINERALS. 
 
 The following are average results, from many analyses : 
 
 a 
 
 
 
 —— 
 
 Vol. |Fixed 
 Nos.| Sp. gr. | com- | Car- Ash. Analysis. 
 bust. | bon. 
 
 
 
 
 
 
 
 S| ————— || 
 
 
 
 1 | Pennsylvania anthracites ~ 1459-161 | 3°92 | 89°77] 6°31 | Johnson. 
 ennsylvania anthracites...)| 46 |1:39-1-60 | 5°70 | 88°23 | 607| Geol. Survey. 
 
 2 | Pennsylvania,sgemicantbra ) a1 WSt-145.) 9 ie a Geol. Survey. 
 3 Reanne ree se ae 6 1:30-1:41 | 16°85 | 72°95 | 10°20 | Johnson. 
 
 
 
 Johnson and 
 
 
 
 
 
 4 | Maryland semi-bituminous...| 9 )1°80-1'43 15°50 | 74°03 | 10°47 | 4 “Geol. Survey. 
 5 | Pennsylvania bituminous.... RO) eecaceeiners 98:35 | 65°18 | 647| Johnson. 
 6 | Virginia bituminous....- ““""| 44 [1-29-1745 | 29°88 | 59°06 | 11-06 Johnson. 
 7 | Ohio bituminous.......-.---- 442 |1-24-1°47 | 35°24 | 60°26 | 4°50 Wormley. 
 8 | Indiana bituminous........--- 126 |1°19-1°41 | 43°20 | 53°47 | 3°33 Cox. 
 9 | Illinois bituminous.........-- 50 |1-21-1°35 | 81°90 | 62°44 | 5°66 Blaney. 
 410 | Iowa bituminous.........---- SOMME Aaeonme ipoaac: 43°02| 6°82 | Emery. 
 
 
 
 
 
 The ordinary impurities of coal, making up its ash, are silica, a 
 little potash and soda, and sometimes alumina, with often oxide of 
 iron, derived usually from sulphide of iron ; besides, in the less pure 
 kinds, more or less clay or shale. The amount of ash does not ordina- 
 rily exceed 6 per cent., but it is sometimes 80 per cent. ; and rarely it 
 is less than 2 per cent. When not over 3 or 4per cent. the whole may 
 have come from the plants which contributed the most of the material 
 of the coal, since the Lycopods have much alumina in the ash, and 
 the Equiseta much silica. 
 
 There is present in most coal traces of sulphide of iron (pyrite), suf- 
 ficient to give sulphur fumes to the gases from the burning coal, and 
 sometimes enough to make the coal valueless in metallurgical opera- 
 tions. Some thin layers are occasionally full of concretionary pyrite. 
 The sulphur was derived from the plants or from animal life in the 
 waters. Sulphur also occurs, in some coal beds, as a constituent of a 
 resinous substance ; and Wormley has shown that part of the sulphur 
 in the Ohio coals is in some analogous state, there being not iron 
 enough present to take the whole into combination. 
 
 The average amount of ash in eighty-eight coals from the southern 
 half of Ohio, according to Wormley, is 4718 per cent.; in sixty-six 
 coals from the northern half, 5°120; in all, from both regions, 4°891 ; 
 or, omitting ten, having more than ten per cent. of ash, the average is 
 428, In eleven Ohio cannels, the average amount of ash was 12°827. 
 The moisture in the Ohio coals, according to the analyses of Wormley, 
 varies from 1°10 to 9:10 per cent. of the coal. 
 
 Mineral coal occurs in extensive beds _ or layers, interstratified with 
 different rock strata. The associate rocks are usually clay shales (or 
 slaty beds) and sandstones ; and the sandstones are occasionally coarse 
 grit rocks or conglomerates. There are sometimes also beds of lime- 
 stone alternating with the other deposits. 
 
 Coal beds vary in thickness from a fraction of an inch to 40 feet. 
 The thickness of a bed may increase or diminish much in the course 
 of a few miles, or the coal may become too shaly to work, 
 
MINERAL COAL. 331 
 
 The areas of the ‘‘coal-measures” of the Carboniferous era, in 
 the United States, are as follows : 
 
 1. A small area in Rhode Island, continued northward into Massa- 
 chusetts, . 
 
 2. A large area in Nova Scotia and New Brunswick, stretching east- 
 ward and westward from the head of the Bay of Fundy. 
 
 These two areas are now separated ; but it is probable that they 
 were once united along the region, now submerged, of the Bay of 
 Fundy and Massachusetts Bay. . 
 
 3. The Alleghany Region, which commences at the north on the 
 southern borders of New York, and stretches southwestward across 
 Pennsylvania, West Virginia, and Tennessee to Alabama, and west- 
 ward over part of Eastern Ohio, Kentucky, Tennessee, and a small 
 portion of Mississippi. To the north, the Cincinnati ‘‘ uplift,” or 
 the Silurian area extending from Lake Erie over Cincinnati to Ten- 
 nessee, forms the western boundary. 
 
 4. The Michigan coal area, an isolated area wholly confined within 
 the lower peninsula of Michigan. 
 
 5. The Eastern Interior area, covering nearly two-thirds of Illinois, 
 and parts of Indiana and Kentucky. 
 
 6. The Western Interior area, covering a large part of Missouri, 
 and extending north into Iowa, and South, with interruptions, through 
 Arkansas into Texas, and west into Kansas and Nebraska. 
 
 The Ulinois and Missouri areas are connected now only through the 
 underlying Subcarboniferous rocks of the age ; but it is probable that 
 formerly the coal fields stretched across the channel of the Missis- 
 sippi, and that the present separation is due to erosion along the 
 valley. Rocks of the Carboniferous period extend over large portions 
 of the Rocky Mountain area, but they are mostly limestones, and are 
 barren of coal. 
 
 The extent of the coal-bearing area of these Carboniferous regions 
 is approximately as follows : 
 
 (UC CE 0 tsa i 500 square miles. 
 BE a a en ee 59,000 square miles. 
 APE BALOS 700, oy Filan ioe Su vce < dele eee ace 6,700 square miles. 
 Illinois, Indiana, West Kentucky...... 47,000 square miles. 
 Missouri, Iowa, Kansas, Arkansas, Texas 78,000 square miles. 
 Nova Scotia and New Brunswick....... 18,000 square miles. 
 
 The whole area in the United States is over 190,000 square miles, 
 and in North America about 208,000. Of the 190,000 square miles, 
 perhaps 120,000 have workable beds of coal. 
 
 Anthracite is the coal of Rhode Island, and of the areas in Central 
 Pennsylvania, from the Pottsville or Schuylkill coal field to the Lacka- 
 wanna field, while the coal of Pittsburg, and of all the great coal- 
 fields of the Interior basin, is bituminous, excepting a small area in 
 Arkansas. Anthracite belongs especially to regions of upturned 
 rocks, and bituminous coal to those where the beds are little disturbed. 
 In the area between the anthracite region of Central Pennsylvania 
 and the bituminous of Western, and farther south, the coal is semi- 
 bituminous, as in Broad Top, Pennsylvania, and the Cumberland coal 
 field in Western Maryland, the volatile matters yielded by it being 15 
 
332 DESCRIPTIONS OF MINERALS. 
 
 to 20 per cent. The more western parts of the anthracite coal fields 
 afford the free-burning anthracite, or semi-anthracite, as at Trevor- 
 ton, Shamokin, and Birch Creek. 
 
 The coal-formation of the Carboniferous age in Europe has great 
 thickness of rocks and coal in Great Britain, much less in Spain, 
 France, and Germany, and a large surface, with little thickness of 
 coal, in Russia. It exists, also, and includes workable coal-beds, in 
 China, and also in India and Australia ; but part of the formation in 
 these latter regions may prove to be Permian. No coal of this era has 
 yet been found in South America, ‘Africa, or Asiatic Russia. The pro- 
 portion of coal beds to area in different parts of Europe has been 
 stated as follows: in France, 1-100th of the surface ; in Spain, 1-50th; 
 in Belgium, 1-20th ; in Great Britain, 1-10th. But, while the coal 
 area in Great Britain is about 12,000 square miles, that of Spain is 
 4,000, that of France about 2,000, and that of Belgium 518. 
 
 Mineral coal of later age than the true Carboniferous era occurs in 
 various parts of the world. ‘Triassic or Jurassic coal, of the bitumi- 
 nous variety, occurs in thick workable beds in the vicinity of Rich- 
 mond, Virginia, and also in the Deep River and Dan River regions 
 in North Carolina; and_ it constitutes very valuable and extensive 
 beds also in India. In England, at Brora in Sutherlandshire, there 
 is a bed of Jurassic coal. Coal of the Cretaceous and Tertiary eras 
 constitutes important beds in various parts of the Rocky Mountain 
 region, in the vicinity of the Pacific Railroad and elsewhere. Some 
 of the prominent localities are : In Utah, at Evanston and Coalville 
 (in the valley of Weber River), etc.; in Wyoming, at Carbon, 140 
 miles from Cheyenne ; at Hallville, 142 miles farther west ; at Black 
 Butte Station, on Bitter Creek ; on Bear River, etc.; in the Uintah 
 Basin, near Brush Creek, 6 miles from Green River; in Colorado, at 
 Golden City, 15 miles west of Denver, on Ralston Creek, Coal Creek, 
 S. Boulder Creek and elsewhere ; in New Mexico, at the Old Placer 
 Mines in the San Lazaro Mountains, etc. The coal is of the bitumi- 
 nous or semibituminous kind, related to brown coal, and is often im- 
 properly called lignite. That of Evanston (where the bed is 26 feet 
 thick) afforded Prof. P. Frazier, Jr., 37-388 per cent. of volatile sub- 
 stances, 5-6 of water, _8 of ash, and 49-50 of fixed carbon. At the 
 Old Placer Mines, New Mexico, there is anthracite, according to Dr. 
 J. LeConte, affording 88 to 91 per cent. of fixed carbon ; specimens 
 from there, analyzed by Frazier, were semibituminous, affording 
 68-70 per cent. of fixed carbon, 20 per cent. of volatile substances, and 
 about 3 per cent. of water. The region of the Old Placer Mines is one 
 of upturned and altered rocks, like the anthracite region of Pennsyl- 
 vania. Other similar beds occur toward the Pacific coast, the most 
 valuable of them in Washington Territory, Seattle and Bellingham 
 Bay, and on Vancouver and adjacent islands in British Columbia, 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 333 
 
 I. CATALOGUE OF AMERICAN LOCALI- 
 TIES OF MINERALS. 
 
 THE following catalogue of American localities of minerals is intro- 
 duced as a Supplement to the Descriptions of Minerals. Its object is 
 to aid the mineralogical tourist in selecting his routes and arranging 
 the plan of his journeys. Only important localities, affording cabinet 
 specimens, are in general included ; and the names of those minerals 
 ahich are obtainable in good specimens are distinguished by italics. 
 When a name is not italicized the mineral occurs only sparingly or of 
 poor quality. When the specimens. to be procured are remarkably 
 good, an exclamation mark (!) is added, or two of those marks (! !) 
 when the specimens are quite unique. 
 
 AINE. 
 
 ee oe ! green and black tourmaline, feldspar, rose quartz, 
 rutile. 
 
 AROOSTOOK.—Red hematite. 
 
 AUBURN.—Lepidolite, hebronite, green tourmaline. 
 
 BatTu.—Vesuvianite, garnet, magnetite, graphite. 
 
 BETHEL.—Cinnamon garnet, calcite, sphene, beryl, pyroxene, horn- 
 blende, epidote, graphite, talc, pyrite, arsenopyrite, magnetite, wad. 
 
 BINGHAM.—WMassive pyrite, galenite, blende, andalusite. 
 
 BuiuE Hitt Bay.—Arsenical iron, molybdenite! galenite, apatite! 
 fluorite! black tourmaline (Long Cove), black oxide of manganese 
 (Osgood’s farm), rhodonite, bog manganese, wolframite. 
 
 Bowvoin.— Lose quartz. 
 
 BowpboinHamM.— Beryl, molybdenite. 
 
 BRUNSWICK.—Green mica, garnet ! black tourmaline! molybdenite, 
 epidote, calcite, muscovite, feldspar, beryl. 
 
 BUCKFIELD.—Garnet (estates of Waterman and Lowe), muscovite / 
 tourmaline! magnetite. 
 
 CAMDAGE FArM.—(Near the tide mills), molybdenite, wolframite. 
 
 CAMDEN.—WMacle, galenite, epidote, black tourmaline, pyrite, talc, 
 magnetite. . 
 
 CARMEL (Penobscot Co.)—Stibnite, pyrite, macle. 
 
 CoRINNA.—Pyrite, arsenopyrite. 
 
 DEER ISLE.—Serpentine, verd-antique, asbestus, diallage. 
 
 DEXTER.—Galenite, pyrite, blende, chalcopyrite, green talc. 
 
 _ DIXFIELD.—Native copperas, graphite. 
 
 East Woopstock.—Muscovite. 
 
 FARMINGTON.—(Norton’s Ledge), pyrife, graphite, garnet, staurolite. 
 
 FREEPORT.—Lvose quartz, garnet, feldspar, scapolite, graphite, mus- 
 covite. 
 
 FrYEBURG.— Garnet, beryl. 
 
 GEORGETOWN. —(Parker’s Island), beryl / black tourmaline. 
 
304 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 GREENWOOD.—Graphite, black manganese, beryl ! arsenopyrite, 
 cassiterite, mica, rose quartz, garnet, corundum, albite, zircon, molyb- 
 denite, magnetite, copperas. 
 
 HEBron.—Cassiterite, arsenopyrite, idocrase, lepidolite, hebroniie, 
 rubellite | indicolite, green tourmaline, mica, beryl, apatite, albite, chil- 
 drenite, cookeite. 
 
 JEWELL’S IsLAND.—Pyrite. 
 
 KATAHDIN IRon Works.—Bog-iron ore, pyrite, magnetite, quartz. 
 
 LITCHFIELD.—Sodalite, cancrinite, elwolite, zircon, Spodumene, mus- 
 covite, pyrrhotite. 
 
 Luprec Leap Mines.—Galenite, chalcopyrite, blende. 
 
 MACHIASPORT. —Jasper, epidote, laumontite. 
 
 MADAWASKA SETTLEMENTS.— Vivianite. 
 
 Mrnot.—Beryl, smoky quarté. 
 
 Monmovutu.—Actinolite, apatite, elwolite, zircon, staurolite, plumose 
 mica, beryl, rutile. 
 
 Mr. ABRAHAM.—Andalusite, staurolite. ‘ 
 
 Norway.—Onrysoberyl / molybdenite, beryl, rose quartz, orthoclase, 
 cinnamon garnet. 
 
 OrR’s ISLAND. —Steatite, garnet, andalusite. 
 
 OxForD.—Garnet, beryl, apatite, wad, zircon, muscovite, orthoclase. 
 
 Paris.—Green! red! black, and blue tourmaline! mica ! lepidolite / 
 feldspar, albite, quartz crystals | rose quartz, cassiterite, amblygonite, 
 zircon, brookite, beryl, smoky quartz, spodumene, cookeite, leucopy- 
 rite. 
 
 PARSONSFIELD.— Vesuvianite! yellow garnet, pargasite, adularia, 
 scapolite, galenite, blende, chalcopyrite. 
 
 Prervu.—Crystallized pyrite. 
 
 Purepspure. — Yellow garnet ! manganesian garnet, vesuvianite, par- 
 gasite, axinite, laumontite! chabazite, an ore of cerium ? 
 
 POLAND.—Vesuvianite, smoky quartz, cinnamon garnet. 
 
 PorTLAND.—Prehnite, actinolite, garnet, epidote, amethyst, calcite. 
 
 PownaL.—Black tourmaline, feldspar, scapolite, pyrite, actinolite, 
 apatite, rose quartz. 
 
 RayMonp.— Magnetite, scapolite, pyroxene, lepidolite, tremolite, horn- 
 blende; epidote, orthoclase, yellow garnet, pyrite, vesuvianite. 
 
 RoOcKLAND.—Hematite, tremolite, quartz, wad, tale. 
 
 RuMFORD.— Yellow garnet, vesuvianite, pyroxene, apatite, scapolite. 
 
 RuTLAND.—Allanite. 
 
 Sanpy RrveR.—Auriferous sand. 
 
 SANFORD, York Co.— Vesuvianite / albite, calcite, molybdenite, epi- 
 dote, black tourmaline, labradorite. 
 
 SraRsMoNnT.—Andalusite, tourmaline. 
 
 SourH BERwicK.—Macle. 
 
 STranDIsH.—Columbite ! 
 
 STREAKED MountTAIn.—Beryl / black tourmaline, mita, garnet. 
 
 THOMASTON.—Calcite, tremolise, hornblende, sphene, arsenical iron 
 (Owl’s Head), black manganese (Dodge’s Mountain), thomsonite, tale, 
 blende, pyrite, galenite. 
 
 TorpsHAM.—Quartz, galenite, blende, tungstite? beryl, apatite, 
 molybdenite, columbite. 
 
 Wa.Es.—Axinite in boulder, alum, copperas, 
 
 WATERVILLE.—Crystallized pyrite. 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. Oba 
 
 WINDHAM (near the bridge).—Stawrolite, spodumene, garnet, beryl, 
 amethyst, cyanite, tourmaline. 
 
 WINSLOW.—Cassiterite. 
 
 WInTHROP.—Staurolite, pyrite, hornblende, garnet, copperas. 
 
 W oopstock.—Graphite, hematite, prehnite, epidote, calcite. 
 
 YorkK.—Seryl, vivianite, oxide of manganese, 
 
 NEW IAMPSHUIRE. 
 
 AcwortH.—Beryl!! mica! tourmaline, orthoclase, albdite, rose 
 quartz, columbite / cyanite, autunite. 
 
 ALSTEAD.—Mica!! albite, black tourmaline, molybdenite, andalu- 
 site, staurolite. 
 
 AMHERST.— Vesuvianite, yellow garnet, pargasite, calcite, amethyst. 
 
 BARTLETT.—Magnetite, hematite, smoky quartz. 
 
 Batu. —Galenite, chalcopyrite. 
 
 BEDFORD.—Tremolite, epidote, graphite, mica, tourmaline, alum, 
 quartz. . 
 
 BELLOWS FALLS.—Cyanite, staurolite, wavellite. 
 
 BRISTOL.—Graphite. 
 
 CAaMPTON.—Beryl ! 
 
 CANAAN.—Gold in pyrite, garnet. 
 
 CHARLESTON.—Staurolite imacie, andalusite macle, bog-iron ore, 
 prehnite, cyanite. 
 
 CoRNISH.—AStibnite, tetrahedrite, rutile in quartz! (rare), staurolite. 
 
 CrOYDEN.—LJolite/ chalcopyrite, pyrite, pyrrhotite, blende. 
 
 ENFIELD.—Gold, galenite, staurolite, green quartz. 
 
 ' FRANCESTON.—Soapstone, arsenopyrite, quartz crystals. 
 
 FrRANcONIA.—Hornblende, staurolite! epidote ! zoisite, hematite, 
 magnetite, black and red manganesian garnets, arsenopyrite (danaite), 
 chalcopyrite, molybdenite, prehnite, green quartz, malachite, azurite. 
 
 GILFORD (Gunstock Mt.)—Magnetic iron ore, native ‘‘ lodestone.” 
 
 GILMANTOWN.—Tremolite, epidote, muscovite, tourmaline, limonite, 
 red and yellow quartz crystals. 
 
 GosHEN.—Graphite, black tourmaline. 
 
 GRAFTON.— Mica! (extensively quarried at Glass Hill, 2 m. S. cf 
 Orange Summit), albite/ blue, green, and yellow beryis/ (1 m. S. of O. 
 Summit), tourmaline, garnets, triphylite, apatite, fluorite. 
 
 GRANTHAM.—(Gray staurolite / 
 
 Groton.—Arsenopyrite, blue beryl, muscovite crystals. 
 
 HANOVER.—Garnet, black tourmaline, quartz, cyanite, labradorite, 
 epidote, anorthite. 
 
 HAVERHILL.—Garnet! arsenopyrite, native arsenic, galenite, blende, 
 pyrite, chalcopyrite, magnetite, marcasite, steatite. 
 
 HILLsBoro’ (Campbell’s Mountain).—Graphite. 
 
 HinsDALE.—Rhodonite, black oxide of manganese, molybdenite, in- 
 dicolite, black tourmaline, 
 
 JACKSON.—Drusy quartz, tin ore, arsenopyrite, native arsenic, fluo- 
 rite, apatite, magnetite, molybdenite, wolframite, chalcopyrite. 
 
 JAFFREY (Monadnock Mt.)—Cyanite, limonite. 
 
 KEENE.—Graphite, soapstone, milky quartz, rose quartz, 
 
 LANDAFF,—WMolybdenite, lead and iron ores, 
 
336 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 LEBANON.—Bog-iron ore, arsenopyrite, galenite, magnetite, pyrite. 
 
 Lispon.—Staurolite, black and red garnets, magnetite, hornblende, 
 epidote, zorsite, hematite, arsenopyrite, galenite, gold, ankerite. 
 
 Lirrneron.—Ankerite, gold, bornite, chalcopyrite, malachite, me- 
 naccanite, chlorite. 
 
 LyMAN.—Gold, arsenopyrite, ankerite, dolomite, galenite, pyrite, 
 copper, pyrrhotite. 
 
 LymE.—Oyanite (N. W. part), black tourmaline, rutile, pyrite, chal- 
 copyrite (E. of E. village), stibnite, molybdenite, cassiterite. 
 
 Maptson.—Galenite, blende, chalcopyrite, limonite. 
 
 Mrrrmack.—Rutile/ (in gneiss nodules in granite vein). 
 
 MIDDLETOWN. —fuiile. 
 
 Monapnock Mounrain.—Andalusite, hornblende, garnet, graphite, 
 tourmaline, orthoclase. t 
 
 MoostLaAvKE Mr.—Tourmaline. 
 
 MovLTonBorouGH (Red Hill).—Hornblende, bog ore, pyrite, tour- 
 maline. 
 
 NEwInetTon.—Garnet, tourmaline. 
 
 Nuw Lonpon.—Beryl, molybdenite, muscovite crystals. 
 
 NeEwrort.—Molybdenite. 
 
 ORANGE.—Blue beryls/ Orange Summit, chrysoberyl, mica (W. side 
 of mountain), apatite, galenite, limonite. 
 
 OrFORD.——Brown tourmaline (now obtained with difficulty), steatite, 
 rutile, cyanite, brown iron ore, native copper, malachite, galenite, 
 garnet, graphite, molybdenite, pyrrhotite, melaconite, chalcocite, ripi- 
 dolite. 
 
 PELHAM.—<Steatite. 
 
 PIERMONT.—Micaceous iron, barite, green, white, and brown mica, 
 apatite, titanic iron. 
 
 PLymMouTH.—Columbite, beryl. . 
 
 Ricumonp.—lJolite/ rutile, steatite, pyrite, anthophyllite, talc. 
 
 RyxE.—Chiastolite. 
 
 SADDLEBACK Mt.—Black tourmaline, garnet, spinel. 
 
 SHELBURNE.—Galenite, black blende, chalcopyrite, pyrite, pyrolusite. 
 
 SpRINGFIELD.—Beryls (very large, eight inches diameter), manga- 
 nesian garnets! black tourmaline! in mica slate, albite, mica. 
 
 SuLLIVAN.— Tourmaline (black) in quartz, beryl. 
 
 SurREY.—Amethyst, calcite, galenite, limonite, tourmaline. 
 
 TAMWORTH (near White Pond).—Galenite. 
 
 Unity (estate of James Neal).—Copper and tron pyrites, chlorophyl- 
 lite, green mica, radiated actinolite, garnet, titaniferous tron ore, mag- 
 netite, tourmaline. 
 
 WALPOLE (near Bellows Falls),—Macle, staurolite, mica, graphite. 
 
 W aArE.—Graphite. 
 
 WARREN.—Chalcopyrite, blende, epidote, quartz, pyrite, tremolite, 
 galenite, rutile, tale, molybdenite, cinnamon stone ! pyroxene, horn- 
 blende, beryl, cyanite, tourmaline (massive) vesuvianite. 
 
 W ATERVILLE.—Labradorite, chrysolite. 
 
 WESTMORELAND (south part).—Molybdenite ! apatite ! blue feldspar, 
 bog manganese (north village), quartz, fluorite, chalcopyrite, molybdite. 
 
 WuitsE Mrs. (Notch near the «‘Crawford House”).—Green octa- 
 hedral fluorite, quartz crystals, black tourmaline, chiastolite, beryl, 
 calcite, amethyst, amazon-stone, ; 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 337 
 
 Wiimor.—Bery/. 
 WINCHESTER.—Pyrolusite, rhodonite, rhodochrosite, psilomelane, 
 magnetite, granular quartz, spodumene. 
 
 VERMONT. 
 
 ApDpIson.—J/ron sand, pyrite. 
 
 ATHENS.—Steatite, rhomb spar, actinolite, garnet. 
 
 BALTIMORE.—Serpentine, pyrite! 
 
 BELVIDERE.—Steatite, chlorite. 
 
 BENNINGTON. —Pyrolusite, brown iron ore, pipe clay, yellow ochre. 
 
 BERKSHIRE.—/pidote, hematite, magnetite. 
 
 BETHEL.— Actinolite! talc, chlorite, octahedral iron, rutile, brown 
 spar in steatite. 
 
 BRANDON.—Braunite, pyrolusite, psilomelane, limonite, lignite, 
 kaolinite, statuary marble; graphite, chalcopyrite. 
 
 BRATTLEBOROUGH.—Black tourmaline in quartz, mica, zoisite, Tu- 
 tile, actinolite, scapolite, spodumene, roofing slate. 
 
 BRIDGEWATER.—TZalc, dolomite, magnetite, steatite, chlorite, gold, 
 native copper, blende, galenite, blue spinel, chalcopyrite. 
 
 BRISTOL.— Rutile, limonite, manganese ores, magnetite. 
 
 BROOKFIELD.—Arsenopyrite, pyrite. 
 
 CABOT.—Garnet, staurolite, hornblende, albite. 
 
 CASTLETON.— Roofing slate, jasper, manganese ores, chlorite. 
 
 CAVENDISH.—Garnet, serpentine, talc, steatite, tourmaline, asbestus, 
 tremolite. 
 
 CHESTER.— Asbestus, feldspar, chlorite, quartz. 
 
 CHITTENDEN.—Psilomelane, pyrolusite, brown iron ore, hematite 
 and magnetite, galenite, iolite. 
 
 COLCHESTER. —Brown iron ore, iron sand, jasper, alum. 
 
 CoRINTH. —Chalcopyrite (has been mined), pyrrhotite, pyrite, rutile. 
 
 COVENTRY.— Rhodonite. 
 
 CRAFTSBURY.—Mica in concentric balls, calcite, rutile. 
 
 DERBY.—Mica (adamsite). 
 
 DUMMERSTON.—Rutile, roofing slate. 
 
 Farr HAven.— Roofing slate, pyrite. 
 
 FLETCHER.—Pyrite, magnetite, acicular tourmaline. 
 
 GRAFTON.—The steatite quarry referred to Grafton is properly in 
 Athens ; quartz, actinolite. 
 
 GUILFORD.—Scapolite, rutile, roofing slate. 
 
 HARTFORD.—Calcite, pyrite! cyanite, quartz, tourmaline. 
 
 JRASBURGH.—Rhodonite, psilomelane. 
 
 JAY.—Chromite, serpentine, amianthus, dolomite. 
 
 LOWELL.—Picrosmine, amianthus, serpentine, talc, chlorite. 
 
 MARLBORO’.—Rhomb spar, steatite, garnet, magnetite, chlorite. 
 
 MIDDLEBURY.—Zircon. 
 
 MIDDLESEX.—Rutile ! (exhausted). 
 
 MonxkTown.—Pyrolusite, brown iron ore, pipe clay, feldspar. 
 
 MoRETOWN.—Smoky quartz! steatite, talc, wad, rutile, serpentine. 
 
 MoRRISTOWN.—Galenite. 
 
 Mount Houuiy.—Asbestus, chlorite. 
 
 Nrw Fang. —Glassy and asbestiform actinolite, steatite, green quartz 
 
 22 
 
338 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 (called chrysoprase at the locality), chalcedony, drusy quartz, garnet, 
 chromic and titanic iron, rhomb spar, serpentine, rutile. 
 
 Norwicu.—Actinolite, feldspar, brown spar, in talc, cyanite, zoisite, 
 chalcopyrite, pyrite. 
 
 PrrrsFoRD.—Brown iron ore, manganese Ores, statuary marble | 
 
 PLYMOUTH.—Siderite, magnetite hematite, gold, galenite. 
 
 PLymMptTon.—Massive hornblende. 
 
 SARE! ci a limonite, rutile, and zoisite, in boulders, stau- 
 rolite. 
 
 READING.—Glassy actinolite in talc. 
 
 READsBoRO’.—Glassy actinolite, steatite, hematite. 
 
 Rieron.—Brown iron ore, augite in boulders, octahedral pyrite. 
 
 RocuEster.—Rutile, hematite cryst., magnetite in chlorite slate. 
 
 RockrneHam (Bellows Falls).—Cyanite, indicolite, feldspar, tour- 
 maline, fluorite, calcite, prehnite, staurolite. 
 
 Roxpury.— Dolomite, talc, serpentine, asbestus, quartz. 
 
 RutTLAND.—Magnesite, white marble, hematite, serpentine, pipe clay. 
 
 SALISBURY.—Brown iron ore. 
 
 Sparon.—Quartz crystals, cyanite. 
 
 SHOREHAM.—Pyrite, black marble, calcite. 
 
 SHREWSBURY.—Magnetite and chalcopyrite. 
 
 SrrRLInG. —Chalcopyrite, talc, serpentine. 
 
 SrOCKBRIDGE.—Arsenopyrite, magnetite. 
 
 STRAFFORD.—Magnetite and chalcopyrite (has been worked), native 
 copper, hornblende, copperas. 
 
 THETFORD.—Blende, galenite, cyanite, chrysolite in basalt, pyrrho- 
 tite, feldspar, roofing slate, steatite, garnet. 
 
 TOWNSHEND.—Actinolite, black mica, talc, steatite, feldspar. 
 
 Troy.—Magnetite, tale, serpentine, picrosmine, amianthus, steatite, 
 one mile southeast of village of South Troy, on the farm of Mr. Pierce, 
 cast side of Missisco, chromite, zaratite.. 
 
 Vursurre.— Pyrite, chalcopyrite, tourmaline, arsenopyrite, quartz, 
 
 W ARDsBoRO’.—Zoisite, tourmaline, tremolite, hematite. 
 
 WARREN.—Actinolite, magnetite, wad, serpentine. 
 
 WATERBURY.—Arsenopyrite, chalcopyrite, rutile, quartz, serpen- 
 tine. 
 
 W ATERVILLE.—<Steatite, actinolite, tale. 
 
 WEATHERSFIELD.—Steatite, hematite, pyrite, tremolite. 
 
 WELL’ R1veR.—Graphite. 
 
 WESsTFIELD.—Steatite, chromite, serpentine. 
 
 WESTMINSTER.—Zoisite in boulders. 
 
 WinpHAM.—Glassy actinolite, steatite, garnet, serpentine. 
 
 Wooppury.—Massive pyrite. 
 
 Woopstock.—Quarte crystals, garnet, zoisite. 
 
 MASSACHUSETTS. 
 
 ALFoRD.—Galenite, pyrite. 
 ArnoL.—Allanite, fibrolite (%), epidote / babingtonite ? 
 AuBURN.—Masonite. 
 BaRRE.—Rutile ! mica, pyrite, beryl, feldspar, garnet. 
 GREAT BARRINGTON. — Tremolite. 
 
 BEDFORD. —Carnet, 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 339 
 
 BELCHERTON.—Allanite. 
 
 BERNARDSTON.—Magnetite. 
 
 BEVERLY.—Columbite, green feldspar, cassiterite. 
 
 BLANFORD.—Serpentine, anthophyllite, actinolite ! chromite, cyanite, 
 rose quartz in boulders, 
 
 Bouton.—Scapolite! petalite, sphene, pyroxene, nuttalite, diopside, 
 boltonite, apatite, magnesite, rhomb spar, allanite, yttrocerite / spinel. 
 
 BoxBoRrouGcH.—Scapolite, spinel, garnet, augite, actinolite, apatite. 
 
 BRIGHTON.—Asbestus. 
 
 BRIMFIELD (road leading to Warren).—Jolite, adularia, molybdenite, 
 mica, garnet. 
 
 CARLISLE.— Tourmaline, garnet ! scapolite, actinolite. 
 
 CHARLESTOWN.—Prehnite, laumontite, stilbite, chabazite, quartz 
 crystals, melanolite. 
 
 CHELMSFORD.—Scapolite (chelmsfordite), chondrodite, blue spinel, 
 amianthus / rose quartz. 
 
 CHESTER.—Hornblende, scapolite, zoisite, spondumene, indicolite, 
 apatite, magnetite, chromite, stilbite, heulandite, analcite and cha- 
 bazite. At the Emery Mine, Chester Factories.—Oorundum, marga- 
 ‘rite, diaspore, epidote, corundophilite, chloritoid, tourmaline, menac- 
 canite! rutile, biotite, indianite ? andesite? cyanite, amesite. 
 
 CHESTERFIELD.— Blue, green, and red tourmaline, cleavelandite 
 (albite), lepidolite, smoky quartz, microlite, spodumene, cyanite, apatite, 
 rose beryl, garnet, quartz crystals, staurolite, cassiterite, colwmbite, 
 zoisite, uranite, brookite (eumanite), scheelite, anthophyllite, bornite. 
 
 Conway.—Pyrolusite, fluorite, zoisite, rutile // native alum, gale- 
 nite. 
 
 CuMMINGTON.—Rhodonite/ cummingtonite (hornblende), marcasite, 
 garnet. 
 
 DEERFIELD.—Chabazite, heulandite, stilbite, amethyst, carnelian, 
 chalcedony, agate. 
 
 FircHBure (Pearl Hill).—Beryl, staurolite! garnets, molybdenite. 
 
 FoxporovueH.—Pyrite, anthracite. 
 
 FRANKLIN.—Amethyst. 
 
 GosHEN.—WMica, albite, spondumene! blue and green tourmaline, 
 beryl, zoisite, smoky quartz, columbite, tin ore, galenite, beryl (go- 
 shenite), cymatolite. 
 
 GREENFIELD (in sandstone quarry, half mile east of village).—Allo- 
 phane, white and greenish. 
 
 HATFIELD.—Barite, galenite, blende, chalcopyrite. 
 
 Haw LEy.— Micaccous iron, massive pyrite, magnetite, zoisite. : 
 
 HEATH. — Pyrite, zoisite. 
 
 HinsDALE.—Brown iron ore, apatite, zoisite. 
 
 HUBBARDSTON.— Massive pyrite. 
 
 HUNTINGTON (name changed from Norwich) —Apatite ! black tour- 
 maline, beryl, spodumene! triphylite (altered), blende, quartz crystals, 
 cassiterite. 
 
 ; LANCASTER.—Cyanite, chiastolite! apatite, staurolite, pinite, anda- 
 usite. 
 
 LrEe.—Tremolite! sphene ! (east part). 
 
 LEVERETT.—Barite, galenite, blende, chalcopyrite. 
 
 LEYDEN.—Zoisite, rutile. 
 
 LITTLEFIELD.—Spinel, scapolite, 
 
340 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 LYNNFIELD.—Magnesite on serpentine. 
 
 Mrnpon.—WMica/ chlorite. 
 
 MIDDLEFIELD. —Glassy actinolite, rhomb spar, steatite, serpentine, 
 feldspar, drusy quartz, apatite, zoisite, nacrite, chalcedony, talc / 
 deweylite. 
 
 Mitsury.— Vermiculite. 
 
 New BRAINTREE.—Black tourmaline. 
 
 NEWBURY.—Serpentine, chrysotile, epidote, massive garnet, side- 
 rite. 
 
 NEWBURYPORT.—Serpentine, nemalite, uranite.—Argentiferous ga- 
 lenite, tetrahedrite, chalcopyrite, pyrargyrite, etc. 
 
 NoRTHFIELD.—OColumbite, fibrolite, cyanite. 
 
 Norwicu.—See HUNTINGTON. 
 
 PALMER (Three Rivers).— feldspar, calcite. 
 
 PELHAM. —Asbestus, serpentine, quartz crystals, beryl, molybdenite, 
 green hornstone, epidote, amethyst, corundum, vermiculite (pelhamite). 
 
 PLAINFIELD.—Cummingtonite, pyrolusite, rhodonte. 
 
 RICHMOND.—Brown iron ore, gibbsite ! allophane. 
 
 Rockport.— Danalite, eryophyllite, annite, cyrtolite (altered zircon), 
 green and white orthoclase, fergusonite. 
 
 RowE.—Fpidote, tale. 
 
 Sourn RoyaLston.—Beryl / / (aow obtained with great difficulty), 
 mica! ! feldspar! allanite. Four miles beyond old loc., on farm of 
 Solomon Heywood, mica! beryl ! feldspar | menaccanite. 
 
 RussEL.—Schiller spar (diallage ?), mica, serpentine, beryl, galenite, 
 chalcopyrite. 
 
 SaLEM.—In a boulder, cancrinite, sodalite, elzeolite. 
 
 SHEFFIELD.—Asbestus, pyrite, native alum, pyrolusite, rutile. 
 
 SHELBURNE.—Rutile, 
 
 SHUTESBURY (east of Locke’s Pond).—Molybdenite. 
 
 SouTHAMPTON .—Galenite, cerussite, anglesite, wulfenite, fluorite, 
 barite, pyrite, chalcopyrite, blende, phosgenite, pyromorphite, stolzite, 
 chrysocolla. 
 
 SrERLING.—Spodumene, chiastolite, siderite, arsenopyrite, blende, 
 galenite, chalcopyrite, pyrite, sterlingite (damourite). 
 
 STONEHAM.—Wephrite. 
 
 STURBRIDGE.—G@raphite, garnet, apatite, bog ore. 
 
 Swampscor.—Orthite, feldspar. 
 
 TAUNTON (one mile south).—Paracolumbite (titanic iron). 
 
 TURNER’S FALLS (Conn. River).—Chalcopyrite, prehnite, chlorite, 
 siderite, malachite. 
 
 T'YRINGHAM.—Pyroxene, scapolite. 
 
 UxBRIDGE.—Galenite. 
 
 Warwick.—WMassive garnet, radiated black tourmaline, magnetite, 
 beryl, epidote. ' 
 
 W asHineton.—Graphite. 
 
 WESTFIELD.—Schiller spar (diallage), serpentine, steatite, cyanite, 
 scapolite, actinolite. 
 
 Westrorp.—Andalusite / 
 
 Wrst Hampron.—Galenite, argentine, pseudomorphous quart. 
 
 West SPRINGFIELD.—Prehnite, ankerite, satin spar, celestite. 
 
 West STocKkBRIDGE.-—Limonite, fibrous pyrolusite, siderite. 
 
 WHATELY.—JVative copper, galenite. 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 341 
 
 WILLIAMSBURG.—Zoisite, pseudomorphous quartz, apatite, rose and 
 smoky quartz, galenite, pyrolusite, chalcopyrite. 
 
 WILLIAMSTOWN.—Cryst. quartz. 
 
 WINDSOR.—Zoisite, actinolite, rutile / 
 
 WORCESTER. —Arsenopyrite, idocrase, pyroxene, garnet, amianthus, 
 bucholzite, siderite, galenite. 
 
 WORTHINGTON. —Cyanite. 
 
 ZOAR.—Bitter spar, tale. 
 
 RHODE ISLAND. 
 
 BRISTOL.— Amethyst. 
 
 COVENTRY.—Mica, tourmaline. 
 
 CRANSTON.—Actinolite in talc, graphite, cyanite, mica, melanterite. 
 
 CUMBERLAND.— Manganese, epidote, actinolite, garnet, titaniferous 
 iron, magnetite, red hematite, chalcopyrite, bornite, malachite, azu- 
 rite, calcite, apatite, feldspar, zoisite, mica, quartz crystals, ilvaite. 
 
 DriAMoND HILu.— Quartz crystals, hematite. 
 
 FostER.—Cyanite, hematite. 
 
 GLOUCESTER.— Magnetite in chlorite slate, feldspar. 
 
 JOHNSTON.—Talc, brown spar, calcite, garnet, epidote, pyrite, he- 
 matite, magnetite, chalcopyrite, malachite, azurite. 
 
 Natic.—See WARWICK. 
 
 NEwrPort.—Serpentine, quartz crystals. 
 
 PoRTSMOUTH.— Anthracite, graphite, asbestus, pyrite, chalcopyrite. 
 
 SMITHFIELD.— Dolomite, calcite, bitter spar, siderite, nacrite, serpen- 
 tine (bowenite), tremolite, asbestus, quartz, magnetic iron in chlorite 
 slate, tale / octahedrite, feldspar, beryl. 
 
 VALLEY Fauus.—Graphite, pyrite, hematite. 
 
 WARWICK (Natic village).— Masonite, garnet, graphite. 
 
 W ESTERLY.—Menaccanite. 
 
 WOONSOCKET.—Cyanite. 
 
 CONNECTICUT 
 
 BERLIN.—Barite, datolite, blende, quartz crystals. 
 
 Bo.tton.—Staurolite, chalcopyrite. 
 
 BRADLEYVILLE (Litchfield),—Laumontite. 
 
 BristoL.—Chalcocite, chalcopyrite, barite, bornite, allophane, pyro- 
 morphite, calcite, malachite, galenite, quartz, 
 
 BROOKFIELD.—Galenite, calamine, blende, spodumene, pyrrhotite. 
 
 CaNAAN.—Tremolite and white augite / in dolomite, canaanite (mas- 
 sive pyroxene). 
 
 CHATHAM.—Arsenopyrite, smaltite, cloanthite (chathamite), scoro- 
 dite, niccolite, beryl, erythrite. 
 
 CHESHIRE.—Barite! chalcocite, bornite, malachite, kaolin, natrolite, 
 prehnite, chabazite, datolite. 
 
 CHESTER.—Sillimanite / zircon, epidote. 
 
 CORNWALL.— Graphite, pyroxene, actinolite, sphene, scapolite. 
 
 DANBURY. —Danburite, oligoclase, moonstone, brown tourmaline, 
 orthoclase, pyroxene, parathorite. 
 
 FARMINGTON.—Prehnite, chabazite, agate, native copper; in trap, 
 diabantite. 
 
342 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.” 
 
 Granpy.—Green malachite. 
 
 Greenwicu.— Black tourmaline. 
 
 Happam.—Chrysoberyl! beryl ! epidote ! tourmaline ! feldspar, gar- 
 net! tolite! oligoclase, chlorophyllite ! automolite, magnetite, adularia, 
 apatite, columbite / (hermannolite), zircon (calyptolite), mica, pyrite, 
 marcasite, molybdenite, allanite, bismuth ochre, bismutite. 
 
 HADLYME.—Chabazite and stilbite in gneiss with epidote and gar- 
 net. 
 
 Hartrorp.—Datolite (Rocky Hill quarry). 
 
 Kernr.—Limonite, pyrolusite. 
 
 LitcHFIEitp.—Cyanite with corundum, apatite, and andalusite, me- 
 naccanite (washingtonite), chalcopyrite, diaspore, niccoliferous pyrrhe- 
 tite, margarodite. 
 
 LymeE.——Garnet, sunstone. — 
 
 MIDDLEFIELD Fauus.—Datolite, chlorite, etc., in amygdaloid. 
 
 MippLetown.—Mica, lepidolite with green and red tourmaline, 
 albite, feldspar, columbite ! prehnite, garnet (sometimes octahedral), 
 beryl, topaz, uranite, apatite, pitchblende ; at lead mine, galenite, chal- 
 copyrite, blende, quartz, calcite, fluorite, pyrite sometimes capillary. 
 
 MILFORD.—Sahlte, pyrovene, asbestus, zoisite, verd-antique, marble, 
 pyrite. 
 
 New Haven.—Serpentine, sahlite, stilbite, prehnite, chabazite, 
 Jaumontite, gmelinite, apophyllite, topazolite. 
 
 NEewtTown.—Cyanite, diaspore, rutile, damourite, cinnabar. 
 
 Norwicu. —Sillimanite, monazite/ tolite, corundum, feldspar. 
 
 OXFORD (near Humphreysville).—Cyanite, chalcopyrite. 
 
 PoRTLAND.—Orthoclase, albite, muscovite, biotite, beryl, tourmaline, 
 columbite, apatite. 
 
 PLymMoutTH.—Galenite, heulandite, fluorite, chloryphyllite! garnet. 
 
 REDDING (near the line of Danbury).—Pyroxene, garnet. Near 
 Branchville R. R. depot: Albite, microcline, hebronite, spodumene f 
 cymatolite, damourite, eosphorite, triploidite, reddingite, dickinsonite, 
 lithiophilite, rhodochrosite, fairfieldite, apatite, microlite, columbite, 
 garnet, pyrite, tourmaline, staurolite, uraninite, torbernite, autunite, 
 vivianite. 
 
 Roartnc Brook (Cheshire).—Datolite ! calcite, prehnite, saponite. 
 
 Roxpury.—ASiderite, blende, pyrite ! 1 galenite, quartz, chalcopyrite, 
 arsenopyrite, limonite. 
 
 SALISBURY.—Limonite, pyrolusite, triplite, turgite. 
 
 SayprooKk.—Molybdenite, stilbite, plumbago. 
 
 Spymour.—Native bismuth, arsenopyrite, pyrite. 
 
 SrusBury.—Copper glance, green malachite. 
 
 SouTHBURY.—Rose quartz, laumontite, prehnite, calcite, barite. 
 
 SouTHINGTON.—Barite, datolite, asteriated quartz crystals. 
 
 STAFFORD. —Massive pyrites, alum, copperas. 
 
 STONINGTON.—Stilbite and chabazite on gneiss. 
 
 TARIFF VILLE. —Datolite. 
 
 THATCHERSVILLE (near Bridgeport).—Stilbite on gneiss, babing- 
 tonite? 
 
 ToLLAND.—Staurolite, massive pyrites. 
 
 TRUMBULL and MonroE.—Chlorophane, topaz, beryl, diaspore, pyl- 
 rhotite, pyrite, niccolite, scheelite, wolframite (pseudomorph of scheel- 
 ite), rutile, native bismuth, tungstic acid, siderite, arsenopyrite, 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 343 
 
 argentiferous galenite, blende, scapolite, tourmaline, garnet, albite, 
 augite, graphic tellurium (?), margarodite. 
 WASHINGTON. —Zripolite, menaccanite / (washingtonite of Shepard), 
 rhodochrosite, natrolite, andalusite (New Preston), cyanite. 
 WATERTOWN, near the Naugatuck.—White sahlite, monazite. 
 West Farms.—Asbestus. 
 WILLIMANTIC.— Topaz, monazite, ripidolite. 
 WINCHESTER and WILTON.—Asbestus, garnet. 
 
 NEW YORK. 
 
 ALBANY CO.—BEtTHLEHEM.—Calcite, stalactite, stalagmite, calca- 
 reous sinter, snowy gypsum. 
 
 CoEYMAN’s LANDING.--Gypsum, epsom salt, quartz crystals at 
 Crystal Hill, three miles south of Albany. 
 
 GUILDERLAND.—Petroleum, anthracite, and calcite, on the banks 
 of Norman’s Kill, two miles south of Albany. 
 
 WATERVLIET.—Quartz crystals, yellow drusy quartz. 
 
 ALLEGHANY CO.—Cusa.—Calcareous tufa, petroleum, 3} miles 
 from the village. 
 
 CATTARAUGUS CO.—FREEDOM.—Petroleum. 
 
 CAYUGA CO.—AuBURN.—Celestite, calcite, fluor spar, epsomite. 
 
 SPRINGPORT.—At Thompson’s plaster beds, sulphur! selenite. 
 
 SPRINGVILLE.— Nitrogen springs. 
 
 Union SpPRINGS.—Selenite, gypsum. 
 
 CHATAUQUE CO.—FreEponia.—Petroleum, carburetted hydrogen. 
 
 LAONA.—Petroleum. 
 
 CLINTON CO.—ARNOLD IRon MinE.— Magnetite, epidote, molybde- 
 nite. 
 
 Fincu OrE BED.—Calcite, green and purple fluor. 
 
 COLUMBIA CO.—AvsTERLITz. —- Harthy manganese, wulfenite, 
 chalcocite ; Livingston lead mine, galenite. 
 
 CHATHAM.—Quartz, pyrite in cubic crystals in slate (Hillsdale). 
 
 CANAAN.—Chalcocite, chalcopyrite. 
 
 Hupson.—Epidote, selenite / 
 
 New Lepanon.—Nitrogen springs, graphite, anthracite; at the 
 Ancram lead mine, galenite, barite, blende, wulfenite (rare), chalcopy- 
 rite, calcareous tufa; near the city of Hudson, epsom salt, brown 
 spar, wad. 
 
 DUTCHESS CO.—AMENIA.—Dolomite, limonite, turgite. 
 
 BEEKMAN.— Dolomite. 
 
 DoveR.—Dolomite, tremolite, garnet (Foss ore bed), staurolite, 
 limonite. 
 
 FIsHKILL.—Dolomite ; near Peckville, talc, asbestus, graphite, horn- 
 blende, augite, actinolite, hydrous anthophyllite, Zimonite. 
 
 Nortu East.—Chalcocite, chalcopyrite, galenite, blende. 
 
 RHINEBECK.—Calcite, green feldspar, epidote, tourmaline. 
 
 Union VALE.—At the Clove mine, gibbsite, limonite. 
 
 ESSEX GO.—ALEXANDRIA.—Kirby’s graphite mine, graphite, py- 
 roxene, scapolite, sphene. 
 
 Crown Pornt.—Apatite (eupyrchroite of Emmons), brown tourma- 
 line! in the apatite, chlorite, quartz crystals, pink and blue calcite, 
 
344 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. — 
 
 pyrite; a short distance south of J. C. Hammond’s house, garnet, 
 scapolite, chalcopyrite, aventurine feldspar, zircon, magnetic iron 
 (Peru), epidote, mica. 
 
 KEENE.—NScapolite. 
 
 Lewis.—Zabular spar, colophonite, garnet, labradorite, hornblende, 
 actinolite ; ten miles south of the village of Keeseville, arsenopyrite. 
 
 Lona Ponp.—Apatite, garnet, pyroxene, idocrase, coccolite !! scapo- 
 lite, magnetite, blue calcite. 
 
 McIntyrE.—Labradorite, garnet, magnetite. 
 
 Morrau, at Sandford Ore Bed.—Magnetite, apatite, ailanite/ lan- 
 thanite, actinolite, and feldspar; at Fisher Ore Bed, magnetite, feld- 
 spar, quartz; at Hail Ore Bed, or “‘ New Ore Bed,” magnetite, zircons ; 
 on Mill brook, calcite, pyroxene, hornblende, albite ; in the town of 
 Moriah, magnetite, black mica ; Barton Hill Ore Bed, albite. 
 
 Newcomsp.—Labradorite, feldspar, magnetite, hypersthene. 
 
 Port Henry.—Brown tourmaline, mica, rose quarte, serpentine, 
 green and black pyroxene, hornblende, cryst. pyrite, graphite, wollas- 
 tonite, pyrrhotite, adularia; phlogopite! at Cheever Ore Bed, with 
 magnetite and serpentine. 
 
 RocEr’s Rocx.—Graphite, wollastonite, garnet, collophonite, feld- 
 spar, adularia, pyroxene, sphene, coccolite. 
 
 Scoroon.—Calcite, pyroxene, chondrodite. 
 
 TICONDEROGA.—Graphite ! pyroxene, sahlite, sphene, black tour- 
 maline, cacoxene? (Mt. Defiance). 
 
 WEsTPORT.—Labradorite, prehnite, magnetite. 
 
 PA tas em iL oath colophonite, garnet, green coccolite, horn- 
 blende. 
 
 ERIE CO.—Eu.icort’s Mruis.—Calcareous tufas. 
 
 FRANKLIN CO.—CHaTEauGay. — Nitrogen springs, calcareous 
 tufas. 
 
 MALoNnE.— Massive pyrite, magnetite. 
 
 GENESEE CO.—Acid springs containing sulphuric acid. 
 
 GREENE CO.—CartTsxILu.——Calcite. 
 
 DIAMOND Hitu.—Quartz crystals. 
 
 HAMILTON CO.—Lone LAKE.—Blue calcite. 
 
 HERKIMER CO.—FatrFIeLD.—Quartz crystals, fetid barite. 
 
 LirtLE Fais.—Quarte crystals! barite, calcite, anthracite, pearl 
 spar, smoky quartz; one mile south of Little Falls, calcite, brown 
 spar, feldspar. 
 
 MIDDLEVILLE.—Quartz crystals! calcite, brown and pearl spar, an- 
 thracite. 
 
 NEewport.—Quartz crystals. 
 
 SALISBURY.—Quartz crystals! blende, galenite, pyrite, chalcopyrite. 
 
 STARK.—Fibrous celestite, gypsum. 
 
 JEFFERSON CO.—ApAms.—Fluor, calc tufa, barite. 
 
 ALEXANDRIA.—On the §. E. bank of Muscolonge Lake, fluorite 
 (exhausted), phlogopite, chalcopyrite, apatite ; on High Island, in the St. 
 Lawrence River, feldspar, tourmaline, hornblende, orthoclase, celestite. 
 
 ANTWERP.—Sterling iron mine, hematite, chalcodite, siderite, mil- 
 lerite, red hematite, crystallized quartz, yellow aragonite, niccoliferous 
 pyrite, guarte crystals, pyrite; at Oxbow, calcite! porous coralloidal 
 heavy spar; near Vrooman’s lake, calcite / vesuvianite, phlogopite ! 
 pyroxene, sphene, fluorite, pyrite, chalcopyrite ; also feldspar, bog-tron 
 
_ CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 345 
 
 ore, scapolite (farm of Eggleson), serpentine, tourmaline (yellow, 
 rare). 
 
 Seen: = Calectite in slender crystals, calcite (four miles 
 from Watertown). 
 
 NATURAL BRIDGE.—Gieseckite! steatite pseudomorphous after py- 
 roxene, apatite. 
 
 New ConnectTicut.—Sphene, brown phlogopite. 
 
 Omar.—Beryl, feldspar, hematite. 
 
 PHILADELPHIA.—Garnets on Indian River, in the village. 
 
 PAMELIA.—Agaric mineral, calc tufa. 
 
 PIERREPONT.—Tourmaline, sphene, scapolite, hornblende. 
 
 PILLAR Pornt.— Massive barite (exhausted), 
 
 THERESA.—Fluorite, calcite, hematite, hornblende, quartz crystal, 
 serpentine (associated with hematite), celestite, strontianite. 
 
 WATERTOWN.—Tremolite, agaric mineral, calc tufa, celestite. 
 
 Witna.—One mile north of Natural Bridge, calcite. 
 
 LEWIS CO.—D1ana (localities mostly near junction of crystalline 
 and sedimentary rocks, and within two miles of Natural Bridge).— 
 Scapolite/ wollastonite, green coccolite, feldspar, tremolite, pyroxene / 
 sphene! / mica, quartz crystals, drusy quartz, cryst. pyrite, pyrrhotite, 
 blue calcite, serpentine, rensselacrite, zircon, graphite, chlorite, hema- 
 tite, bog-iron ore, iron sand, apatite. 
 
 GREIG.—Magnetite, pyrite. 
 
 LOWVILLE.—Calcite, fluorite, pyrite, galenite, blende, calc tufa. 
 
 MARTINSBURGH.—Wad, galenite, etc., but mine not now opened, 
 calcite. 
 
 MONROE CO.—RocHEsTER.—Pearl spar, calcite, snowy gypsum, 
 fluor, celestite, galenite, blende, barite, hornstone. 
 
 MONTGOMERY CO.—PaALatTIne.—Quartz crystals, drusy quartz, 
 anthracite, hornstone, agate, garnet. 
 
 Root.—Drusy quartz, blende, barite, stalactite, stalagmite, galenite, 
 pyrite. 
 
 NEW YORK CO.—CoRLEAR’s Hoox.—Apatite, brown and yellow 
 feldspar, sphene. 
 
 HARLEM.—HEpidote, apophyllite, stilbite, tourmaline, vivianite, 
 lamellar feldspar, mica. 
 
 KINGSBRIDGE.— Tremolite, pyroxene, mica, tourmaline, pyrite, rutile, 
 dolomite. 
 
 New Yorx.—Serpentine, amianthus, actinolite, pyroxene, hydrous 
 anthophyllite, garnet, staurolite, molybdenite, graphite, chlorite, 
 jasper, necronite, feldspar. In the excavations for the 4th Avenue 
 tunnel, 1875, harmotome, stilbite, chabazite, heulandite, etc. 
 
 NIAGARA CO.—LEwIston.—Epsomite. 
 
 - LocKxPort.—Celestite, calcite, selenite, ‘anhydrite, fluorite, dolomite, 
 ende. 
 
 NIAGARA FALLS.—Calcite, fluorite, blende, dolomite. 
 
 ONEIDA CO.—BOONVILLE.—Calcite, wollastonite, coccolite. 
 
 CLINTON.——blende, lenticular argillaceous iron ore in rocks of the 
 Clinton group, strontianite, celestite, the former covering the latter. 
 
 ONONDAGA CO.—CamiILuvus.—Selenite and fibrous gypsum. 
 
 CoLD SPRING.—Axinite. 
 
 MANLIvUs.—Gypsum and fluor. 
 
 SYRACUSE. — Serpentine, celestite, selenite, barite. 
 
346 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. — 
 
 ORANGE CO.—CorNWALL.—Zircon, chondrodite, hornblende, spinel, 
 massive feldspar, fibrous epidote, hudsonite, menaccanite, serpentine, 
 coccolite. 
 
 DEER Parx.—Cryst. pyrite, galenite. 
 
 Monroz.—WMica/ sphene! garnet, colophonite, epidote, chondrodite, 
 allanite, bucholzite, brown spar, spinel, hornblende, talc, menaccanite, 
 pyrrhotite, pyrite, chromite, graphite, rastolyte, moronolite. 
 
 At Wriuks and O’Neruu Mine in Monroe.—Aragonite, magnetite, 
 dimagnetite (pseud.*), jenkinsite, asbestus, serpentine, mica, hortono- 
 lite. 
 
 At Two Ponps in Monroe.—Pyrowene ! chondrodite, hornblende, 
 scapolite! zircon, sphene, apatite. 
 
 At GREENWOOD FuRNACE in Monroe.—Chondrodite, pyrowene ! 
 mica, hornblende, spinel, scapolite, biotite / menaccanite. 
 
 At FoREST OF DEAN.—Pyrowene, spinel, zircon, scapolite,. horn- 
 blende. 
 
 TowN OF WARWICK, WARWICK VILLAGE.—Spinel / zircon, serpen- 
 tine! brown spar, pyroxene ! hornblende! pseudomorphous steatite, 
 feldspar! (Rock Hill), menaccanite, clintonite, tourmaline (R. H.), 
 putile, sphene, molybdenite, arsenopyrite, marcasite, pyrite, yellow 
 iron sinter, quartz, jasper, mica, coccolite. 
 
 Amity.—ASpinel! garnet, scapolite, hornblende, vesuvianite, epidote ! 
 clintonite! magnetite, tourmaline, warwickite, apatite, chondrodite, 
 tale! pyrovene! rutile, menaccanite, zircon, corundum, feldspar, 
 sphene, calcite, serpentine, schiller spar (?), silvery mica. 
 
 EDENVILLE.— Apatite, chondrodite! hair-brown hornblende / tremo- 
 lite, spinel, tourmaline, warwickite, pyrovene, sphene, mica, feldspar, 
 arsenopyrite, orpiment, rutile, menaccanite, scorodite, chalcopyrite, 
 leucopyrite (or léllingite), allanite. 
 
 West Point.—Feldspar, mica, seapolite, sphene, hornblende, allanite. 
 
 PUTNAM CO.—BrewsTER, Tilly Foster Iron Mine. —Chondrodite ! 
 (also humite and clino-humite) crystals very rare, magnetite, dolomite, 
 serpentine, pseudomorphs, brucite, enstatite, ripidolite, biotite, actino- 
 lite, avatite, pyrrhotite, fluorite, albite, epidote, sphene. 
 
 Antuony’s Noss, at top, pyrite, pyrrhotite, pyroxene, hornblende, 
 magnetite. 
 
 CARMEL (Brown’s quarry).—Anthophyllite, schiller spar (2), orpi- 
 ment, arsenopyrite, epidote. 
 
 CoLp SPRING.—Chabazite, mica, sphene, epidote. 
 
 Parrarson.— White pyrowene! calcite, asbestus, tremolite, dolomite, 
 massive pyrite. 
 
 PHrtiiestown.—Tremolite, amianthus, serpentine, sphene, diopside, 
 green coccolite, hornblende, scapolite, stilbite, mica, laumontite, gur- 
 hofite, calcite, magnetite, chromite. 
 
 Puitiips Ore Bed.—Hyalite, actinolite, massive pyrite. 
 
 RENSSELAER CO.—Hoostc.—Nitrogen springs. 
 
 LANSINGBURGH.—Epsomite, quartz crystals, pyrite. 
 
 Troy.—Quartz crystals, pyrite, selenite. aS 
 
 RICHMOND CO.—RossviLLE.—Lignite, eryst. pyrite. 
 
 QUARANTINE.—Asbestus, amianthus, aragonite, dolomite, gurhofite, 
 brucite, serpentine, talc, magnesite. 
 
 ROCKLAND CO.—CALDWELL.— Calcite. 
 
 Grassy Pornt.—Serpentine, actinolite. 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. B47 
 
 HAVERSTRAW.—Hornblende, barite. 
 
 LADENTOWN.—Zircon, malachite, cuprite. 
 
 PIERMONT.—Datolite, stilbite, apophyllite, stellite, prehnite, thom- 
 sonite, calcite, chabazite. 
 
 ST. LAWRENCE CO.—Canton.—WMassive pyrite, calcite, brown 
 tourmaline, sphene, serpentine, talc, rensselaerite, pyroxene, hematite, 
 chalcopyrite. 
 
 DE Kas.—Hornblende, barite, fluorite, tremolite, tourmaline, blende, 
 graphite, pyroxene, quartz (spongy), serpentine. 
 
 EDWARDS,— brown and silvery mica! scapolite, apatite, guarte crys- 
 tals, actinolite, tremolite! hematite, serpentine, magnetite. 
 
 Fine.—Black mica, hornblende. 
 
 Fow.EeR.—Barite, quartz crystals! hematite, blende, galenite, tremo- 
 lite, chalcedony, bog ore, satin spar (assoc. with serpentine), pyrite, 
 chalcopyrite, actinolite, rensselaerite (near Somerville). 
 
 GOUVERNEUR.—Caicite! serpentine! hornblende! scapolite! ortho- 
 clase, tourmaline / idocrase (one mile south of G.), pyroxene, malaco- 
 lite, apatite, rensselaerite, serpentine, sphene, fluorite, barite (farm of 
 Judge Dodge), black mica, phlogopite, tremolite/ asbestus, hematite, 
 graphite, vesuvianite (near Somerville in serpentine), spinel, houghite,. 
 scapolite, phlogopite, dolomite ; three-quarters of a mile west of Som- 
 erville, chondrodite, spinel ; two miles north of Somerville, apatite, 
 pyrite, brown tourmaline ! ! 
 
 HAMMOND.— Apatite! zircon! (farm of Mr. Hardy), orthoclase (loxo- 
 case), pargasite, barite, pyrite, purple fluorite, dolomite. 
 
 HEeRMon.—Quarte crystals, hematite, siderite, pargasite, pyroxene, 
 serpentine, tourmaline, bog-iron ore. 
 
 MacomBs.—Blende, mica, galenite (on land of James Averill), 
 sphene. 
 
 MINERAL Point, Morristown.—Fluorite, blende, galenite, phlogo- 
 \pite (Pope’s Mills), barite. 
 
 OGDENSBURGH.—Labradorite. 
 
 PITCAIRN.—Satin spar, associated with serpentine. 
 
 PotspAM.—Hornblende! ; eight miles from Potsdam, on road to 
 Pierrepont, feldspar, tourmaline, black mica, hornblende. 
 
 Rossiz (Iron Mines).—Barite, hematite, coralloidal aragonite in 
 mines near Somerville, limonite, quartg (sometimes stalactitic at 
 Parish Iron Mine), pyrite, pearl spar. 
 
 Rossrz Lead Mine.—Calcite! galenite! pyrite, celestite, chalcopyrite, 
 hematite, cerussite, anglesite, octahedral fluor, black phlogopite. 
 
 Elsewhere in Rossix.—Calcite, barite, quartz crystals, chondrodite 
 (near Yellow Lake), feldspar! pargasite! apatite, pyroxenc, horn- 
 blende, sphene, zircon, mica, fluorite, serpentine, automolite, pearl 
 spar, graphite. 
 
 RUssEL.—Pargasite, specular tron, quartz (dodec.), calcite, serpen- 
 tine, rensselaerite, magnetite. 
 
 SARATOGA CO.—GREENFIELD.—Chrysoberyl! garnet! tourma- 
 line! mica, feldspar, apatite, graphite, aragonite (in iron mines). 
 
 SCHOHARIE CO.—Bat1’s CAVE, and others.—Calcite, stalactites. 
 
 CARLISLE.—/ibrous barite, cryst. and fibrous calcite. 
 
 MIDDLEBURY.—Asphaltic coal, calcite. 
 
 SHARON.—Calcareous tufa. 
 
 ScHOHARIE.—Fibrous celestite, strontianite ! cryst. pyrite! 
 
8348 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 SENECA CO.—Canoca.—Witrogen springs. 
 
 SULLIVAN CO.—WuRrtTzBoR0’.—Galenite, blende, pyrite, chalco- 
 
 rite. 
 
 TOMPKINS CO.—ITHaca. —Calcareous tufa. 
 
 ULSTER CO, — ELLENVILLE. — Galenite, blende, chalcopyrite ! 
 quartz, brookite. 
 
 MARBLETOWN.—Pyrite. 
 
 WARREN CO.—CALDWELL.— Massive feldspar. 
 
 CuEstTeR.—Pyrite, tourmaline, rutile, chalcopyrite. 
 
 DIAMOND IsLE (Lake George).—Calcite, quarta crystals. 
 
 GLENN’sS FaLus.—Rhomb spar. 
 
 JounsBurcH.—Fluorite! zircon! graphite, serpentine, pyrite. 
 
 WASHINGTON CO.—Fort ANN.— Graphite, serpentine. 
 
 GRANVILLE.—Lamellar pyrovene, massive feldspar, epidote. 
 
 WAYNE CO.—WotcortT.—Barite. 
 
 WESTCHESTER CO.—AnTHoNyY’s Nosn.— Apatite, pyrite, calcite! 
 in very large tabular crystals, grouped, and sometimes incrusted. with 
 drusy quartz. 
 
 DAVENPORT’s Necx.—Serpentine, garnet, sphene. 
 
 ' EASTCHESTER.—Blende, pyrite, chalcopyrite, dolomite. 
 
 Hastines.—Tremolite, white pyroxene. 
 
 New RocuHEeie.—Serpentine, brucite, quartz, mica, tremolite, gar- 
 net, magnesite. 
 
 PEEKSKILL.—Mica, feldspar, hornblende, stilbite, sphene; three 
 miles south, emery. 
 
 Ryn.—Serpentine, chlorite, black tourmaline, tremolite. 
 
 Sing Sinc.—Pyroxene, tremolite, pyrite, beryl, azurite, green mala- 
 chite, cerussite, pyromorphite, ang lesite, vauquelinite, galenite, native — 
 silver, chalcopyrite. 
 
 West Farms.—Apatite, tremolite, garnet, stilbite, heulandite, cha- 
 bazite, epidote, sphene. 
 
 YonxeEns.—Tremolite, apatite, calcite, analcite, pyrite, tcurmaline. 
 YorkKTOWN.—Tibrolite, monazite, magnetite. 
 WYOMING CO.—Wyomine.—Rock salt. 
 
 NEW JERSEY. 
 
 ANDOVER IRON MINE (Sussex Co.)—Willemite, brown garnet. 
 ALLENTOWN (Monmouth Co. )— Vivianite, dufrenite. 
 BELLVILLE.—Copper mines. 
 
 BERGEN.—Calcite! datolite! pectolite! analeite, apophyllite ! gme- 
 linite, prehnite, sphene, stilbite, natrolite, heulandite, laumontite, cha- 
 bazite, pyrite, pseudomorphous steatite imitative of apophyllite, 
 diabantite. 
 
 PBRUNSWICK.—Copper mines: native copper, malachite, mountain 
 leather. 
 
 BryamM.—Chondrodite, spinel, at Roseville, epidote. 
 
 CANTWELL’S BRIDGE (Newcastle Co.), three miles west.—Vivian- 
 ite. 
 
 DANVILLE (Jemmy Jump Ridge).—G@raphite, chondrodite, augite, 
 mica. 
 
 FLEMINGTON.—OCopper munes. 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 849 
 
 FRANKFORT. —Serpentine. 
 
 FRANKLIN and STERLING (Sussex Co.)—Spinel/ garnet! rhodonite ! 
 willemite ! franklinite ! zincite ! dysluite! hornblende, tremolite, chondro- 
 dite, white scapolite, black tourmaline, epidote, mica, actinolite, augite, 
 sahlite, coccolite, asbestus, jeffersonite (augite), calamine, graphite, 
 fluorite, beryl, galenite, serpentine, honey-colored sphene, quartz, 
 chalcedony, amethyst, zircon, molybdenite, vivianite, tephroite, rhodo- 
 chrosite, aragonite, sussexite, chalcophanite, roepperite, calcozincite, 
 vanuxemite, gahnite, hetzrolite. Also algerite in gran. limestone. 
 
 FRANKLIN and Warwick Mts.—Pyrite. 
 
 GREENBROOK.—Copper mines. 
 
 GRIGGSTOWN.—Copper mines. 
 
 HamMBuRGH.—One mile north, spinel / tourmaline, phlogopite, horn- 
 blende, limonite, hematite. 
 
 HoBoxKENn.—Serpentine (marmolite), brucite, nemalite (or fibrous bru- 
 cite), aragonite, dolomite. 
 
 HuRDsTOWN.—Apatite, pyrrhotite, magnetite. 
 
 IMLAYSTOWN.—-Vivianite. 
 
 Lockwoop.—Graplite, chondrodite, tale, augite, quartz, green spi- 
 nel. 
 
 MONTVILLE (Morris Co.)—Serpentine, chrysotile. 
 
 Mouuica Hix (Gloucester Co.)—Vivianite lining belemnites and 
 other fossils. 
 
 NrwrTon.—Spinel, blue, pink, and white corundum, mica, vesuvian- 
 ite, hornblende, tourmaline, scapolite, rutile, pyrite, talc, calcite, barite, 
 pscudomorphous steatite. 
 
 PATERSON.— Datolite. 
 
 VERNON.—Serpentine, spinel, hydrotalcite. 
 
 PENNSYLVANIA.* 
 
 ADAMS CO.—GurrysBurc.—Epidote, fibrous and massive. 
 
 BERKS Co.—MorcGantown.—At Jones’s mines, one mile east of 
 Morgantown, malachite, native copper, chrysocolla, magnetite, allo- 
 phane, pyrite, chalcopyrite, aragonite, apatite, talc, venerite ; two 
 miles N. EK. from Jones’s mine, graphite, sphene; at Steele’s mine, 
 one mile N. W. from St. Mary’s, Chester Co., magnetite, micaceous 
 iron, coccolite, brown garnet. 
 
 READING.--Smoky quartz crystals, zircon, stilbite, iron ore ; near 
 Pricetown, zircon, allanite, epidote; at Eckhardt’s Furnace, allanite 
 with zircon ; at Zion’s Chureh, molybdenite ; near Kutztown, in the 
 Crystal Cave, stalactites ; at Fritz Island, apophyllite, thomsonite, cha- 
 bazite, calcite, azurite, malachite, magnetite, chalcopyrite, stibnite, 
 prochlorite, precious serpentine. 
 
 BUCKS CO.—BuckineHam TownsuHip.—Crystallized quartz ; near 
 New Hope, vesuvianite, epidote, barite. 
 
 SOUTHAMPTON.—Near the village of Feasterville, in the quarry of 
 George Van Arsdale, graphite, pyroxene, sahlite, coccolite, sphene, 
 green mica, calcite, wollastonite, glassy feldspar sometimes opalescent, 
 phlogopite, blue quartz, garnet, zircon, pyrite, moroxite, scapolite, 
 
 
 
 fe See also the Report on the Mineralogy of Pennsylvania, by Dr. A. F. Genth, 
 By 
 
350 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 Nrw Britarn.—Dolomite, galenite, blende, malachite. 
 
 CHESTER CO.—AVONDALE.—Asbestus, tremolite, garnet, opal. 
 
 CARBON CO.--Summit Hi11, in coal mines.—Kaolimte. 
 
 BrrmMincuam Townsurp. — Amethyst, smoky quartz, serpentine, 
 beryl; in Ab’m Darlington’s lime quarry, calcite. 
 
 East BRapFrorD.—Near Buffington’s bridge, on the Brandywine, 
 green, blue, and gray cyanite, the gray cyanite found loose in the 
 soil, in crystals ; on the farms of Dr. Elwyn, Mrs. Foulke, Wm. Gib- 
 bons, and Saml. Entrikin, amethyst. At Strode’s mill, asbestus, mag- 
 nesite, anthophyllite, epidote, aquacrepitite, oligoclase, drusy quartz, 
 collyrite ? on Osborne’s Hill, wad, manganesian garnet (massive), sphene 
 schorl ; at Caleb Cope’s lime quarry, fetid dolomite, necronite, garnets, 
 blue cyanite, yellow actinolite in talc ; near the Black Horse Inn, indu- 
 rated talc, rutile ; on Amos Davis’s farm, orthite / massive, froma grain 
 to lumps of one pound weight ; near the paper-mill on the Brandy- 
 wine, zircon, associated with titaniferous dron in blue quartz. 
 
 Wurst BRADFORD.—Near the village of Marshalton, green cyanite, 
 rutile, scapolite, pyrite, gtaurolite ; at the Chester County Poor-house 
 limestone quarry, chesterlite / in crystals implanted on dolomite, 72- 
 jile | in brilliant acicular crystals, which are finely terminated, calcite 
 in scalenohedrons, zoisite, damourite ? in radiated groups of crystals 
 on dolomite, guartz crystals ; on Smith & McMullin’s farm, epidote 
 
 CHARLESTOWN.—Pyromorphite, cerussite, galenite, quartz. 
 
 CoveNnTRY.—Allanite, near Pughtown. 
 
 Soutu CoveNTRY.—In Chrisman’s limestone quarry, near Coventry 
 village, augite, sphene, graphite, zircon in iron ore (about half a mile 
 from the village). 
 
 East FALLOWFIELD.—Soapstone. 
 
 East GosHEN.-—Serpentine, asbestus, magnetite (lodestone), gar- 
 net. 
 
 E.K.—-Menaccanite with muscovite, chromite ; at Lewisville, black 
 tourmaline. 
 
 Wrst GosHEN.—On the Barrens, one mile north of West Chester, 
 amianthus, serpentine, cellular quartz, jasper, chalcedony, drusy 
 quartz, chlorite, marmolite, indurated tale, magnesite in radiated crys- 
 tals on serpentine, hematite, asbestus; near R. Taylor’s mill, chromite 
 in octahedral crystals, deweylite, radiated magnesite, aragonite, stauro- 
 lite, garnet, asbestus, epidote ; zoisite on hornblende at West Chester 
 water-works (not accessible at present). 
 
 New GARDEN.—At Nivin’s limestone quarry, brown tourmaline, ne- 
 cronite, scapolite, apatite, brown and green mica, rutile, aragonite, 
 fibroliie, kaolinite, tremolite. 
 
 KENNETT.—Actinolite, brown tourmaline, brown mica, epidote, tre- 
 molite, scapolite, aragonite ; on Wm. Cloud's farm, sunstone/ / cha- 
 bazite, sphene. At Pearce’s old mill, zoisite, epidote, sunstone ; sun- 
 stone occurs in good specimens at various places in the range of horn- 
 blende rocks running through this township from N. E. to8. W. 
 
 LOWER Oxrorp.—Garnets, pyrite in cubic crystals. . . 
 
 LONDON GRovE.—Rutile, jasper, chalcedony (botryoidal), large and 
 rough quartz crystals, epidote ; on Wm. Jackson’s farm, yellow and 
 black tourmaline, tremolite, rutile, green mica, apatite ; at Pusey’s 
 quarry, rutile, ¢remolite. 
 
 East MarL~BoroucH.—On the farm of Bailey & Brother, one mile 
 
 1 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 851 
 
 south of Unionville, bright yellow and nearly white towrmaline, ches- 
 terlite, albite, pyrite ; near Marlborough meeting-house, epidote, ser- 
 pentine, acicular black tourmaline in white quartz; zircon in small 
 perfect crystals loose in the soil at Pusey’s sawmill, two miles S. W. 
 of Unionville. 
 
 West MARLBOROUGH.—Near Logan’s quarry, staurolite, cyanite, 
 yellow tourmaline, rutile, garnets ; near Doe Run village, hematite, 
 scapolite, tremolite ; in R. Baily’s limestone quarry, two and a half 
 miles 8. W. of Unionville, fibrous tremolite, cyanite, scapolite. 
 
 NEWLIN.—On the serpentine barrens, one and a half mile N. E. of 
 Unionville, corundum / massive and crystallized, also in crystals in 
 albite, often in loose crystals covered with a thin coating of steatite, 
 spinel (black), talc, picrolite, brucite, green tourmaline with flat pyram- 
 idal terminations in albite, wnionite (rare), euphyllite, micain hexagonal 
 crystals, feldspar, beryl / in hexagonal crystals one of which weighs 
 51 lbs., pyrite in cubic crystals, chromic iron, drusy quartz, green 
 quartz, actinolite, emerylite, chloritoid, diallage, oligoclase ; on John- 
 son Patterson’s farm, massive corundum, titaniferous iron, clinochlore, 
 emerylite, sometimes colored green by chrome, albite, orthoclase, hal- 
 loysite, margarite, garnets, beryl; on J. Lesley’s farm, corundum, 
 crystallized and in massive lumps one of which weighed 5,200 Ibs., 
 diaspore !! emerylite! euphyllite crystailized! green tourmaline, in 
 transparent crystals in the euphyllite, orthoclase ; two miles N. of 
 Unionville, magnetite in octahedral crystals; one mile HE. of Union- 
 ville, hematite ; in Edwards’s old limestone quarry, purple fluorite, 
 rutile. 
 
 East NotrineHam.—A sbestus, chromite in crystals, hallite, beryl. 
 
 West NorrincHam.—At Scott’s chrome mine, chromite, foliated 
 tale, marmolite, serpentine, chalcedony, rhodochrome ; near Moro Phil- 
 lips’s chrome mine, asbestus ; at the magnesia quarry, deweylite, mar- 
 molite, magnesite, leelite, serpentine, chromite ; near Fremont P. O., 
 corundum. 
 
 WEsT PIKELAND.—In the iron mines near Chester Springs, gibbsite, 
 zircon, turgite, hematite (stalactitical and in geodes), géthite. 
 
 PENN.—Garnets, agalmaitolite. 
 
 PENNSBURY.—On John Craig’s farm, brown garnets, mica; on J. 
 Dilworth’s farm, near Fairville, muscovite! in the village of Fair- 
 ville, swnstone ; near Brinton’s Ford, on the Brandywine, chondrodite, 
 sphene, diopside, augite, coccolite; at Mendenhall’s old limestone 
 quarry, fetid quartz, sunstone ; at Swain’s quarry, orthoclase. 
 
 Pocorpson.—On the farms of John Entrikin and Jos. B. Darlington, 
 amethyst. 
 
 SapsBurY.—Rutile / / splendid geniculated crystals are found loose 
 in the soil for seven miles along the valley, and particularly near the 
 village of Parkesburg, where they sometimes occur weighing one 
 pound, doubly geniculated and of a deep red color; near Sadsbury 
 village, amethyst, tourmaline, epidote, milk quarte. 
 
 ScHUYLKILL.—In the railroad tunnel at PHasnrxviiue, dolomite / 
 sometimes coated with pyrite, quartz crystals, yellow blende, brookite, 
 calcite in hexagonal crystals enclosing pyrite; at the WHEATLEY, 
 BROOKDALE, and CHESTER CouNTY LEAD MINgs, one and a half 
 mile 8. of Phoenixville, pyromorphite ! cerussite! galenite, anglesite ! / 
 quartz crystals, chalcopyrite, barite, fluorite (white), stolzite, wulfenite / 
 
352 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 calamine, vanadinite, blende ! mimetite! descloizite, githite, chryso- 
 colla, native copper, malachite, azurite, limonite, calcite, sulphur, py- 
 rite, melaconite, pseudomalachite, gersdorfiite, chalcocite? covellite. 
 
 THORNBURY.—On Jos. H. Brinton’s farm, muscovite containing acic- 
 ular crystals of tourmaline, rutile, titaniferous iron. 
 
 TREDYFFRIN.—Pyrite in cubic crystals loose in the soil. 
 
 UwcHian.—Massive blue quartz, graphite. 
 
 WaRREN.— Melanite, feldspar. 
 
 West GOSHEN (one mile from West Chester).—Chromite. 
 
 WILLIstowNn.—Magnetite, chromite, actinolite, asbestus. 
 
 Wrst Town.—On the serpentine rocks, 3 miles 8. of West Ches- 
 ter, clinochlore ! jefferisite / mica, asbestus, actinolite, magnesite, tale, 
 titaniferous iron, magnetite and massive tourmaline. 
 
 East WuHItTELAND.—Pyrite, in cubic crystals, quartz crystals. 
 
 Wurst WHITELAND.—At Gen. Trimble’s iron mine (southeast), stal- 
 actitic hematite! wavellite/ / in radiated stalactites, gibbsite, coeruleo- 
 lactile. 
 
 Warwitok.—At the Elizabeth mine and Keim’s old iron mine 
 adjoining, one mile N. of Knauertown, aplome garnet! in brilliant 
 dodecahedrons, flosferri, pyroxene, micaceous hematite, pyrite in bright 
 octahedral crystals in calcite, chrysocolla, chalcopyrite massive and in 
 single tetrahedral crystals, magnetite, fascicular hornblende ! bornite, 
 malachite, brown garnet, calcite, byssolite / serpentine ; near the village 
 of St. Mary’s, magnetite in dodecahedral crystals, melanite, garnet, 
 actinolite in small radiated nodules ; at the Hopewell iron mine, one 
 mile N. W. of St. Mary’s, magnetite in octahedral crystals. 
 
 COLUMBIA CO.—At Webb's mine, yellow blende in calcite ; near 
 Bloomburg, cryst. magnetite. 
 
 DAUPHIN CO.—NEAR HluMMERSTOWN.—Green garnets, cryst. 
 smoky quartz, feldspar. 
 
 DELAWARE CO.—ASTON Townsute.—Amethyst, corundum, eme- 
 rylite, staurolite, fibrolite, black tourmaline, margarite, sunstone, asbes- 
 tus, anthophyllite, steatite ; near Tyson’s mill, garnet, staurolite ; at 
 Peter’s milldam in the creek, pyropé garnet. 
 
 BIRMINGHAM.—Tibrolite, kaolin (abundant), crystals of rutile, ame- 
 thyst ; at Bullock’s old quarry, zircon, bucholzite, nacrite, yellow crys- 
 tallized quartz, feldspar. 
 
 BLUE Hitu.—Green quartz crystals, spinel. 
 
 CuEstEeR.—Amethyst, black tourmaline, beryl, crystals of feldspar, 
 garnet, cryst. pyrite, molybdenite, molybdite, chalcopyrite, kaolin, ura- 
 ninite, muscovite, orthoclase, bismutite. 
 
 CHicHESTER.—Near Trainer’s milldam, beryl, tourmaline, crystals 
 of feldspar, kaolin ; on Wm. Eyre’s farm, toyrmaline. 
 
 ConcorD.—WMica, feldspar, kaolin, drusy quarte, meerschaum, stel- 
 lated tremolite, anthophyllite, fibrolite, acicular crystals of rutile, py- 
 rope in quartz, amethyst, actinolite, manganesian garnet, beryl; in 
 Green’s creek, pyrope garnet. 
 
 DarBy.—Blue and gray cyanite, garnet, staurolite, zoisite, quartz, 
 beryl, chlorite, mica, limonite. 
 
 EpaEmont.—Amethyst, oxide of manganese, crystals of feldspar; 
 one mile east of Edgemont Hall, rutile in quartz. 
 
 GREEN’s CREEK.—Garnet (so-called pyrope). 
 
 HAVERFoRD.—Staurolite with garnet. 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 353 
 
 MARPLE.—Tourmaline, andalusite, amethyst, actinolite, anthophyl- 
 lite, tale, radiated actinolite in tale, chromite, drusy quartz, beryl, 
 cryst. pyrite, menaccanite in quartz, chlorite. 
 
 MIDDLETOWN.— Amethyst, beryl, black mica, mica with reticulated 
 magnetite between the plates, manganesian garnets! large trapezo- 
 hedral crystals, some 8 in. in diameter, indurated talc, hexagonal 
 crystals of rutile, crystals of mica, green quartz! anthophyllite, radi- 
 ated tourmaline, staurolite, titanic iron, fibrolite, serpentine ; at Len- 
 ni, chlorite, green and bronze vermiculite! green feldspar ; at Mineral 
 Hill, fine crystals of corundum, one of which weighs 13 lb., actinolite 
 in great variety, bronzite, green feldspar, moonstone, sunstone, graphic 
 granite, magnesite, octahedral crystals of chromite in great quantity, 
 beryl, chalcedony, asbestus, fibrous hornblende, rutile, staurolite, me- 
 lanosiderite, hallite ; at Painter’s Farm, near Dismal Run, zircon with 
 oligoclase, tremolite, tourmaline; at the Black Horse, near Media, 
 corundum ; at Hibbard’s Farm and at Fairlamb’s Hill, chromite in 
 brilliant octahedrons. 
 
 NEwtTown.—Serpentine, hematite, enstatite, tremolite. 
 
 UPPER PROVIDENCE.—Anthophyllite, tremolite, radiated asbestus, 
 radiated actinolite, tourmaline, beryl, green feldspar, amethyst (one 
 found on Morgan Hunter’s farm weighing over 7 lbs.), andalusite / 
 (one terminated crystal found on the farm of Jas. Worrell weighs 74 
 lbs.) ; at Blue Hill, very fine crystals of blwe quartz in chlorite, amian- 
 thus in serpentine, zircon. 
 
 LOWER PROVIDENCE.— Amethyst, green mica, garnet, large crystals 
 of feldspar / (some over 100 lbs. in weight). 
 
 RaDNoR.—Garnet, marmolite, deweylite, chromite, asbestus, mag- 
 nesite, talc, blue quartz, picrolite, limonite, magnetite. 
 
 SPRINGFIELD.—Andalusite, tourmaline, beryl, titanic iron, garnet ; 
 on Fell’s Laurel Hill, beryl, garnet; near Beattie’s mill, staurolite, 
 apatite ; near Lewis’s paper-mill, tourmaline, mica. 
 
 THORNBURY.— Amethyst. 
 
 HUNTINGDON CO.—N#8AR FRANKSTOWN.—In the bed of a stream 
 and on the side of a hill, fibrous celestite (abundant), quartz crystals. 
 
 LANCASTER CO.—DrumoreE TownsHiIP.—Quartz crystals. 
 
 FuLton.—At Wood’s chrome mine, near the village of Texas, bru- 
 cite!/ zaratite (emerald nickel), pennite! ripidolite! kdmmererite! 
 baltimorite, chromite, williamsite, chrysolite/ marmolite, picrolite, 
 hydromagnesite, dolomite, magnesite, aragonite, calcite, serpentine, 
 hematite, menaccanite, genthite, chrome-garnet, bronzite, millerite ; 
 at Low’s mine, hydromagnesite, brucite (lancasterite), picrolite, magne- 
 site, williamsite, chromic iron, talc, zaratite, baliimorite, serpentine, 
 hematite ; on M. Boice’s farm, one mile N. W. of the village, pyrite in 
 cubes and various modifications, anthophyllite; near Rock Springs, 
 chalcedony, carnelian, moss agate, green tourmaline in talc, titanic iron, 
 chromite, octahedral magnetite in chlorite; at Reynolds’s old mine, 
 calcite, talc, picrolite, chromite ; at Carter’s chrome mine, brookite. 
 
 GAP MINEs.—Chalcopyrite, pyrrhotite (niccoliferous), millerite in 
 botryoidal radiations, vivianite/ (rare), actinolite, siderite, hisingerite, 
 pyrite. 
 
 PEQUA VALLEY.—Eight miles south of Lancaster, argentiferous 
 galenite (said to contain 250 to 300 ounces of silver to the ton?), vau- 
 quelinite, rutile at Pequea mine; four miles N, W, of Lancaster, on 
 
 23 
 
354. SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 the Lancaster and Harrisburg Railroad, calamite, galenite, blende ; 
 pyrite in cubic crystals is found in great abundance near the city of 
 Lancaster ; at the Lancaster zinc mines, calamine, blende, tennantite ? 
 smithsonite (pseud. of dolomite), aurichalcite. 
 
 LEBANON CO. —CorNWALL. — Magnetite; pyrite (cobaltiferous), 
 chalcopyrite, native copper, azurite, malachite, chrysocolla, euprite (hy- 
 drocuprite), allophane, brochantite, serpentine, quartz pseudomorphs ; 
 galenite (with octahedral cleavage), fluorite, covellite, hematite (mica- 
 ceous), opal, asbestus. . 
 
 LEHIGH CO.—FRIEDENSVILLE.—At the zinc mines, calamine, 
 smithsonite, hydrozincite, massive blende, greenockite, quartz, allo- 
 phane, zinciferous clay, mountain leather, aragonite, sauconite ; near 
 Allentown, magnetite, pipe-iron ore ; near Bethlehem, on 8. Mountain, 
 allanite, with zircon and altered sphene in a single isolated mass of 
 syenite, magnetite, martite, black spinel, tourmaline, chalcocite. 
 
 MIFFLIN CO.—Strontianite. 
 
 MONROE CO.—In CHERRY VALLEY. —Calcite, chalcedony, quartz ; 
 in Poconac Valley, near Judge Mervine’s, cryst. quartz. 
 
 MONTGOMERY CO.—CoNsHOHOCKEN. —Fibrous tourmaline, me- 
 naccanite, aventurine quartz, phyllite ; in the quarry of Geo. Bullock, 
 calcite in hexagonal prisms, aragonite. 
 
 LOWER PROVIDENCE.—At the Perkiomen lead and copper mines, 
 near the village of Shannonville, azurite, blende, galenite, pyromor- 
 phite, cerussite, wulfenite, anglesite, barite, calamine, chalcopyrite, 
 malachite, chrysocolla, brown spar, cuprite, covellite (rare), melaco- 
 nite. libethenite, pseudomalachite. 
 
 Wuitr Marsu.—At D. O. Hitner’s iron mine, five and a half miles | 
 from Spring Mills, limonite in geodes and stalactites, gothite, pyro- 
 lusite, wad, lepidocrocite ; at Edge Hill Street, North Pennsylvania 
 Railroad, titanic iron, braunite, pyrolusite ; one mile S. W. of Hitner’s 
 iron mine, limonite, velvety, stalactitic, and fibrous, fibres three inches 
 long, turgite, géthite, pyrolusite, veluet manganese, wad ; near Marble 
 Hall, at Hitner’s marble quarry, white marble, granular barite, resem- 
 bling marble ; at Spring Mills, limonite, pyrolusite, géthite; at Flat 
 Rock Tunnel, opposite Manayunk, stilbite, heulandite, chabasite, ilvaite, 
 beryl, feldspar, mica. 
 
 LAFAYETTE, at the Soapstone quarries.—Tale, jefferisite, garnet, 
 albite, serpentine, zoisite, staurolite, chalcopyrite ; at Rose’s Serpen- 
 tine quarry, opposite Lafayette, enstatite, serpentine. 
 
 NORTHAMPTON CO.—BvusHKILL TownsuIP.—Crystal Spring on 
 Blue Mountain, quartz crystals. 
 
 Near Easton.—Zircon/ (exhausted), nephrite, coccolite, tremolite, 
 pyroxene, sahlite, limonite, magnetite, purple calcite. 
 
 WitiaMs Townsure.—Pyrolusite in geodes in limonite beds, 
 goéthite (lepidocrocite) at Glendon. 
 
 NORTHUMBERLAND CO.— Opposite SELIN’S GROVE. — Cala- 
 mine. 
 
 PHILADELPHIA CO,—FRANKFORD.—Titanite in gneiss, apophyl- 
 lite ; on the Philadelphia, Trenton and Connecting Railroad, basanite; 
 at the quarries on Frankford Creek, stilbite, molybdenite, hornblende; 
 on the Connecting Railroad, wad, earthy cobalt ; at Chestnut Hill, 
 magnetite, green mica, chalcopyrite, fluorite. 
 
 FAIRMOUNT WATER-WORKES.—In the quarries opposite Fairmount, 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 355 
 
 autunite! torbernite, crystals of feldspar, beryl, pseudomorphs after 
 beryl, tourmaline, albite, wad, menaccanite. 
 
 GorGAs’s and CREASE’s LANE.—Tourmaline, cyanite, staurolito, 
 hornstone. 
 
 Near GERMANTOWN.—Black tourmaline, laumontite, apatite ; York 
 Road, tourmaline, beryl. ' 
 
 HESTONVILLE.—Alunogen, iron alum, orthoclase. 
 
 Hervr’s Minu.—Alunogen, tourmaline, cyanite, titanite. 
 
 MANAYUNK.—At the soapstone quarries above Manayunk, talc, 
 steatite, chlorite, vermiculite, anthophyllite, staurolite, dolomite, apa- 
 tite, asbestus, brown spar, epsomite. 
 
 MEGARGEE’S Paper-mill.—Staurolite, titanic iron, hyalite, apatite, 
 green mica, iron garnets in great abundance. 
 
 McKINNEY’s QUARRY, on Rittenhouse Lane.—Feldspar, apatite, stil- 
 bite, natrolite, heuwlandite, epidote, hornblende, erubescite, malachite. 
 
 SCHUYLKILL FALis.—Chabazite, titanite, fluorite, epidote, musco- 
 vite, tourmaline, prochlorite. 
 
 SCHUYLKILL CO,.—TAMAQUA, near POTTSVILLE, in coal mines.—- 
 Kaolinite. 
 
 YORK CO.—Bornite, rutile in slender prisms in granular quartz. 
 
 DELAW ARE. 
 
 NEWCASTLE CO.—BRrANDYWINE SpPrRINGS.—BPucholzite, fibrolite 
 abundant, sahlite, pyroxene; Brandywine Hundred, muscovite, en- 
 closing reticulated magnetite. 
 
 Drxon’s FELDSPAR QUARRIES, six miles N. W. of Wilmington 
 (quarries worked for the manufacture of porcelain).—Adularia, albite, 
 oligoclase, beryl, apatite, cinnamon-stone / / magnesite, serpentine, as- 
 bestus, black tourmaline / (rare), indicolite / (rare), sphene in pyroxene, 
 cyanite. 
 
 Dupont’s PowDER Miuus.—‘‘ Hypersthene.” 
 
 EASTBURN’S LIMESTONE QUARRIES, near the Pennsylvania line.— 
 Tremolite, bronette. 
 
 QUARRYVILLE.—Garnet, spodumene, fibrolite. 
 
 Near NEWARK, on the railroad.—Spherosiderite on drusy quartz, 
 jasper (ferruginous opal), cryst. spathic iron in the cavities of cellular 
 quartz. 
 
 Way’s QuARRY, two miles south of Centreville.—Feldspar in fine 
 cleavage masses, apatite, mica, deweylite, granular quarte. 
 
 WitMminetTon.—In Christiana quarries, metalloidal diallage. 
 
 KENNETT TURNPIKE, near Centreville.—Cyanite and garnet. 
 
 HARTFORD CO.—Deweylite. 
 
 KENT CO.—Near MIDDLETOWN, in Wm. Polk’s marl pits.— Vivi- 
 anite | 
 
 On CHESAPEAKE AND DELAWARE CANAL.—Retinasphalt, pyrite, 
 amber. 
 
 SUSSEX CO,—Near CAPE HENLOPEN.—Vivianite. 
 
 MARYLAND. 
 
 BALTIMORE (Jones’s Falls, 14 mile from B.).—Chabazite (haydenite), 
 heulandite (beaumontite of Levy), pyrite, lenticular carbonate of iron, 
 mica, stilbite, 
 
356 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 Sixteen miles from Baltimore, on the Gunpowder. — Graphite. 
 
 Twenty-three miles from B., on the Gunpowder.— Tale. 
 
 Twenty-five miles from B., on the Gunpowder.—Magnetite, sphene, 
 ycnite. 
 
 Thirty miles from B., in Montgomery Co., on farm of 8. Eliot.— 
 Gold in quartz. 
 
 Hight to twenty miles north of B., in limestone.—TZremolite, augite, 
 pyrite, brown and yellow tourmaline. 
 
 Fifteen miles north of B.—Sky-blue chalcedony in granular lime- 
 stone. 
 
 Highteen miles north of B., at Scott’s mills.—Magnetite, cyanite. 
 
 BARE Hr1s.—Chromite, asbestus, tremolite, talc, hornblende, ser- 
 pentine, chalcedony, meerschaum, baltimorite, chalcopyrite, mag- 
 netite. 
 
 CAPE SABLE, near Magothy R.—Amber, pyrite, alum slate. 
 
 CARROLL Co.—Near Sykesville, Liberty Mines, gold, maenetite, 
 pyrite (octahedrons), chalcopyrite, linneeite (carrollite) ; at Patapsco 
 Mines, near Finksburg, bornite, malachite, siegenite, linnaite, reming- 
 tonite, magnetite, chalcopyrite ; at Mineral Hill mine, bornite, chalco- 
 pyrite, ore of nickel (see above), gold, magnetite. 
 
 Crcr Co., north part.—Chromite in serpentine. 
 
 Coortown, Harford Co.—Olive-colored towrmaline, diallage, tale of 
 green, blue, and rose colors, ligniform asbestus, chromite, serpentine. 
 
 DEER CREEK.—Magnetite / in chlorite slate. 
 
 FREDERICK Co.—Old Liberty mine, near Liberty Town, black cop- 
 per, malachite, chalcocite, specular iron ; at Dollyhyde mine, bornite, 
 chalcopyrite, pyrite, argentiferous galenite in dolomite. 
 
 MONTGOMERY Co.— Oxide of manganese. 
 
 SoMERSET and WORCESTER COS., north part.—Bog-iron ore, vivi- 
 anite. 
 
 Sr. Mary’s RIver.—Gypsum / in clay. 
 
 PYLESVILLE, Harford Co.—Asbestus mine. 
 
 VIRGINIA, WEST VIRGINIA, AND DISTRICT OF COLUMBIA. 
 
 ALBEMARLE Co., a little west of the Green Mts.—Steatite, graphite, 
 galenite. 
 
 Amurrst Co.—Along the west base of Buffalo Ridge, copper ores ; 
 on N. W. slope of Friar Mtn., allanite, magnetite, zircon, sipylite. 
 
 Auausta Co.—At Weyer’s (or Weir’s) cave, sixteen miles north- 
 east of Staunton, and eighty-one miles northwest of Richmond, cal- 
 cite, stalactites. 
 
 BucktncHam Co.—Gold at Garnett and Moseley mines, also, pyrite, 
 pyrrhotite, calcite, garnet ; at Eldridge mine (now London and Vir- 
 ginia mines) near by, and the Buckingham mines near Maysville, gold, 
 auriferous pyrite, chalcopyrite, tennantite, barite ; cyanite, tourmaline, 
 actinolite. 
 
 CHESTERFIELD Co.—Near this and Richmond Co., bituminous coal, 
 native coke. 
 
 CULPEPPER Co., on Rapidan River.—Gold, pyrite. 
 
 FRANKLIN Co.—Grayish steatite. 
 
 FAUQUIER Co., Barnett’s mills,—Asbestus, gold mines, barite, cal- 
 cite. 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS, 9357 
 
 FLUVANNA Co.—Gold at Stockton’s mine; also tetradymite, at 
 ‘Tellurium mine,” 
 
 PHENIX COPPER Mines.—Chalcopyrite, etc. 
 
 GEORGETOWN, D. C.—Rutile. 
 
 GoocHLAND Co.—Gold mines (Moss and Busby’s). 
 
 HARPER’S FeRRy, on both sides of the Potomac.—Thuringite (owen. 
 ite) with quartz. 
 
 JEFFERSON Co., at Shepherdstown.—Fluor. 
 
 KANAWHA Co.—At Kanawha, petroleum, brine springs, cannel coal. 
 
 Loupon Co.— Tabular quartz, drase, pyrite, tale, chlorite, soapstone, 
 asbestus, chromite, actinolite, quartz crystals ; micaceous tron, bornite, 
 malachite, epidote, near Leesburg (Potomac mine), 
 
 Louisa Co.—Walton gold mine, gold, pyrite, chalcopyrite, argen- 
 tiferous galenite, siderite, blende, anglesite; boulangerite, blende (at 
 Tinder’s mine). 
 
 NELSON Co,—Galenite, chalcopyrite, malachite. 
 
 ORANGE Co.— Western part, Blue Ridge, specular iron ; gold at the 
 Orange Grove and Vaucluse gold mines, worked by the “ Freehold ” 
 and “ Liberty ” Mining Companies. 
 
 RocKBRIDGE Co., three miles southwest of Lexington.—Barite, 
 strengite. 
 
 SHENANDOAH Co., near Woodstock.—Fluorite. 
 
 MT. ALTO, Blue Ridge.—Argillaceous iron ore, 
 
 SPOTTSYLVANIA Co., two miles northeast of Chancellorville.—(Cy- 
 anite ; gold mines at the junction of the Rappahannock and Rapidan ; 
 on the Rappahannock (Marshall mine); Whitehall mine, affording 
 also tedradymite. 
 
 STAFFORD Co., eight or ten miles from Falmouth.--Micaceous iron, 
 gold, tedradymite, silver, galenite, vivianite. 
 
 WASHINGTON Co., eighteen miles from Abingdon.—Rock salt with 
 gypsum. 
 
 WYTHE Co. (Austin’s mines).—Cerussite, mintum, plumbic ochre, 
 blende, calamine, galenite, graphite. — 
 
 On the Potomac, twenty-five miles north of Washington. City.—Na- 
 tive sulphur in gray compact limestone. 
 
 NORTH CAROLINA. 
 
 ASHE Co.—Malachite, chalcopyrite. 
 
 BUNCOMBE Co. (now called Madison Co.)\—Corundum (from a boul- 
 der), margarite, corundophilite, garnet, chromite, barite, fluorite, ru- 
 tile, iron ores, manganese, zircon ; at Swananoa Gap, cyanite. 
 
 BuRKE Co.—Gold, monazite, zircon, beryl, corundum, garnet, sphene, 
 graphite, iron ores, tetradymite, montanite (hydrous bismuth tellurate). 
 
 CABARRUS Co.—Phenix Mine, gold, barite, chalcopyrite, auriferous 
 pyrite, quartz pseudomorph after barite, tetradymite, montanite ; Pi- 
 oneer mines, gold, limonite, pyrolusite, barnhardite, wolfram, scheelite, 
 cuprotungstite, tungstite, diamond, chrysocolla, chalcocite, molybde- 
 nite, chalcopyrite, pyrite ; White mine, needle ore, chalcopyrite, ba- 
 rite ; Long and Muse’s mine, argentiferous galenite, pyrite, chalcopy- 
 rite, limonite ; Boger mine, tetradymite ; Fink mine, valuable copper 
 ores; Mt. Makins, tetrahedrite, magnetite, talc, blende, pyrite, prous- 
 
 tite, galenite ; Bangle mine, scheelite, 
 
358 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 CALDWELL Co.—Chromite. 
 
 CyatHam Co.—Mineral coal, pyrite, chloritoid. 
 
 CHEROKEE Co.—lIron ores, gold, galenite, corundum, rutile, cyanite, 
 damonite. 
 
 CLEVELAND Co,—White i’lains, quartz, crystals, smoky quartz, tour- 
 maline, rutile in quartz. 
 
 Chay Co.—At the Cullakenee mine and elsewhere, corundum (pink), 
 zoisite, tourmaline, margarite, willcoxite, dudleyite. 
 
 Davipson Co.—King’s, now Washington mine, native silver, cerus- 
 site, anglesite, scheelite, pyromorphite, galenite, blende, malachite, 
 black copper, wavellite, garnet, stilbite ; five miles from Washington 
 mine, on Faust’s farm, gold, tetradynite, oxide of bismuth and tellu- 
 rium, montanite, chalcopyrite, limonite, spathic iron, epidote ; near 
 Squire Ward’s, gold in crystals, electrum. . 
 
 FRANKLIN Co.—At Partiss mine, diamonds. — 
 
 Gasron Co.—Iron ores, corundum, margarite; near Crowder’s Moun- 
 tain (in what was formerly Lincoln Co.), lazulite, cyanite, garnet, gra- 
 phite ; also twenty miles northeast, near south end of Clubb’s Moun- 
 tain, lazulite, cyanite, tale, rutile, topaz, pyrophyllite ; King’s Moun- 
 tain (or Briggs) mine, native tellurium, altaite, tedradymite, monta- 
 nite. 
 
 GurILFoRD Co.—MecCulloch copper and gold mine, twelve miles from 
 Greensboro’, gold, pyrite, chalcopyrite (worked for copper), quartz, sid- 
 erite ; copper ore at the old Fentress mine ; at Deep River, compact 
 pyrophyllite (worked for slate-pencils), } 
 
 HAywoop Co.—Corundum, margarite, damourite. 
 
 HENDERSON Co.—Zircon, sphene (xanthitane). 
 
 Jackson Co.—Alunogen ? at Smoky Mountain ; at Webster, serpen- 
 tine, chromite, genthite, chrysolite, tale 5 Hoghalt Mountain, pink co- 
 rundum, margarite, tourmaline. 
 
 LrIncoLn Co.—Diamond ; at Randleman’s, amethyst, rose quartz. 
 
 Macon Co.—Franklin, Culsagee mine, corundum, spinel, diaspore, 
 tourmaline, damourite, prochlorite, culsageeite, kerrite, maconite. 
 
 McDowE.u Co.—Brookite, monazite, corundum in small crystals, 
 red and white, zircons, garnet, beryl, sphene, xenotime, rutile, elastic 
 sandstone, iron ores, pyromelane, tetradymite, montanite. 
 
 Mapison Co.—Twenty miles from Asheville, corundum, margarite, 
 chlorite. 
 
 MECKLENBURG Co.—Near Charlotte (Rhea and Cathay mines) and 
 elsewhere, chalcopyrite, gold ; chalcotrichite at McGinn’s mine; barn- 
 hardtite near Charlotte; pyrophyllite sn Cotton Stone Mountain, dia- 
 mond; Flowe mine, scheelite, wolframite ; Todd’s Branch, monazite. 
 
 MrrcHELi Co.—At the Wiseman mica mine, muscovite, samarsktite, 
 hatchettolite, euxenite, columbite, rogersite, uraninite, gummite, Urd- 
 ie torbernite, autunite ; at Grassy Creek mine, muscovite, samars- 
 cites 
 
 MontcomERy Co.—Steele’s mine, ripidolite, albite. 
 
 lotte, and fourteen from Salisbury, gold, auriferous pyrite; ten miles 
 from Salisbury, feldspar in crystals, bismuthinite. 
 
 RUTHERFORD Co.—Gold, graphite, bismuthic gold, diamond, euclase, 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 359 
 
 pseudomorphous quartz? chalcedony, corundum in small crystals, epi- 
 dote, pyrope, brookite, zircon, monazite, rutherfordite, samarskite, 
 quartz crystals, itacolumyte ; on the road to Cooper’s Gap, cyanite. 
 
 STOKES and SurRy Cos,—Iron ores, graphite. 
 
 Union Co.—Lemmond gold mine, eighteen miles from Concord (at 
 Stewart’s and Moore’s mine), gold, quartz, blende, argentiferous gale- 
 nite (containing 29°4 oz. of gold and 86°5 oz. of silver to the ton, Genth), 
 pyrite, some chalcopyrite. 
 
 Yancey Co.—/ron ores, amianthus, chromite, garnet (spessartite), 
 samarskite, columbite. 
 
 SOUTH CAROLINA. 
 
 - ABBEVILLE Dist.—Oakland Grove, gold (Dorn mine), galenite, pyro- 
 morphite, amethyst, garnet. 
 
 ANDERSON Dist.—At Pendleton, actinolite, galenite, kaolin, towrma- 
 line. 
 
 CHARLESTON.—Selenite. 
 
 CHEOWEE VALLEY.—Galenite, tourmaline, gold. 
 
 CHESTERFIELD Dist.—Gold (Brewer’s mine), talc, chlorite, pyrophy]- 
 lite, pyrite, native bismuth, bismuth carbonate, red and yellow ochre, 
 whetstone, enargite. 
 
 DARLINGTON.—Kaolin. 
 
 EDGEFIELD D1sT.—Psilomelane. 
 
 GREENVILLE DIsT.—Galenite, pyromorphite, kaolin, chalcedony in 
 buhrstone, beryl, plumbago, epidote, towrmaline. 
 
 Kersuaw Dist.—futile. 
 
 LANCASTER Dist.—Gold (Hale’s mine), talc, chlorite, cyanite, ita- 
 columyte, pyrite ; gold also at Blackman’s mine, Massey’s mine, 
 Ezell’s mine. 
 
 LAURENS Dist.—Corundum, damourite. 
 
 NEWBERRY Dist.—Leadhillite. 
 
 PickENS Dist.—Gold, manganese ores, kaolin. 
 
 RIcHLAND Dist.—Chiastolite, novaculite. 
 
 SPARTANBURG Dist.—Magnetite, chalcedony, hematite ; at the Cow- 
 pens, limonite, graphite, limestone, copperas; Morgan mine, leadhil- 
 lite, pyromorphite, cerussite. 
 
 SumTER Dist.—Agate. 
 
 Union Dist.—Fairforest gold mines, pyrite, chalcopyrite. 
 
 York Dist.—Limestones, whetstones, witherite, barite, tetrady- 
 mite. 
 
 GEORGIA. 
 
 BURKE AND ScRIVEN Cos.—Hyalite. 
 
 CHEROKEE Co.—At Canton Mine, chalcopyrite, galenite, claustha- 
 lite, plumbogummite, hitchcockite, arsenopyrite, lanthanite, harrisite, 
 cantonite, pyromorphite, automolite, zinc, staurolite, cyanite ; at Ball- 
 Ground, spodumene. 
 
 CLARK Co., near Clarksville.—Gold, xenotime, zircon, rutile, cyanite, 
 hematite, garnet, quartz. 
 
 DADE Co.—Halloysite, near Rising Fawn, 
 
 Fannin Co.—Staurolite / chalcopyrite, 
 
360 ‘ SUPPLEMENT TO DESCRIPTIONS OF SPECIES. ~ 
 
 Harersuam Co.—Gold, pyrite, chalcopyrite, galenite, hornblende, 
 garnet, quartz, kaolinite, soapstone, chlorite, rutile, iron ores, tourma- 
 line, staurolite, zircon. 
 
 Hay Co.—Gold, quartz, kaolin, diamond. 
 
 Hancock Co.—Agate, chalcedony. 
 
 Harp Co.—Molybdite, quartz. 
 
 Ler Co.—At the Chewacla Lime Quarry, dolomite, barite, guartz 
 crystals. 
 
 Lincoun Co.—Lazulite! ! rutile! / hematite, cyanite, manaccanite, 
 pyrophyllite, gold, itacolumyte rock. 
 
 LowNbDEs Co.—Corundum. 
 
 LumpPrtin Co.—At Field’s gold mine, near Dahlonega, gold, tetrady- 
 mite, pyrrhotite, chlorite, menaccanite, allanite, apatite. 
 
 Rapun Co.—Gold, chalcopyrite. 
 
 . SPAULDING Co.—Tetradymite. 
 WASHINGTON Co., near Saundersville.— Wavellite, fire opal. 
 
 ALABAMA. 
 
 Benton Co.—Antimonial lead ore (boulangerite ?) 
 
 Briss Co., Centreville.—Jron ores, marble, barite, coal, cobalt. 
 
 CHAMBERS Co.—Near La Fayette, steatite, garnets, actinolite, chlo- 
 rite; east of Oak Bowery, steatite. 
 
 Curuton Co—Muscovite, graphite, limonite. 
 
 CLEBURNE Co.—At Arbacoochee mine, gold, pyrite, and three miles 
 distant cyanite, garnets ; at Wood’s min, black copper, azurite, chalco- 
 pyrite, pyrite. 
 
 CLAY Co.—<Steatite ; near Delta and Ashland, muscovite. 
 
 Coosa Co.—Tantalite, gold, muscovite. 
 
 RANDOLPH Co.—Gold, pyrite, tourmaline, muscovite ; at Louina, 
 porcelain clay, garnet. 
 
 TALLADEGA Co.—Limonite. 
 
 TALLAPOOSA Co., at Dudleyville.—Corundum, margarite, ripidolite, 
 spinel, tourmaline, actinolite, steatite, asbestus, chrysolite, damourite, 
 corundum altered to tourmaline (crvstals of the latter containing a 
 nucleus of the former) and also other pseudomorphs, including, at 
 Dudleyville, dudleyite. 
 
 TuSKALOOSA Co.—Ooal, galenite, pyrite, vivianite, limonite, calcite, 
 dolomite, cyanite, steatite, quartz crytals, manganese ores. 
 
 FLORIDA. 
 
 Near Tampa: Bay.—Limestone, sulphur springs, chalcedony, 
 _ carnelian, agate, silicified shells and corals. 
 
 KENTUCKY. 
 
 ANDERSON Co. —Galenite, barite. 
 
 CLinton Co.—Geodes of quartz. 
 
 CRITTENDEN Co.—Galenite, fluorite, calcite. 
 
 CUMBERLAND Co.—At Mammoth Cave, gypsum rosettes! calcite, 
 stalactites, nitre, epsomite. 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 361 
 
 FAYETTE Co.—Six miles N. E. of Lexington, galenite, barite, 
 witherite, blende. 
 
 LIVINGSTON Co., near the line of Union Co.—Galenite, chalcopyrite, 
 large vein of fluorite. 
 
 MERCER Co.—At McAfee, fluorite, pyrite, calcite, barite, celestite. 
 
 OWEN Co.—-Galenite, barite. 
 
 TENNESSEE. 
 
 BrRown’s CREEK.—Galenite, blende, barite, celestite. 
 
 CARTER Co., foot of Roan Mt.—-Sahlite, magnetite. 
 
 CLAIBORNE Co.—Calamine, galenite, smithsonite, chlorite, steatite, 
 magnetite. 
 
 Cocke Co., near Bush Creek.—Cacoxenite? kraurite, iron sinter, 
 stilpnosiderite, brown hematite. 
 
 Davipson Co.—-Selenite, with granular and snowy gypsum, or ala- 
 baster, crystallized and compact anhydrite, fluorite in crystals? calcite 
 in crystals. Near Nashville, blue celestite (crystallized, fibrous, and 
 radiated), with barite in limestone. Haysboro’, galenite, blende, with 
 barite as the gangue of the ore. 
 
 Dickson Co.—Manganite. 
 
 JEFFERSON Co.—Calamine, galenite, fetid barite. 
 
 Knox Co.—Magnesian limestone, native iron, variegated marbles / 
 
 Maury Co.—Wavellite in limestone. 
 
 MorGANn Co.—Epsom salt, nitrate of lime. 
 
 Pouk Co., Ducktown mines, southeast corner of State.—Melaconite, 
 chalcopyrite, pyrite, native copper, bornite, rutile, zoisite, galenite, har- 
 risite, alisonite, blende, pyroxene, tremolite, sulphates of copper and 
 tron in stalactites, allophane, rahtite, chalcocite (ducktownite), chal- 
 cotrichite, azurite, malachite, pyrrhotite, limonite. 
 
 Roan Co., easterly declivity of Cumberland Mts.—Wavellite in 
 limestone. 
 
 SEVIER Co., in caverns.—Epsomite, soda alum, nitre, nitrate of 
 calcium, breccia marble. 
 
 Sm1TH Co.—Fluorite. 
 
 Smoky Mr., on declivity.—Hornblende, garnet, staurolite. 
 
 WHITE Co.—WNitre. 
 
 OHIO. 
 
 BAINBRIDGE (Copperas Mt., a few miles east of B.).—Calcite, barite, 
 pyrite, copperas, alum. 
 
 CANFIELD.—Gypsum / 
 
 Duck CREEK, Monroe Co.—Petroleum. 
 
 LAKE Erin.—Strontian Island, célestite/ Put-in-Bay Island, celestite / 
 sulphur ! calcite. 
 
 LIVERPOOL.—Petroleum. 
 
 Marierra.—Argillaceous iron ore: iron ore abundant also in Scioto 
 and Lawrence Cos. 
 
 OTrrawa Co.—Gypsum, 
 
 POLAND.—Gypsum / 
 
362 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 MICHIGAN. 
 
 Brest (Monroe Co.).—Calcite, amethystine quartz, apatite, celestite. 
 
 GRAND Raprps.—Selenite, fib. and granular gypsum, calcite, dolomite, 
 anhydrite. 
 
 LAKE SuPpeRioR Mrninc Reeion.—The four principal regions are 
 Keweenaw Point, Isle Royale, the Ontonagon, and Portage Lake. 
 The mines of Keweenaw Point are along two ranges of elevation, one 
 known as the Greenstone Range, and the other as the Southern or 
 Bohemian Range (Whitney). The copper occurs in the trap or amyg- 
 daloid, and in the associated conglomerate. Native copper / native 
 silver / chalcopyrite, horn silver, tetrahedrite, manganese ores, epi- 
 dote, prelnite, laumontite, datolite, heulandite, orthoclase, analcite, cha- 
 bazite, compact datolite, chrysocolla, mesotype (Copper Falls mine), 
 leonhurdite (ib.), analeite (ib.), apophyllite (at Cliff mine), wollastonite 
 (ib.), calcite, quartz (in crystals at Minnesota mine), compact datolite, 
 orthoclase (Superior mine), saponite, melaconite (near Copper Harbor, 
 but exhausted), chrysocolla; on Chocolate River, galenite and sul- 
 phide of copper ; chalcopyrite and native copper at Presq’Isle ; at 
 Albion mine, domeykite ; at Prince Vein, barite, calcite amethyst ; at 
 Albany and Boston mine, Portage Lake, prehnite, analeite, orthoclase, 
 cuprite ; at Sheldon location, domeykite, whitneyite, algodonite ; Quincy 
 mine, calcite, compact datolite. At the Spur Mountain iron mine 
 (magnetite), chlorite pseudomorph after garnet ; Isle Royale, datolite, 
 prehnite. 
 
 MARQUETTE.—Manganite, galenite ; twelve miles west at Jackson 
 Mt., and other mines, hematite, limonite, gothite / magnetite, jasper. 
 
 Monroxr.—Aragonite, apatite. 
 
 Pornt AUX PEAUX (Monroe Co )--Amethystine quartz, apatite, celes- 
 tite, calcite. . 
 
 Saginaw Bay.—At Alabaster, gypsum. 
 
 Srony Pornt (Monroe Co.)—Apatite, amethystine quartz, celestite, 
 calcite. 
 
 ILLINOIS. 
 
 GALLATIN Co., on a branch of Grand Pierre Creek, sixteen to thirty 
 miles from Shawneetown, down the Ohio, and from half to eight 
 miles from this river.— Violet fluorite! in carboniferous limestone, 
 barite, galenite, blende, brown iron ore. 
 
 Hancock Co.—At Warsaw, quartz geodes containing calcite! chal- 
 cedony, dolomite, blende / brown spar, pyrite, aragonite, gypsum, bitu- 
 men. 
 
 HARDIN Co.—Near Rosiclare, calcite, galenite, blende ; five miles 
 back from Elizabethtown, bog iron ; one mile north of the river, be- 
 tween Elizabethtown and Rosiclare, nitre. 
 
 Jo Daviess Co.—At Galena, galenite, calcite, pyrite, blende ; at Mars- 
 den’s diggings, galenite / blende, cerussite, marcasite in stalactitic forms, 
 
 yrite. 
 
 JoLtieT.—Marble. 
 
 Qurincy.— Calcite! pyrite. 
 
 ScaLes MounD.—Barite, pyrite. 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 363 
 
 INDIANA. 
 
 LIMESTONE CAVERNS ; Corydon Caves, etc.—Hpsom salt. 
 
 In most of the southwest counties, pyrite, iron sulphate, and feather 
 alum ; on Sugar Creek, pyrite and tron sulphate ; in sandstone of Lloyd 
 Co., near the Ohio, gypsum ; at the top of the blue limestone forma- 
 tion, brown spar, calcite. ; 
 
 LAWRENCE Co.—Spice Valle, kaolinite (=indianaite). 
 
 MINNESOTA. 
 
 Nortu SHore oF L. SUPERIOR (range of hills running nearly north- 
 east and southwest, extending from Fond du Lac Superieure to the 
 Kamanistiqueia River in Upper Canada).—Scolecite, apophyllite, preh- 
 nite, stilbite, laumontite, heulandite, harmotome, thomsonite, fluorite, 
 barite, tourmaline, epidote, hornblende, calcite, quartz crystals, pyrite, 
 magnetite, steatite, blende, black oxide of copper, malachite, native 
 copper, chalcopyrite, amethystine quartz, ferruginous quartz, chalce- 
 dony, carnelian, agate, drusy quartz, hyalite? fibrous quartz, jasper, 
 prase (in the debris of the lake shore), dogtooth spar, augite, native 
 silver, spodumene? chlorite ; between Pigeon Point and Fond du Lae, 
 near Baptism River, saponite (thalite) in amygdaloid. 
 
 KertTLe River Trap RANGE.—Epidote, nail-head calcite, amethys- 
 tine quartz, calcite, undetermined zeolites, saponite. 
 
 STILLWATER.—Blende. 
 
 FALLS OF THE ST. CRorx.—Malachite, native copper, epidote, nail- 
 head spar (calcite). 
 
 Rainy LAKE.—Actinolite, tremolite, fibrous hornblende, garnet, py- 
 rite, magnetite, steatite. 
 
 WISCONSIN. . 
 
 Bie BuLL FALLS (near).—Bog iron. 
 
 BLUE MounDs.—Cerussite. 
 
 HAZEL GREEN.—Calcite. 
 
 Lac DU FLAMBEAU R.—Garnet, cyanite. 
 
 LEFT-HAND R. (near small tributary).—Malachite, chalcocite, native 
 copper, cuprite, malachite, epidoto, chlorite? quartz crystals. 
 
 LINDEN.—Galenite, smithsonite, hydrozincite. 
 
 MINERAL POINT and vicinity.—Copper and lead ores, chrysocolla, 
 azurite! chalcopyrite, malachite, galenite, cerussite, anglesite, blende, 
 pyrite, barite, calcite, marcasite, smithsonite/ (including pseudomorphs 
 after calcite and blende), (so-called “dry-bone’’), calamine, bornite, 
 hydrozincite. 
 
 MoNTREAL RIVER PORTAGE.—Galenite in gneissoid granite. 
 
 Sauk Co.—Hematite, malachite, chalcopyrite. 
 
 SHULLSBURG.—Galenite/ blende, pyrite ; at Emmet’s digging, ga- 
 tenite and pyrite. 
 
 IOWA. 
 
 Du BuquE LEAD MINES, and elsewhere.—Galenite! calcite, blende, 
 black oxide of manganese ; at Ewing’s and Sherard’s diggings, smith- 
 
364 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 sonite, calamine ; at Des Moines, quartz crystals, selenite ; Makoqueta 
 R., limonite ; near Durango, galenite. 
 
 CEDAR RIVER, a branch of the Des Moines.—Séelenite in crystals, in 
 the bituminous shale of the coal measures ; also elsewhere on the Des 
 Moines, gypsum abundant ; argillaceous iron ore, spathic iron ; cop- 
 peras in crystals on the Des Moines, above the mouth of Saap and else- 
 where, pyrite, blende. 
 
 Fort Dopas.— Celestite. 
 
 MAKoQuETA.—Hematite. 
 
 New GALENA.—Octahedral galenite, anglesite. 
 
 MISSOURI. 
 
 For the distribution of the lead mines see page 147. The number 
 of minerals associated with the lead ore varies greatly in the different 
 lead regions. Mine la Motte, and some old openings in Madison Co., 
 are peculiar in affording cobalt and nickel ores abundantly. At Granby 
 and other mines the chief zine ore is calamine, or the silicate of zinc, 
 while in the mines of Central and Southwest Missouri it is compara- 
 tively rare, and smithsonite is the prominent ore—as is the case in 
 Wisconsin ; yet calamine is the most abundant zine ore in the State. 
 As stated by A. Schmidt, the zinc ore, in each case, is found as a sec- 
 ondary product to sphalerite (blende) ; the cerussite often coats the 
 galenite, or has its forms, indicating thus its source ; the limonite is 
 also secondary, and has come in mainly through the oxidation of py- 
 rite. At the Granby mines, the calamine is called, among the miners, 
 “Black Jack ;” blende, ‘‘ Resin Jack ; »” a white massive smithsonite, 
 ‘«‘ White Jack ;” and the cerussite is the ‘Dry Bone;” thus departing 
 from ordinary miners’ usage. Gold has been found in the drift sands 
 of Northern Missouri (Broadhead). 
 
 ApDAIR Co.—Gothite in calcite. 
 
 Barton Co.—Pickeringite as an effloresence on sandstone. 
 
 CHARITON Co.—Near Salisbury, gypsum in coal beds. 
 
 CoLE Co.—At Old Circle Diggings and elsewhere, barite! galenite, 
 chalcopyrite, malachite, azurite, pyrite, calcite, calamine, sphalerite. 
 
 Iron Co.—At Pilot Knob and Shepherd Mountain, hematite, mag- 
 netite, limonite, manganese oxide, bog manganese. 
 
 JASPER Co. (adjoins 8. E. Kansas).—At J oplin mines, galena! spha- 
 lerite, pyrite, cerussite, calamine, dolomite, bitumen. 
 
 JEFFERSON Co.—At Valle’s, galenite ! cerussite, anglesite, calamine, 
 smithsonite, sphalerite, hydrozincite, chalcopyrite, malachite, azurite, 
 pyrite, barite, witherite, limonite. At Frumet mines, 83 miles from 
 De Soto R. R. station, galena, barite/ smithsonite/ pyrite, limnite. 
 
 MaprIson Co.—At Mine la Motte, galenite! cerussite ! siegenite (nickel- 
 linneite), smaltite, asbolite (earthy black cobalt ore), bog manganese, 
 chalcopyrite, malachite, caledonite, plumbogummite, wolframite. 
 
 MorGan Co.—At Cordray Diggings, galena, blende, barite. 
 
 Newton Co. (adjoins 8. E. Kansas).—At Granby mines, galenite/ 
 cerussite, calamine! sphalerite, smithsonite, hydrozincite, greenockite 
 (on sphalerite), pyromorphite, dolomite, calcite, bitumen. 
 
 PULASKI Co.—In caves, nitre. 
 
 Sr, FRANCOIS Co,—Iron Mountain, hematite, limonite, 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 365 
 
 St. Lours Co.—Near St. Louis, millerite (in the Subcarboniferous 
 St. Louis limestone, largely a magnesian limestone) with calcite! ba- 
 rite, fluorite. 
 
 WASHINGTON Co.—-At Potosi (Mine 4 Burton), galenite, cerussite, 
 anglesite, barite, calcite. 
 
 ARKANSAS. 
 
 BATESVILLE.—In bed of White R., some miles above Batesville, 
 gold. 
 
 GREEN Co.—Near Gainesville, lignite. 
 
 Hor Sprines Co.—At Hot Springs, wavellite, thuringite; Magnet 
 Cove, brookite ! schorlomite, eleolite, magnetite, quartz, green coccolite, 
 garnet, apatite, perofskite (hydrotitanite), rutile, ripidolite, thomsonite 
 (ozarkite), microcline, egirite, protovermiculite. 
 
 INDEPENDENCE Co.—Lafferay Creek, psilomelane. 
 
 LAWRENCE Co.—Hoppe, Bath, and Koch mines, smithsonite, dolo- 
 mite, galenite ; nitre. 
 
 MARION Co.—Wood’s mine, smithsonite, hydrozincite (marionite), 
 galenite ; Poke bayou, braunite ? 
 
 MONTGOMERY Co.—Variscite. 
 
 OUACHITA SPRINGS.— Quartz? whetstones. 
 
 Puuaski Co.—Kellogg mine, 10 m. uorth of Little Rock, tetrahedrite, 
 tennantite, nacrite, galenite, blende, quartz. 
 
 CALIFORNIA. 
 
 The principal gold mines of California are in Tulare, Fresno, Mari- 
 posa, Tuolumne, Calaveras, El Dorado, Placer, Nevada, Yuba, Sierra, 
 Butte, Plumas, Shasta, Siskiyou, and Del Norte counties, although 
 gold is found in almost every county of the State. The gold occurs in 
 quartz, associated with sulphides of iron, copper, zinc, and lead ; in 
 Calaveras and Tuolumne counties, at the Mellones, Stanislaus, Golden 
 Rule, and Rawhide mines, associated with tellurides of gold and sil- 
 ver ; it is also largely obtained from placer digrings, and further it is 
 found in beach washings in Del Norte and Klamath counties. 
 
 The copper mines are principally at or near Copperopolis, in Cala. 
 veras County; near Genesee Valley, in Plumas County; near Low 
 Divide, in Del Norte County ; on the north fork of Smith’s River ; at 
 Soledad, in Los Angeles county. 
 
 The mercury mines are at or near New Almaden and North Al- 
 maden, in Santa Clara County ; at New Idria and San Carlos, Monterey 
 County ; in San Luis Obispo County ; at Pioneer mine, and other locali- 
 ties in Lake County ; in Santa Barbara County. 
 
 ALAMEDA Co.—Diabolo Range, magnesite. 
 
 ALPINE Co.—Morning Star mine, enargite, stephanite, polybasite, 
 barite, quartz, pyrite, tetrahedite, pyrargyrite. 
 
 AMADOR Co.—At Volcano, chalcedony, Ayalite ; Lone Valley, lonite ; 
 Fiddletown, diamond. 
 
 Burre Co.—Cherokee Flat, diamond, platinum, iridosmine. 
 
 CALAVERAS Co.—Copperopolis, chalcopyrite, malachite, azurite, ser- 
 pentine, picrolite, native copper ; near Murphy’s, jasper, opal ; albite, 
 with gold and pyrite; Mellones mine, calaverite, petzite. 
 
366 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 Conrra-Costa Co.—San Antonio, chalcedony. 
 
 DEL Norte Co.—Crescent City, agate, carnelian; Low Divide, chal- 
 copyrite, bornite, malachite ; on the coast, iridosmine, platinum, gold, 
 zircon, diamond. 
 
 Ex, Dorapo Co.—Pilot Hill, chalcopyrite; near Georgetown, hessite, 
 from placer diggings ; Roger’s Claim, Hope Valley, grossular garnet, 
 in copper ore ; Coloma, chromite ; Spanish Dry Diggings, gold ; Gran- 
 ite Creek, roscoelite, gold ; Forest Hill, diamond; Cosumnes mine, 
 molybdenite. 
 
 FREsNo Co.—Chowchillas, andalusite ; King’s River, bornite. 
 
 HumpBoipt Co.—Cryptomorphite. 
 
 Inyo Co.—Inyo district, galenite, cerussite, anglesite, barite, ataca- 
 mite, calcite, grossular garnet / Surprise Mine, tetrahedrite ; Kear- 
 sarge mine, silver ores ; Cerro Gordo, wulfenite. 
 
 Kern Co.—Green Monster mine, cuproscheelite. 
 
 LAKE Co.—Borax Lake, boraw/ sassolite, glauberite ; Pioneer mine, 
 cinnabar, native mercury, selenide of mercury ; near the Geysers, 
 sulphur, hyalite ; Redington mine, metacinnabarite ; Lower Lake, 
 chromite. 
 
 Los ANGELES Co.—Near Santa Anna River, anhydrite ; Williams 
 Pass, chalcedony ; Soledad mines, chalcopyrite, garnet, gypsum ; 
 Mountain Meadows, garnet, in copper ore. 
 
 Marreosa Co.—Chalcopyrite, itacolumyte ; Centreville, cinnabar ; 
 Pine Tree mine, tetrahedrite ; Burns Creek, limonite ; Geyer Gulch, 
 pyrophyllite ; La Victoria mine, azurite / near Coulterville, cinnabar, 
 gold. 
 
 Mono Co.—Partzite (stibiconite). 
 
 Monterey Co.—Alisal mine, arsenic ; near Paneches, chalcedony ; 
 New Idria mine, cinnabar ; near New Idria, chromite, zaratite, chrome 
 garnet ; near Pacheco’s Pass, stibnite. 
 
 Napa Co.—Chromite. 
 
 NEVADA Co.—Grass Valley, gold/ in quartz veins, with pyrite, 
 chalcopyrite, blende, arsenopyrite, galenite, quartz, biotite ; near 
 Truckee Pass, gypsum; Excelsior Mine, molybdenite, with gold; 
 Sweet Land, pyrolusite. 
 
 PLACER Co.—Miner’s Ravine, epidote /! with guariz, gold. 
 
 PLumas Co.—Genesee Valley, chalcopyrite ; Hope mines, bornite, 
 sulphur. 
 
 S,nTA BARBARA Co.—San Amedio Cation, stibnite, asphaltum, bitu- 
 men, maltha, petroleum, cinnabar, iodide of mercury ; Santa Clara 
 River, sulphur. ¢ 
 
 San BERNARDINO Co.—Colorado River, agate, trona ; Temescal 
 Mts., cassiterite; Russ District, galenite, cerussite ; Francis mine, 
 cerargyrite; Slate Range, thenardite, borax, common salt; San Ber- 
 nardino Mts., graphites. 
 
 Santa CLARA Co.—New Almaden, cinnabar, calcite, aragonite, ser- 
 pentine, chrysolite, quartz, aragotite ; North Almaden, chromite ; Mt. 
 Diabolo Range, magnesite, datolite, with vesuvianite and garnet. 
 
 Saw Drago Co,-—Carisso Creek, gypsum ; San Isabel, tourmaline, 
 orthoclase, garnet. 
 
 San Francisco Co.—Red Island, pyrolusite and manganese ores. 
 
 San Luis Opispo Co.—Asphaltum, cinnabar, native mercury, 
 chroniite. 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 367 
 
 Smasra Co.—Near Shasta City, hematite, in large masses. 
 
 SIERRA Co.—Forest City, gold, arsenopyrite, tellurides. 
 
 Siskiyou Co.--Surprise Valley, selenite, in large slabs. 
 
 Sonoma Co.—Actinolite, garnets, chromite, serpentine. 
 
 TULARE Co,—Near Visalia, magnesite, asphaltum. 
 
 TUOLUMNE Co.—Tourmaline, tremolite ; Sonora, graphite ; York 
 Tent, chromite ; Golden Rule mine, petzite, calaverite, altaite, hessite, 
 magnesite, tetrahedrite, gold ; Whiskey Hill, gold / 
 
 TRINITY Co.—Cassiterite, a single specimen found. 
 
 LOWER CALIFORNIA. 
 
 La Paz.—Cuproscheelite. Loretro.—Natrolite, siderite, selonite. 
 
 UPA: 
 
 BEAVER Co.—Bismuthinite, bismite, bismutite. 
 
 Tintic District.—At the Shoebridge mine, tho Dragon mine, and 
 the Mammoth vein, enargite with pyrite. 
 
 Box EvpER Co.—Empire mine, wulfenite/ 
 
 UtTau Co.—Ammonia alum. 
 
 In the Wahsatch and Oquirrh mountains there are extensive mines, 
 especially of ores of lead rich in silver. At the Emma mine occur 
 galenite, cervantite, cerussite, wulfenite, azurite, malachite, calamine, 
 anglesite, linarite, sphalerite, pyrite, argentite, stephanite, etc. At 
 the Lucky Boy mine, Butterfield Cafion, orpiment, realgar. 
 
 One hundred and twenty miles southwest of Salt Lake City, topaz 
 has been found in colorless crystals. At a silver mine, fibrous se- 
 piolite. ; 
 
 NEVADA. 
 
 CARSON VALLEY.--Chrysolite. 
 
 CHURCHILL Co.—Near Ragtown, gay-lussite, trona, common salt. 
 
 Comstock LoDE.—Gold, native silver, argentite, stephanite, polyba- 
 site, pyrargyrite, proustite, tetrahedrite, cerargyrite, pyrite, chalcopy- 
 rite, galenite, blende, pyromorphite, allemontite, arsenolite, quartz, 
 calcite, gypsum, cerussite, cuprite, wulfenite, amethyst, kiistelite. 
 
 ELKo Co.—Emma Mine, chrysocolla. . 
 
 ESMERALDA Co.—Alum, 12 m. north of Silver Creek; at Aurora, 
 fluorite, stibnite ; near Mono Lake, native copper and cuprite, obsi- 
 dian; Thiel Salt Marsh, ulexite, borax, common salt, thenardite ; 
 Columbus district, ulexite, thenardite, sulphur ; Walker Lake, gyp- 
 sum, hematite; Silver Peak, salt, saltpetre, sulphur, silver ores. 
 
 HumBouptr Districr.—Sheba mine, native silver, jamesonite, stib- 
 nite, tctrahedrite, proustite, blende, cerussite, calcite, bournonite, py- 
 rite, galenite, malachite, xanthocone (?), cuprite. 
 
 LANDER Co.—<Austin, polybasite, chalcopyrite, azurite. 
 
 Lincoun Co.—Rock salt, cerargyrite. 
 
 MammoriH Districr.—Orthoclase, turquoise, hiibnerite, scheelite. 
 
 Nyr Co.--Anglesite, stetefeldite, azurite, cerussite, silver ores, 
 cerargyrite. 5 
 
868 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 Reese River Disrrict.——Native silver, proustite, pyrargyrite, 
 stephanite, blende, polybasite, rhodochrosite, embolite, tctrahedrite ! 
 cerargyrite, embolite. % 
 
 San ANTONIA.—Belmont mine, stetefeldtite. 
 
 Srx-MiILE Cafton.—Selenite. 
 
 Ormspy Co.-—W. of Carson, epidote. 
 
 STroREY Co.—Alum, natrolite, scolecite. 
 
 Wuitr Pine Co.—Bberhardt mine, cerargyrite ; Paymaster mine, 
 freieslebenite. 
 
 ARIZONA. 
 
 To the south, south of Tucson, near the Mexican boundary, the re- 
 gion about Tubac Arivaca, the Santa Rita and the Patagonia Mts., 
 noted for silver mines, the ore in part argentiferous galenite ; about 
 Tucson, copper ores ; a little to the north, the Heintzelmann mine, 
 Stromeyerite, chalcocite, tetrahedrite, native silver, atacamite ; on 
 and near the Colorado River, in Yuma County, the Castle Dome, Eu- 
 reka and other mines, of gold, silver, and copper, argentiferous gale- 
 nite the prominent silver ore. In the Penal range, gold; on the San 
 Francisco River, native copper, covellite, chalcopyrite, malachite, azu- 
 rite ; at Bill Williams Fork, malachite, chrysocolla, atacamite, bro- 
 chantite ; Montgomery mine, Harsayampa district, tetradymite. 
 
 North of the Gila, just west of the boundary of New Mexico, chalco- 
 cite, cuprite, malachite. 
 
 OREGON AND WASHINGTON. 
 
 Gold is obtained from beach washings on the southern coast ; quartz 
 mines and placer mines in the Josephine district ; also on the Powder, 
 Burnt, and John Day's rivers, and other places in Hastern Oregon ; 
 platinum, iridosmine, laurite, on the Rogue River, at Port Orford, 
 and Cape Blanco. In Curry Co., priceite. 
 
 At Seattle, Washington T --Scheelite, tourmaline ; at Fidalgo, 
 realgar. 
 
 IDAHO, 
 
 In the Owyhee, Boise, and Flint districts, gold, also extensive silver 
 mines : Poor Man’s Lode, cerargyrite ! proustite, pyrargyrite ! native 
 silver, gold, pyromorphite, quartz, malachite, stephanite ; polybasite ; 
 on Jordan Creek, stream tin ; Rising Star mine, stephanite, argentite, 
 
 pyrargyrite ; Charity mine, Warren’s, scheelite, gold. 
 
 MONTANA. 
 
 Many mines of gold, etc., west of the Missouri River. HIGHLAND 
 Disrrict.—Tetradymite. SILVER STAR Dist.——Psittacinite. 
 
 In the Yellowstone Park, in Montana and Wyoming Territories.-— 
 Geyserite, amethyst ! chalcedony, quartz crystals, quartz on calcite, 
 etc, 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 369 
 
 COLORADO. 
 
 The principal gold mines of Colorado are in Boulder, Gilpin, Clear 
 Creek, and Jefferson Counties, on a line of country a few miles W. of 
 Denver, extending from Long’s Peak to Pike’s Peak. A large portion 
 of the gold is associated with veins of pyrite and chalcopyrite ; silver 
 and lead mines are at and near Georgetown, Clear Creek County, and 
 to the westward. in Summit County, on Snake and Swan rivers. 
 
 At the GEORGETOWN mines are found :—native silver, pyrargyrite, 
 argentite, tetrahedrite, pyromorphite, galenite, sphalerite, azurite, 
 aragonite, barite, fluorite, mica. 
 
 TRAIL CREEK.—Garnet, epidote, hornblende, chlorite ; at the Free- 
 land Lode, tetrahedrite, tennantite, anglesite, caledonite, cerussite, 
 tenorite, siderite, azurite, minium ; at the Champion Lode, tenorite, 
 azurite, chrysocolla, malachite ; at the Gold Belt Lode, vivianite ; at 
 the Kelly Lode, tenorite ; at the Coyote Lode, malachite, cyano- 
 trichite. 
 
 Near Buack HawxK.—At Willis Gulch, enargite, fluorite, pyrite; at 
 the Gilpin County Lode, cerargyrite ; on Gregory Hill, feldspar ; 
 North Clear Creek, lievrite.—Ga/ientte / 
 
 BEAR CREEK.— Fluorite, beryl ; near the Malachite Lode, malachite, 
 cuprite, vesuvianite, topazolite ; Liberty Lode, chalcocite. 
 
 SNAKE RiveR.—Penn District, embolite ; at several lodes, pyrar- 
 gyrite, native silver, azurite. 
 
 RussELL District.—Delaware Lode, chalcopyrite, crystallized gal- 
 enite.—Epidote, pyrite. 
 
 VirGiniA CaNON.—Epidote, fluorite ; at the Crystal Lode, native 
 silver, spinel. 
 
 Sugar Loar Disrrictr.—Chalcocite, pyrrhotite, garnet (mangane- 
 sian). 
 
 CENTRAL CiTy.—Garnet, tenorite; at Leavitt Lode, molybdenite ; 
 on Gunnell Hill, magnetite ; at the Pleasantview mine, cerussite. 
 
 GOLDEN City.—Aragonite; on Table Mountain, leucite in amygda- 
 loid. 
 
 BERGEN’S RANCHE.—Garnet, actinolite, calcite. 
 
 BOULDER Co.—Red Cloud Mine: Native tellurium, altaite, hessite 
 (petzite), sylvanite, calaverite, schirmerite. Keystone Mine: Colora- 
 doite, magnolite, ferotellurite, tellurite, roscoelite? also part of these 
 at Smuggler mine and Mountain Lion mine. Grand View mine: syl- 
 vanite, etc. 
 
 Lakz Cry, at the Hotchkiss Lode.—Petzite, calaverite (?), etc. 
 
 LAKE Co., Golden Queen mine.—Scheelite, gold. 
 
 Pikn’s Prag, on Elk Creek.—Amazon-stone ! ! smoky quartz! aven- 
 turine feldspar, amethyst, albite, fluorite, hematite, anhydrite (rare), 
 columbite. 
 
 San Juan Disrriot.—Gold, sphalerite, pyrite, galenite, chalcocite, 
 covellite, chalcopyrite. 
 
 re 
 
 CANADA EAST. 
 
 ABERCROMBIE.—Labradorite. 
 AUBERT.—Gold, iridosmine, platinum. 
 Balk 8. Pavuu.—WNMenaccanite/ apatite, allanite, rutile. ap 
 
370 SUPPLEMENT TO DESCRIPTIONS OF SPECIES, 
 
 Botron.—Chromite, magnesite, serpentine, picrolite, steatite, bitter 
 spar, wad, rutile. 
 BoOUCHERVILLE.—Augite in trap. 
 BromE.—Magnetite, chalcopyrite, sphene, menaccanite, phyllite, 
 sodalite, cancrinite, galenite, chloritoid, rutile. 
 BROUGHTON.—Serpentine, steatite. 
 CHAMBLY.—Analcite, chabazite and calcite in trachyte, menaccanite, 
 CHatEau RicnHER.—Labradorite, hypersthene, andesite. 
 DAILLEBOUT.—Blue spinel with clintonite. 
 GRENVILLE.—Wollastonite, sphene, muscovite, vesuvianite, calcite, 
 pyroxene, serpentine, steatite (rensselaerite), chondrodite, garnet (cin- 
 namon-stone), zircon, graphite, scapolite. 
 Firzroy.—Graphite. 
 Ham.—Chromite in serpentine, diallage, antimony / senarmontite / 
 hermesite, valentinite, stibnite. 
 fluNTERSTOWN.—Scapolite, sphene, vesuvianite, garnet, brown tour- 
 maline ! 
 INVERNESS.—Bornite, chalcocite, pyrite. 
 LAKE ST. Francis.—Andalusite in mica slate. 
 LEEDS.—Dolomite, chalcopyrite, gold, chloritoid, chalcocite, bornite, 
 yrite, steatite. 
 MILLE Istus.—Labradorite ! menaccanite, hypersthene, andesite, 
 Zircon. 
 MonTREAL.—Calcite, augite, sphene in trap, chrysolite, natrolite, 
 dawsonite. 
 Morin.—Sphene, apatite, labradorite. 
 ORFORD.— White garnet, chrome garnet, millerite, serpentine. 
 Orrawa.—Pyrowene. 
 PORTAGE DE Fort.—Rensselaerite. 
 | Porron.—Chromite, steatite, serpentine, amianthus. 
 | RovucEMonT.—Augite in trap. 
 ' Op, ARMAND, —Micaceous iron ore with quartz, epidote. 
 Sr. FRANCOIS Brauce.—Gold, platinum, iridosmine, menaccanite, 
 magnetite, serpentine, chromite, soapstone, barite. 
 Sr, JEROME.—Sphene, apatite, chondrodite, phlogopite, tourmaline, 
 zircon, garnet, molybdenite, pyrrhotite, wollastonite, labradorite. 
 Sr, NoRBERT.—Amethyst in greenstone. 
 SHERBROOK.—At Suffield mine, albite ! native silver, argentite, 
 chalcopyrite, blende. 
 SourH-Crospy.—Chondrodite. 
 STUKELEY.—Serpentine, verd-antique ! schiller spar. 
 Surron.—WMagnetite, in fine crystals, hematite, rutile, dolomite, 
 magnesite, chromiferous talc, bitter spar, steatite. 
 Upton.—Chalcopyrite, malachite, calcite. 
 VAUDREUIL.—Limonite, vivianite. 
 Yamaska.—Sphene in trap. 
 
 CANADA WEST. 
 
 ARNPRIOR. —Calcite. 
 BALSAM LAKE,—Molybdenite, scapolite, quartz, pyroxene, pyrite. 
 Batruurst.—Barite, black tourmaline, perthite (orthoclase), peristerite 
 
 (albite), bytowntte, pyroxene, wilsonite, scapolite, apatite, titanite. 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 371 
 
 BRANTFORD.—Sulphuric acid spring (4:2 parts of pure sulphuric 
 acid in 1,000). 
 
 BROCKVILLE. —Pyrite. 
 
 BROME.—Magnetite. 
 
 BruckE Minkgs on Lake Huron.—Calcite, dolomite, quartz, chalcopy- 
 rite, chalcocite. 
 
 BuRGEss.—Pyrovrene, albite, mica, corundum, sphene, chalcopyrite, 
 apatite, black spinel / spodumene (in a boulder), serpentine, biotite. 
 
 Bytown.—Calcite, bytownite, chondrodite, spinel. 
 
 CAPE IPPERWASH, Lake Huron.—Oxalite in shales. 
 
 CHAUDIERE VALLEY.—Gold, sphalerite, pyrite, pyrrhotite, galenite. 
 
 CLARENDON.— Vesuvianite, tourmaline. 
 
 DALHOovusI£.—Hornblende, dolomite. 
 
 DrumMMonD.—Labradorite. 
 
 ELIZABETHTOWN.—Pyrrhotite, pyrite, calcite, magnetite, talc, phlo- 
 gopite, siderite, apatite, cacoxenite. 
 
 ELMsLEY.—Pyroxene, sphene, feldspar, tourmaline, apatite, biotite, 
 zircon, red spinel, chondrodite. 
 
 Fitzroy.—Amber, brown tourmaline, in quartz. 
 
 G@TINEAU RIVER, Blasdell’s Mills.—Calcite, apatite, tourmaline, 
 hornblende, pyroxene. 
 
 GRAND CALUMET IsLAND.—Apatite phlogopite! pyroxene! horn- 
 blende, sphene, vesuvianite / / serpentine, tremolite, scapolite, brown 
 and black tourmaline! pyrite, loganite. 
 
 Hic FALLs oF THE MADAWASKA.—Pyroxene / hornblende. 
 
 Huiu.—Magnetite, garnet, graphite, 
 
 HUNTINGTON. —Calcite / 
 
 INNISKILLEN. —Petroleum. 
 
 Kin@ston.—Celestite. 
 
 Lac DES CHATs, Island Portage.—Brown tourmaline! pyrite, cal- 
 cite, quartz. 
 
 LANARK.—Raphilite (hornblende), serpentine, asbestus, perthite 
 (aventurine feldspar), peristerite. 
 
 LANSDOWNE. —Barite/ vein 27 in. wide, and fine crystals, rens- 
 selaerite, sphalerite, wilsonite, labradorite. 
 
 Mapoc.—Magnetite. 
 
 MARMORA.—Magnetite, chalcolite, serpentine, garnet, epsomite, 
 specular iron, steatite. 
 
 McNas.—Hematite, barite. 
 
 MICHIPICOTON IsLAND, Lake Superior.—Domeykite, nicolite, gen- 
 thite, chalcopyrite, native copper, native silver, chalcocite, galenite, 
 amethyst, calcite, stilbite, analcite. At Maimanse Bay: Coracite, 
 chalcocite, chalcopyrite, native copper. 
 
 NEwsorovGH.—Chondrodite, graphite. 
 
 PAKENHAM.—Hornblende. 
 
 PERTH.—Apatite in large beds, phlogopite. 
 
 St. ADELE.—Chondrodite in limestone. 
 
 St. Ignace IsLAnvD.--Calcite, native copper. 
 
 SruvErR Ip., Lake Superior.—-Argentite, native silver, galenite, nic- 
 colite, chalcocite, malachite. 
 
 SYDENHAM.—Celestite. 
 
 TERRACE COVE, Lake Superior.—Molybdenite. 
 
 WALLACE Mine, Lake Huron.—Hematite, nickel ore, nickel vitriol, 
 chalcopyrite. 
 
S72 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 NEW BRUNSWICK. 
 
 Apert Co.—Hopewell, gypsum ; Albert mines, coal (albertite) ; 
 Shepody Mountain, alunite in clay, calcite, pyrite, manganite, psilo- 
 melane, pyrolusite. 
 
 CARLETON Co. — Woodstock, chalcopyrite, hematite, limonite, 
 wad. 
 
 CHARLOTTE Co.--Campobello, at Welchpool, blende, chalcopyrite, 
 bornite, galenite, pyrite ; at head of Harbor de Lute, galenite ; Deer 
 Island, on west side, calcite, magnetite, quartz crystals ; Digdighash 
 River on west side of entrance, caleite/ (in conglomerate), chalcedony ; 
 at Rolling Dam, graphite ; Grandmanan, between Northern Head and 
 Dark Harbor, agate, amethyst, apophyllite, calcite, hematite, heulan- 
 dite, jasper, magnetite, natrolite, stilbite; at Whale Cove, calcite ! 
 heulandite, laumontite, stilbite, semi-opal ! ; Wagaguadavic River, at 
 entrance, azurite, chalcopyrite in veins, malachite. 
 
 GLOUCESTER Co.—Tete-a-Gouche River, eight miles from Bathurst, 
 chalcopyrite (mined), oade of manganese ! | formerly mined. 
 
 Krincs Co.—Sussex, near Cloat’s mills, on road to Belleisle, argen- 
 tiferous galenite ; one mile north of Baxter’s Inn, specular tron in 
 crystals, limonite ; on Capt. McCready’s farm, selenite! / 
 
 RestigoucnE Co.—Belledune Point, calcite! serpentine, verd-an- 
 tique ; Dalhousie, agate, carnelian. 
 
 Sp Joun Co.—Black River, on coast, calcite, chlorite, chalcopyrite, 
 hematite! Brandy Brook, epidote, hornblende, quartz crystals ; Carle- 
 ton, near Falls, calcite ; Chance Harbor, calcite in quartz veins, chlo- 
 rite in argillaceous and talcose slate ; Little Dipper Harbor, on west 
 side, in greenstone, amethyst, barite, quartz crystals ; Moosepath, 
 feldspar, hornblende, muscovite, black tourmaline; Musquash, on 
 east side harbor, copperas, graphite, pyrite ; at Shannon’s, chrysolite, 
 serpentine ; east side of Musquash, quartz erystals ! ; Portland at the 
 Falls, graphite ; at Fort Howe Hill, calcite, graphite ; Crow’s Nest, 
 asbestus, chrysolite, magnetite, serpentine, steatite ; Lily Lake, white 
 augite? chrysolite, graphite, serpentine, steatite talc; How’s Road, 
 two miles out, epidote (in syenite), steatite in limestone, tremolite ; 
 Drury’s Cove, graphite, pyrite, pyrallolite ? indurated talc ; Quaco, at 
 Lighthouse Point, large bed oxide of manganese ; Sheldon’s Point, 
 actinolite, asbestus, calcite, epidote, malachite, specular iron ; Cape 
 Spenser, asbestus, calcite, chlorite, specular iron (in crystals) ; West- 
 beach, at east end on Evans’s Farm, chlorite, talc, quartz crystals ; 
 half a mile west, chlorite, chalcopyrite, magnesite (vein), magnetite ; 
 Point Wolf and Salmon River, asbestus, chlorite, chrysocolla, chalco- 
 pyrite, bornite, pyrite. 
 
 Vicroria Co.—Tabique River, agate, carnelian, jasper ; at mouth, 
 south side, galenite ; at mouth of Wapskanegan, gypsum, salt spring; 
 three miles above, stalactites (abundant) ; Quisabis River, blue phos- 
 phate of iron, in clay. ; 
 
 WESTMORELAND Co.—Bellevue, pyrite; Dorchester, on Taylor’s 
 Farm, cannel coal ; clay ironstone ; on Ayres’s Farm, asphaltum, petro- 
 leum spring ; Grandlance, apatite, selenite (in large crystals) ; Mem- 
 ramcook, coal (albertite) ; Shediac, four miles up Scadoue River, coal. 
 
 Yorx Co. — Near Fredericton, stibnite, jamesonite, berthierite ; 
 Pokiock River, stibnite, tin pyrites? in granite (rare). , 
 
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 3'73 
 
 NOVA SCOTIA. 
 
 ANNAPOLIS Co.—Chute’s Cove, apophyllite, natrolite ; Gates’s Moun- 
 tain, analcite, magnetite, mesolite / natrolite, stilbite ; Martial’s Cove, 
 analcite/ chabazite, heulandite ; Moose River, beds of magnetite ; 
 Nictau River, at the Falls, bed of hematite; Paradise River, black 
 tourmaline, smoky quartz //; Port George, fardelite, laumontite, rae- 
 solite, stilbite ; east of Port George, on coast, apophyllite containing 
 gyrolite; Peter's Point, west side of Stonock’s Brook, apophyllite / 
 calcite, heulandite, /awmontite / (abundant), native copper, stilbite St, 
 Croix’s Cove, chabazite, heulandite. 
 
 COLCHESTER Co.—Five Islands, Hast River, barite/ calcite, dolo- 
 mite (ankerite), hematite, chalcopyrite; Indian Point, malachite, 
 magnetite, red copper, tetrahedrite ; Pinnacle Islands, analcite, calcite, 
 chabazite / natrolite, siliceous sinter ; Londonderry, on branch of Great 
 Village River, barite, ankerite, hematite, limonite, magnetite ; Cook’s 
 Brook, ankerite, hematite ; Martin’s Brook, hematite, limonite; at 
 Folly River, below Falls, ankerite, pyrite ; on high land, east of river, 
 ankerite, hematite, limonite ; on Archibald’s land, ankerite, barite, 
 hematite; Salmon River, south branch of, chalcopyrite, hematite ; 
 Shubenacadie River, anhydrite, calcite, barite, hematite, oxide of 
 manganese ; at the Canal, pyrite ; Stewiacke River, barite (in lime- 
 stone). 
 
 CUMBERLAND Co.—Cape Chiegnecto, barite ; Cape d’Or, analcite, 
 apophyllite/! chabazite, fardelite, laumontite, mesolite, malachite, 
 natrolite, native copper, obsidian, red copper (rare), vivianite (rare) ; 
 Horse Shoe Cove, east side of Cape d’Or, analcite, calcite, stilbite ; 
 Isle Haute, south side, analcite, apophyllite!! calcite, heulandite /! 
 natrolite, mesolite, stilbite/; Joggins, coal, hematite, limonite ; mala- 
 chite and tetrahedrite at Seaman’s Brook ; Partridge Island, analcite, 
 apophyllite ! (rare), amethyst ! agate, apatite (rare), calcite //! chabazite 
 (acadialite), chalcedony, cat’s eye (rare), gypsum, hematite, Aeulan- 
 dite! magnetite, stilbite//; Swan’s Creek, west side, near the Point, 
 calcite, gypsum, heulandite, pyrite; east side, at Wasson’s Bluff and 
 vicinity, analcite!! apophyllite ! (rare), calcite, chabazite!! (acadialite), 
 gypsum, heulandite!! natrolite!/ siliceous sinter ; Two Islands, moss 
 agate, analcite, calcite, chabazite, hewlandite ; McKay’s Head, anal- 
 cite, calcite, heulandite, siliceous sinter / 
 
 Diesy Co. — Briar Island, native copper, in trap; Digby Neck, 
 Sandy Cove and vicinity, agute, amethyst, calcite, chabazite, hematite! 
 laumontite (abundant), magnetite, stibite, quartz crystals ; Gulliver’s 
 Hole, magnetite, stilbite! ; Mink Cove, amethyst, chabazite! quartz 
 crystals ; Nichols Mountain, south side, amethyst, magnetite!; Wil- 
 liams Brook, near source, chabazite (green), heulandite, stilbite, quartz 
 crystal. 
 
 GuyYsBORO’ Co.—Cape Canseau, andalusite. 
 
 HALiIrax Co.—Gay’s River, galenite in limestone; southwest of 
 Halifax, garnet, staurolite, tourmaline; Tangier, gold/ in quartz 
 veins in clay slate, associated with auriferous pyrite, galenite, hema- 
 tite, arsenopyrite, and magnetite ; gold at Country Harbor, Fort Clar- 
 ence, Isaac’s Harbor, Indian Harbor, Laidlow’s Farm, Lawrencetown, 
 Sherbrooke, Salmon River, Wine Cove, and other places. 
 
 Hants Co.—Cheverie, oxide of manganese (in limestone) ; Petite 
 
374 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 ay 
 
 River, gypsum, oxide of manganese ; Windsor, calcite, cryptomorphite 
 (baronatrocalcite), howlite, glauber salt. The last three minerals are 
 found in beds of gypsum. 
 
 Kines Co.—Black Rock, centrallassite, cerinite ; cyanolite ; a few 
 miles east of Black Rock, prehnite ? stilbite/; Cape Blomidon, on the 
 coast between the cape and Cape Split, the following minerals occur 
 in many places (some of the best localities are nearly opposite Cape 
 Sharp): analcite/! agate, amethyst ! apophyllite ! calcite, chalcedony, 
 chabazite, gmelinite (lederite), hematite, heulandite ! laumontite, mag~- 
 netite, malachite, mesolite, native copper (rare), natrolite / psilomelane, 
 stilbite! thomsonite, fardelite, quartz ; North Mountains, amethyst, 
 ploodstone (rare), ferruginous quartz, mesolite (in soil); Long Point, 
 five miles west of Black Rock, heulandite, laumontite/! stilbite!!; 
 Morden, apophyllite, mordenite ; Scott’s Bay, agate, amethyst, chalce- 
 dony, mesolite, natrolite ; Woodworth’s Cove, a few miles west of 
 Scott’s Bay, agate! chalcedony ! jasper. 
 
 LUNENBERG Co.—Chester, Gold River, gold in quartz, pyrite, mis- 
 pickel ; Cape la Have, pyrite; The «‘Qvens,” gold, pyrite, arseno- 
 pyrite ; Petite River, gold in slate. 
 
 Prorou Co.—Pictou, jet, oxide of manganese, limonite ; at Roder’s 
 Hill, six miles west of Pictou, barite ; on Carribou River, gray copper 
 and malachite in lignite ; at Albion mines, coal, limonite ; East River, 
 limonite. 
 
 QUEEN’S Co.— Westfield, gold in quartz, pyrite, arsenopyrite ; Five 
 Rivers, near Big Fall. gold in quartz, pyrite, arsenopyrite, limonite. 
 
 Ricumonp Co.-—West of Plaister Cove, barite and calcite in sand- 
 stone ; nearer the Cove, calcite, fluorite (blue), siderite. 
 
 SHELBURNE Co.—Shelburne, neat mouth of harbor, garnets (in 
 gneiss) ; near the town, rose quartz ; at J ordan and Sable River, stau- 
 rolite (abundant), schiller spar. 
 
 SypnEY Co.—Hills east of Lochaber Lake, pyrite, chalcopyrite, side- 
 rite, hematite ; Morristown, epidote in trap, gypsum. 
 
 YarmoutH Co.—Cream Pot, above Cranberry Hill, gold in quartz, 
 pyrite ; Cat Rock, Fouchu Point, asbestus, calcite. 
 
 NEWFOUNDLAND. 
 
 Anrvony’s IsuANnD.—Pyrite. 
 
 CATALINA HaRBorR.——On the shore, pyrite ! 
 
 CHALKY Hiu.—Feldspar: 
 
 CopPER ISLAND, one of the Wadham group.—Chalcopyrite. 
 
 CoNCEPTION Bay.—On the shore south of Brigus, bornite and gray 
 copper in trap. 
 
 Bay oF IsLANDS.—Southern shore, pyrite in slate. 
 
 Lawn.—Galenite, cerargyrite, proustite, argentite. 
 
 PLACENTIA BAy.—At La Manche, two miles eastward of Little 
 Southern Harbor, galenite /; on the opposite side of the isthmus from 
 Placentia Bay, barite in a large vein, occasionally accompanied by 
 chalcopyrite. 
 
 SHoaL Bay.—South of St. J ohn’s, chalcopyrite. 
 
 Trrity Bay.— Western extremity, barite. 
 
 HARBOR GREAT ST. LAWRENCE.— West side, fluorite, galenite. 
 
ish) 
 ~ 
 Cr 
 
 FOREIGN MINING REGIONS. 
 
 BRITISH COLUMBIA. 
 
 CARIBOO DistRict.—Native gold, galena. 
 
 ON FRAZER RtvER.—Gold, argentiferous tetrahedrite, cerargyrite, 
 cinnabar. : 
 
 OmINIcA Distriot.—Native gold, argentiferous galenite, native 
 silver, silver-amalgam. 
 
 Hower’s Sounp.—Bornite, molybdenite, mica. 
 
 TEXADA Ip.—Magnetite. 
 
 Il. BRIEF NOTICE OF FOREIGN MINING 
 REGIONS. 
 
 THE geographical positions of the different mining regions are learned 
 with difficulty from the scattered notices in the course of a minera- 
 logical treatise. A general review of the more important is therefore 
 here given, to be used in connection with a good map. 
 
 A course across Europe, from southeast to northwest, passes over a 
 large part of the mining regions, and it will be found most convenient 
 to the memory to mention them in this order, commencing with the 
 borders of Turkey. 
 
 1. The mines of the Bannat in Southern Hungary, near the borders 
 of Turkey (about latitude 45°), situated principally at Orawitza, Sasz- 
 ka, Dognaszka, and Moldawa: argentiferous copper ores, chalcocite, 
 malachite, copper pyrites, cuprite, galenite, ores of zinc, cobalt, native 
 gold ; yielding silver, gold, copper, and lead ; rock: syenyte, and gran- 
 ular limestone. 
 
 2. The mines of Western Transylvania, about latitude 46°, situated 
 between the rivers Maros and Aranyos, at Nagyag, Offenbanya, Sa- 
 lathna, and Voriéspatak : native gold, telluric gold, telluric silver, 
 white tellurium, with galenite, blende, orpiment, reaigar, stibnite, tet- 
 rahedrite, rhodochrosite or carbonate of manganese, manganblende ; 
 especially valuable in gold and silver. 
 
 3. In the mountain range, bounding Transylvania on the north, 
 about latitude 47° 40’, at Nagybanya, Felsobanya, and Kapnik : na- 
 tive gold, red silver, argentiferous tetrahedrite, chalcopyrite or pyri- 
 tous copper, blende, realgar, stibnite or gray antimony ; rock. por- 
 
 phyry. 
 
 4, Inthe Kénigsberg Mountains, Northern Hungary, about latitude 
 48° 45', at Schemnitz and Kremnitz : argentiferous galenite, and chal- 
 copyrite, native gold, red silver ore, stibnite, some cobalt ores and bis- 
 muth, arsenopyrite or mispickel ; particularly valuable for gold, sil- 
 ver and antimony ; rock ; diorite and porphyry. 
 
 5. To the east of the Kénigsberg Mountains, at Schmolnitz and Retz- 
 banya: chalcopyrite, tetrahedrite, blende, stibnite ; particularly valu- 
 able for copper ; rock: clay slate. . 
 
 6. Illyria, west of Hungary, at Bleiberg and Raibel (in Carinthia) : 
 argentiferous galenite, calamine, with some chalcopyrite and other 
 ores, affording silver and zinc abundantly ; rock: mountain limestone, 
 —Also at Idria, native mercury and cinnabar, in argillaceous schist. 
 
376 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 ”. In Western Styria, at Schladming: arsenical nickel, copper 
 nickel, native arsenic, arsenical iron, largely worked for nickel ; rock : 
 argillaceousslate. Illyria and Styria are noted also for their iron ores, 
 especially siderite or spathic iron. 
 
 8, In the Tyrol, at Zell: argentiferous copper and iroil ores, aurife- 
 rous pyrite, native gold; rock: argillaceous slate. 
 
 9, In the Erzgebirge separating Bohemia from Saxony, and consist- 
 ing principally of gneiss : 
 
 A. Bohemian or southern slope, at J oachimsthal, Mies, Schlacken- 
 wald, Zinnwald, Bleistadt, Przibram, Katherinenberg: tin ores, ar- 
 gentiferous galenite (worked principally for silver), arsenical cobalt 
 ores, copper nickel ; affording tin, silver, cobalt, nickel and arsenic. 
 
 B. Saxon or northern slope, at Altenberg, Geyer, Marienberg, Anna- 
 berg, Schneeberg, Ehrenfriedersdorf, Johanngeorgenstadt, Freiberg : 
 argentiferous galenite (worked only for silver), tin ore, various cobalt 
 and nickel ores, vitreous and pyritous copper ; affording silver, tin, 
 cobalt, nickel, bismuth, and copper. 
 
 10. In Silesia, in the Riesengebirge, an eastern extension of the Erz- 
 gebirge, at Kupferberg, Jauer, Reichenstein: ores of copper, cobalt, 
 affording copper, cobalt, arsenic and sulphur. 
 
 11. In Silesia, in the low country east of the Riesengebirge, near 
 the boundary of Poland, at Tarnowitz : calamine, smithsonite, blende, 
 argentiferous galenite ; affording zinc, silver and lead ; rock; moun- 
 tain limestone. 
 
 42. Northwest of Saxony, near latitude 51° 30’, at Fisleben, Gerlstadt. 
 Sangerhausen, and Mansfeld: tetrahedrite, somewhat argentiferous, 
 bornite or variegated copper ore, affording copper ; rock : a marly bi- 
 tuminous schist (kupferschiefer) more recent than the Carboniferous 
 strata. 
 
 13. In the Harzgebirge (Hartz Mountains), north of west from His- 
 leben, about latitude 51° 50’, at Clausthal, Zellerfeld, Lauthenthal, 
 Wildemann, Grund, Andreasberg, Goslar, Lauterberg : chalcocite or 
 vitreous copper, tetrahedrite, chalcopyrite, cobalt ores, copper nickel, 
 ruby silver ore, argentiferous galenite, blende, antimony ores ; afford- 
 ing silver, lead, copper, and some gold. 
 
 14. In Hesse-Cassel, to the southwest of the Hartz, at Riechelsdorf : 
 arsenical cobalt, arsenical nickel, nickel ochre, native bismuth, bis- 
 muthinite, galenite, affording cobalt ; rock: red sandstone. Also at 
 Bieber, cobalt ores in mica slate. 
 
 15. In the Bavarian or Upper Rhine (Palatinate), near latitude 49° 
 45’, at Landsberg near Moschel, Wolfstein, and Morsfeld : cinnabar, 
 native mercury, amalgam, horn quicksilver, pyrite, some tetrahedrite, 
 and chalcopyrite ; rocks :; coal formation. 
 
 16. Province of the Lower Rhine, at Altenberg, near Aix la Chapelle 
 (or Aachen): calamine, smithsonite, galenite, affording zinc; rock 2 
 limestone. The same just south in Netherlands, at Limburg, and also 
 to the west at Vedrin, near Namur. 
 
 17. There are also copper mines at Saalfeld, west of Saxony, in 
 Saxon-Meiningen, in Southern Westphalia near Siegen, in Nassau at 
 Dillenberg, and elsewhere. 
 
 18. In Switzerland, at Canton du Valais: argentiferous galenite, and 
 valuable nickel and cobalt ores. 
 
 19. The range of the Vosges parallel with the Rhine, about 8t. 
 
FOREIGN MINING REGIONS., one 
 
 Marie-aux-Mines: argentiferous galenite (airording 1-1000 of silver), 
 with pyromorphites, tetrahedrite, antimonial sulphuret of silver, na-. 
 tive silver, arsenical cobalt, native arsenic, and pyrite, occasionally 
 auriferous ; affording silver and lead ; rocks: argillaceous schist, sye- 
 nyte, and porphyry. 
 
 20. In France there are also the mining districts of the Alps, Au- 
 vergne or the Plateau of Central France, Brittany, and the Pyrenees, 
 but none are very productive, except in irou ores. Brittany resembles 
 Cornwall, and formerly yielded some tin and copper. The valley of 
 Oisans in the Alps, at Allemont, contains argentiferous galenite, arseni- 
 cal cobalt and nickel, gray copper, native mercury, and other ores, in 
 talcose, micaceous, and syenytic schists, but they are not now explored. 
 The region of Central France is worked at this time only at Pont- 
 Gibaud, in the department of Puy-de-Dome, and at Vialas and Ville- 
 fort in the Gard. The former is a region of schistose and granite 
 rocks, intersected by porphyry, affording some copper, antimony, lead, 
 and silver ; the latter of gneiss, affording lead and silver, from argen- 
 tiferous galena. The French Pyrenees are worked at the present time 
 only for iron. 
 
 21. In England there are two great metalliferous districts : 
 
 A. On the southwest, in Cornwall, and the adjoining county of De- 
 vonshire : pyritous copper and various other copper ores, tin ores, 
 galenite, with some bismuth, cobalt, nickel and antimony ores ; afford- 
 ing principally copper, tin, and lead ; rocks : granite, gneiss, micaceous 
 and argillaceous schist, elvanyte. 
 
 B. On the north, in Cumberland, the adjoining paris of Durham, 
 with Yorkshire and Derbyshire, just south : galenite, and other lead 
 ores, blende, copper ores, calamine and smithsonite (the zinc ores es- 
 pecially at Alstonmoor in Cumberland, and Castleton and Matlock, in 
 Derbyshire), affording some zinc, and three-fifths of the lead of Great 
 Britain, and some copper ; rock: Carboniferous limestone. 
 
 C. There is also a vein of calamine, blende, and galenite, in the 
 same limestone at Holywell, in Flintshire, on the north of Wales ; 
 another of calamine at Mendip Hills, in Southern England, south of 
 the Bristol Channel, in Somersetshire, occurring in magnesian lime. 
 stone ; mines of copper on the Isle of Anglesey, in North Wales, in 
 Westmoreland and the adjacent parts of Cumberland and Lancashire, 
 in the southwest of Scotland, the Isle of Man, and at Ecton in Stafford- 
 shire, &c. 
 
 22. In Spain there are mines— 
 
 A. On the south, in the mountains near the Mediterranean coast, 
 in New Grenada, and east to Carthagena, in Murcia; also in New 
 Grenada, in the Sierra Nevada, or the mountains of Alpujarras, the 
 Sierra Almagrera, the Sierra de Gador, just back of Almeria, and at 
 Almazarron near Carthagena: galenite, which is argentiferous at the 
 Sierra Almagrera and at Almazarron,. affording full 1 per cent. of 
 silver ; rock: limestone, associated with schist and crystalline rocks. 
 
 B. The vicinity of the range of mountains running westward from 
 Alcaraz (to the district of La Mancha), to Portugal. 1. On the south, 
 near the centre of the province of Jaen, at Linares, latitude 88° 5’, 
 longitude 3° 40': galenite, cerussite, cuprite, malachite, in granite and 
 schists; affording lead and copper. 2. In La Mancha, at Alcaraz, 
 northeast of Linares, latitude 388° 45’; calamine affording abundantly 
 
378 SUPPLEMENT TO DESCRIPTIONS OF SPECIES. 
 
 zinc. 38. In the west extremity of La Mancha, near latitude 88° 38’, 
 at Almaden: cinnabar, native mercury, pyrite, in clay slate. 4, South- 
 west of Almaden, in Southern Estremadura, and Northwestern Seville : 
 tetrahedrite ; at Guadalcanal, Cazalla, Rio Tinto : chalcanthite or cop- 
 per vitriol, malachite, with some red silver ore, and native silver, in 
 schists or limestones. 
 
 There are also mines of lead and copper at Falsete in Catalonia ; in 
 Galicia, a little tin ore ; in the Asturias at Cabrales, copper ores. 
 
 93. In Sweden :—1. At Fahlun, in Dalecarlia : chalcopyrite, bornite ; 
 rock, syenyte and schists. At Finbo and Broddbo : tantalum ores, tin 
 ore. At Sala: argentiferous galenite, affording lead and silver ; rock, 
 crystalline limestone. At Vena (or Wehna) and at Tunaberg : arseni- 
 cal cobalt, erythrite ; rock, mica slate and gneiss. At Dannemora and 
 elsewhere : magnetic iron ore or magnetite. 
 
 94, In Norway, at Kongsberg : argentite or vitreous silver, native 
 silver, horn silver, native gold, galenite, native arsenic, blende ; rock, 
 mica slate. At Modum and Skutterud: cobalt ores, native silver ; 
 rock, mica slate. At Arendal, magnetic iron ore. — 
 
 95. In Russia:—In the Urals (mostly on the Asiatic side), at 
 Ekatherinenberg, Beresof, Nischne Tagilsk, etc. : native gold, plati- 
 num, iridium, native copper, cuprite, malachite. 2. The Altai 
 (Southern Siberia), at Kolyvan and Zmeof : native gold, native silver, 
 argentiferous galena, cerussite, native copper, oxides of copper, mala- 
 chite, chalcopyrite; rocks, metamorphic veds and porphyry. 3. In the 
 Daouria Mountains, east of Lake Baikal, at Nertchinsk : argentifer- 
 ous galenite, cerussite, mimetite, gray antimony, arsenopyrite, cala- 
 mine, cinnabar ; rocks, compact limestone and schists. 
 
 96. In Australia :—In Southern Queensland, and the northern part 
 of New South Wales, or the New England district : tin ore or cassi- 
 terite abundant, with also native gold. In New South Wales, along 
 the Blue Mountains and the continuation of the range parallel with 
 the coast north and south, in the Bathurst, Mudgee, Lachlan and other 
 districts: native gold, chalcopyrite, some cinnabar. In Victoria: na- 
 tive gold. In South Australia, especially at the Burra, Wallaroo, and 
 Moonta mines : copper ores. 
 
 Other foreign mining regions are the copper mines of Cuba, and 
 South America; the silver mines of Chili, Bolivia, Peru in South 
 America, and of Mexico; the gold mines of South America, especially 
 those of Brazil, South Africa, and of the Philippines, Borneo, New 
 Guinea, New Caledonia, and New Zealand in Australasia ; the quick- 
 silver mines of Huanca Velica, Peru, and those of China ; the tin 
 mines of Malacca (principally on the island of Junk-Ceylon), and of 
 the island of Banco between Borneo and Sumatra; of zinc, in China ; 
 of platinum, in Brazil, Colombia, St. Domingo, and Borneo; of palla- 
 dium, in Brazil ; of arsenic in Khoordistan, Turkey in Asia, and also in 
 
 China ; of nickel, in New Caledonia. 
 
DETERMINATION OF MINERALS. $79 
 
 IV. DETERMINATION OF MINERALS. 
 
 . iy the determination of minerals, no one order in the 
 succession in which characters should be examined answers 
 for all minerals, or even for all of the same section of species. 
 , A. For species having a metallic lustre : 
 
 | Color will be first noted ; and then streak—that is, the 
 color of the mineral on a surface scratched or abraded by a 
 fine file, or when very finely powdered, and the dustre of the 
 powder or abraded surface, whether metallic like the min- 
 eral or unmetallic. Hardness should be ascertained when 
 obtaining the streak. 
 
 Blowpipe and chemical characters are of the highest value, 
 giving generally the most certain results. 
 
 Specific gravity is especially distinctive with species hav- 
 ing a metallic lustre, since the differences in density among 
 such species are usually large.* 
 
 Crystalline form and cleavage are of first importance, 
 whenever the specimen allows of their determination. 
 
 B. For species without metallic lustre : 
 
 Streak is sometimes of importance, especially among spe- 
 cies in which it is highly colored. 
 
 Color is generally of little value owing to the variations 
 that frequently come in through impurities. 
 
 Lustre is one of the first characters the eye will observe, 
 but its variation under most species is wide, and often it 
 is of little value. State of aggregation and fracture for the 
 most part serve to distinguish only varieties. 
 
 Hardness is also often a varying character, the range 
 under some species being from 1 to 6 in the scale of hard- 
 ness ; and still its indications are generally important. 
 
 Crystalline form and cleavage are always important when 
 observable. 
 
 
 
 *In using the spiral balance of Jolly (page 65), the spiral spring is put at any de- 
 sired height by means of the sliding rod C. The stand B is raised so that the lower 
 pan, d, shall be in the water, while the other, c, is above it. The position of the in- 
 dex, or signal, m, is then noted, by sighting across it and observing that the index 
 and the image of it in the mirror are in the same horizontal line ; let s stand for it. 
 Next put the fragment of the mineral in ¢, and drop the stand B until the lower pan 
 hangs free in the water, and note the position of m, which we may represent by ¢; 
 ¢—s will equal the weight in the air. Now place the fragment in the lower pan, and 
 #fter adjusting again the stand B, the position of m is noted as before; call it v. 
 fee wy = loss of weight in water. From these values the specific gravity isat once 
 obtained. 
 
380 DETERMINATION OF MINERALS. 
 
 Taste is of limited value, as few minerals are sufficiently 
 soluble ; but among soluble minerals it is easily observed, 
 and often decisive. 
 
 Action of acids, cold or hot, in trials as to effervescence, 
 solubility, gelatinizing or not, and in making solutions for 
 examination with other reagents, is a very important means 
 of distinguishing species. 
 
 Blowpipe reactions are easily obtained, and of the high- 
 est value. 
 
 Specific gravity is an important reliance. 
 
 Refraction and polarization afford valuable criteria for 
 distinguishing species, and in a few cases no other means 
 are so reliable short of chemical analysis. 
 
 The following hints may be of service to the beginner in 
 the science, by enabling him to overcome a difficulty in the 
 outset, arising from the various forms and appearance of the 
 minerals quartz and limestone. Quartz occurs of nearly 
 every color, and of various degrees of glassy lustre to a dull 
 stone without the slightest glistening. The common gray- 
 ish cobble-stones of the fields are usually quartz, and others 
 are dull red and brown; from these there are gradual transi- 
 tions to the pellucid quartz crystal that looks like the best 
 of glass. Sandstones and freestones are often wholly quartz, 
 and the-seashore sands are mostly of the same material. It 
 is therefore probable that this mineral will be often en- 
 countered in mineralogical rambles. Let the first trial of 
 specimens obtained be made with a file, or the point of a 
 knife, or some other means of trying the hardness ; if the 
 file makes no impression, there 1s reason to suspect the 
 mineral to be quartz; and if on breaking it, no regular 
 structure or cleavage plane is observed, but it breaks in all 
 directions with a similar surface and a more or less vitreous 
 lustre, the probability is much strengthened that this con- 
 clusion is correct. ‘Che blowpipe may next be used ; and 
 if there is no fusion produced by it in a careful trial there 
 can be little doubt that the specimen is in fact quartz. 
 
 Calcite (calcium carbonate), including limestone, is an- 
 other very common species. If the mineral collected is 
 rather easily impressible with a file, it may be of this spe- 
 cies; if it effervesces freely when placed in a test-tube con- 
 taining dilute hydrochloric acid, and is finally dissolved, the 
 probability of its being carbonate of lime is increased ; if 
 
DETERMINATION OF MINERALS. 381 
 
 the blowpipe produces no trace of fusion, but a brilliant 
 light from the fragment before it, but little doubt remains 
 on this point. Crystalline fragments of calcite break with 
 three equal oblique cleavages. 
 
 Familiarized with these two Protean minerals by the 
 trials here alluded to, the student has already surmounted 
 the principal difficulties in the way of future progress. 
 Frequently the young beginner, who has devoted some 
 time to collecting all the different colored stones in his 
 neighborhood, on presenting them for names to some prac- 
 tised mineralogist, is a little disappointed to learn that, 
 with two or three exceptions, his large variety includes 
 nothing but limestone and quartz. Ie is perhaps gratified, 
 however, at being told that he may call this specimen yel- 
 low jasper, that red jasper, another flint, and another horn- 
 stone, others chert, granular quartz, ferruginous quartz, 
 chalcedony, prase, smoky quartz, greasy quartz, milky 
 quartz, agate, plasma, hyaline quartz, quartz crystal, basa- 
 nite, radiated quartz, tabular quartz, etc., etc.; and it is 
 often the case, in this state of his knowledge, that he is 
 best pleased with some treatise on the science in which 
 all these various stones are treated with as much promi- 
 nence as if actually distinct species; being loth to receive 
 the unwelcome truth, that his whole extensive cabinet con- 
 tains only one mineral. But the mineralogical student has 
 already made good progress when this truth is freely ad- 
 mitted, and quartz and limestone, in all their varieties, 
 have become known to him. | 
 
 The student should be familiar with the use of the blow- 
 pipe and the reactions, as explained on pages 82 and 85 ; 
 and it would be still better if a fuller treatise on the subject 
 had been carefully studied. He should be supplied with the 
 three acids in glass-stoppered bottles ; a fourth bottle con- 
 taining hydrochloric acid diluted one-half with water, for 
 obtaining effervescence with carbonates ; test tubes ; and 
 also the ordinary blowpipe apparatus and tests, including 
 platinum wire, platinum forceps, glass tube, “‘ cobalt solu- 
 tion,” litmus and turmeric paper, etc. 
 
 Also the following : : 
 
 A small file, three-cornered or flat, for testing hardness. 
 
 A knife with a pointed blade of good steel, for trying 
 hardness. It may be magnetized, to be used as a magnet, 
 though a good horseshoe magne¢ of small size is better. _ 
 
382 DETERMINATION OF MINERALS. 
 
 The series of crystallized minerals, constituting the scale 
 of hardness (see page 63). Diamond and tale are least es- 
 sential. 
 
 Cutting pliers, for removing chips of a mineral for blow- 
 pipe or chemical assay. 
 
 A pocket-lens. 
 
 A hammer weighing about two pounds, resembling a 
 stone-cutter’s hammer, having a 
 flat face, and at the opposite 
 end an edge having the same 
 direction as the handle. The 
 handle should be made of the 
 best hickory, and the mortise to 
 receive it should be as large as the handle. A foot scale 
 should be marked on the handle of the hammer, divided 
 into inches, the smallest divisions needed. It will be often 
 of use in getting out a yard-stick, or a ten-foot pole, for 
 large measurements. A similar hammer, having the upper 
 part prolonged to a blunt point, to be used like a pick, is 
 often convenient. 
 
 A hammer of half a pound weight, like the figure, to be 
 used in trimming specimens. 
 
 A small jeweler’s hammer, for trying the malleability of 
 globules obtained by the blowpipe, and for other purposes, 
 and a small piece of steel for an anvil. 
 
 Two steel chisels, one six inches long, and the other three. 
 When it is desired to pry open seams in rocks with the 
 larger chisel, two pieces of steel plate should be provided to 
 place on opposite sides of the chisel, after an opening is ob- 
 tained; this protects the chisel and diminishes friction 
 while driving it. 
 
 For blasting, if this is desired : ; 
 
 Three hand-drills 18, 24, and 36 inches long, an inch in 
 diameter. The best form is a square bar of steel, with a 
 diagonal edge at one end. The three are designed to follow 
 one another. 
 
 A sledge-hammer of six or eight pounds weight, to use 
 in driving the drill. 
 
 A sledge-hammer of ten or twelve pounds weight, for 
 breaking up the blasted rock. 
 
 A round iron spoon, at the end of a wire fifteen or eigh- 
 teen inches long, for removing the pulverized rock from the 
 drill-hole. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
DETERMINATION OF MINERALS. 033 
 
 A crowbar, a pickaxe, and a hoe, for removing stones and 
 earth before or after blasting. 
 
 Cartridges of blasting powder, to use in wet holes. They 
 should one-third fill the drill-hole. After the charge is put 
 in, the hole should be filled with sand and gravel alone with- 
 out ramming. If any ramming material is used, plaster of 
 Paris is the best, which has been wet and afterwards scraped 
 to a powder. 
 
 Patent fuse for slow match, to be inserted in the car- 
 tridge, and to lead out of the drill-hole. 
 
 The table beyond is prepared especially to aid in instruc- 
 tion, and comprises, with few exceptions, only the species 
 that are described in large type through the work, exclusive 
 of the hydrocarbon compounds. The following abbrevia- 
 tions are used in it, in addition to those explained on page 
 90. With reference to colors: dnh, brownish; bkh, black- 
 ish ; gnh, greenish ; gyh, grayish ; rdh, reddish. The acids: 
 mit., nitric acid ; sulph. acid, sulphuric acid ; HCl., nydro- 
 cloric acid ; sw/ph., sulphurous or sulphurous acid. 
 
 Reactions : gelatinizing with acid, see page 81 5 reaction 
 for sulphur with soda, see page 89 ; blue or red color with 
 cobalt solution, see page 88; hydrous, yielding water in a 
 closed tube ; anhydrous, not yielding water in a closed tube, 
 or only traces, see page 86; B.B. lithiwm-red color, see 
 page 87; B.B. green flame due to boron, see page 87 ; coal 1s 
 used for charcoal; fus. for fusible; infus. for infusible ; 
 _ sol. for soluble ; st. for streak. , 
 
 In using the blowpipe it is important to remember that 
 a trial of fusibility with the forceps, if not at once pro- 
 ducing fusion, should be made on a piece of the mineral not 
 larger than the fourth of an ordinary pin-head, and it should 
 be either oblong and slender, or thin, and be made to pro- 
 ject considerably beyond the points of the forceps, lest 
 the forceps carry off the heat, and cause a failure where 
 there ought to be success. Further, it should be in mind, 
 that in using charcoal, a white coating is always a conse- 
 quence of burning it, since the ash from its own combustion 
 is white. Again, before testing for sulphur by means of 
 soda and a polished surface of silver, it is necessary to try 
 the flame and the soda for sulphur. Gas-flame always con- 
 tains traces of sulphur, and sometimes too much for safe 
 conclusions in this trial. 
 
O84 _ DETERMINATION OF MINERALS. 
 
 A mincralogist sometimes has occasion to measure dis- 
 tances, and by the following method he may make himself 
 quite an accurate odometer : 
 
 Let him first find, or make, along a roadside, a measured 
 distance of 800 to 1,000 feet, and then walk it at his ordi- 
 nary walking pace three or four times, and note the number 
 ‘of steps. He will thus ascertain the actual length of his 
 pace, and also find that in his ordinary walk it does not 
 differ much from thirty inches ; it may be an inch or two 
 less, or one, two, or three more than this. ' Now four times 
 thirty inches is ten feet. If then, as he walks, he counts 
 one for every fourth step, each unit in the count will stand 
 ' for ten feet nearly, and 100, for 1,000 feet nearly. If his 
 pace is thirty-one inches, let him add a unit for every 
 thirty in the counting, or, which is the same thing, call his 
 thirty thirty-one, and the needed correction will be made; 
 or if his step is twenty-nine and one-half inches, subtract 
 one from every sixty in the counting, or in other words du- 
 plicate the sixty. Or the correction may be made at the 
 end of the pacing; if at 600, this number, after adding 
 a thirtieth, becomes 620; and the distance would hence be 
 6,200 fect. With a little practice the counting may be 
 carried on almost unconsciously, and when the thoughts 
 are elsewhere; that is, unless there is a talking friend by 
 one’s side. 
 
 An instrument, called a pedometer, of the shape and size 
 of a small watch, is to be had of instrument makers, which, 
 if carried in the waistcoat pocket, will do the registering for 
 the pedestrian and note the distance, without any attention 
 on his part. But the odometer explained above, when once 
 in working order, is always at hand. 
 
 SYNOPSIS OF THE ARRANGEMENT. 
 I. ELEMENTS. 
 
 . Lustre metallic ; liquid. 
 
 . Lustre metallic ; malleable and eminently sectile. 
 
 . Lustre metallic ; brittle ; B.B. on coal, wholly volatile, with no 
 sulphurous fumes. 
 
 . Lustre metallic ; brittle ; H.=1-2; leaves a trace on paper ; B.B. 
 on coal, infusible, no fumes or odor. 
 
 . Unmetallic ; burns readily with a blue flame. 
 
 . Lustre adamantine ; H.=10.. 
 
 Ooo» -& Wwe 
 
DETERMINATION OF MINERALS. 385 
 
 II. MINERALS NOT ELEMENTS, THAT B.B. ON 
 COAL ARE WHOLLY VOLATILE. 
 
 1. Lustre metallic ; streak metallic. 
 2. Lustre unmetallic ; streak same as color. 
 
 III. COMPOUNDS, OF GOLD, SILVER, COPPER, 
 LEAD, TIN, MERCURY, CHROMIUM, COBALT, 
 MANGANESE: yielding, on heating, a malleable, or 
 liquid (for mercury ores), metallic globule, as explained 
 on pages 389-393, or else affording a decisive blowpipe 
 reaction, proving the presence of one or more of these 
 metals. 
 
 A. Yielding a malleable globule B.B. on coal with, if not 
 without, soda. 
 
 1. Compounds of Gold. 
 2. Compounds of Silver. 
 3. Compounds of Copper. 
 4. Compounds of Lead. 
 5. Compounds of Tin. 
 
 B. Yielding drops of mercury with soda in a closed tube. 
 
 1. Compounds of Mercury. 
 
 C. A decisive reaction with borax or salt of phosphorus 
 for chromium, cobalt, or manganese. 
 
 1. Compounds of Chromium. 
 2. Compounds of Cobalt. 
 3. Compounds of Manganese. 
 
 IV. MINERALS OF METALLIC OR SUBMETALLIC 
 LUSTRE, NOT INCLUDED IN PRECEDING 
 DIVISIONS. 
 
 1. Yielding fumes in the open tube or on coal, but not 
 
 wholly yaporizable. 
 25 
 
386 DETERMINATION OF MINERALS. 
 
 A. Streak metallic. 
 B. Streak unmetallic. 
 a. Fumes sulphurous only. 
 b. Fumes arsenical, with or without sulphurous. 
 
 2, Not yielding fumes of any kind; streak unmetallic. 
 
 A. B.B. easily fusible, giving a magnetic bead ; lustre sub- 
 metallic. 
 B. Infusible, or nearly so. 
 a, Reaction for iron ; anhydrous. 
 b. Reaction for iron ; hydrous. 
 c. Reaction for chromium or titanium. 
 g. Reaction for osmium with nitre. 
 
 Vy. MINERALS OF UNMETALLIC LUSTRE. 
 
 i. fiaving an acid, alkaline, alum-like, or styptic taste. 
 
 CARBONATES : Taste alkaline ; effervescing with HCl. 
 SULPHATES: No effervescence ; reaction for sulphur 
 with soda. 
 
 _ NITRATES: With sulph. acid, reddish acrid fumes ; 
 no action with HCl; deflagrate. 
 
 ._ CHLORIDES: With sulph. acid, acrid fumes of HCl; 
 no fumes with HCl. 
 
 . BORATES : No effervescence ; reaction for boron when 
 
 moistened with sulph. acid. 
 
 Ho a WP 
 
 2, Not having either of the above-mentioned kinds of 
 taste. 
 
 A. CARBONATES : Effervescing with HCl. 
 
 a. Infusible ; assay alkaline after ignition. 
 
 b. Infusible; become magnetic and not alkaline, on 
 ignition. 
 
 c. Infusible; B.B. on coal with soda, zinc oxide 
 vapors. 
 
 d. Infusible ; B.B. on coal reaction for nickel. 
 
 ¢. Fusible ; assay alkaline after ignition. 
 
 B. SULPHATES : Reaction for sulphur with soda, 
 a, Fusible ; assay alkaline after fusion. 
 }. Fusible ; reaction for iron, 
 c. Infusible, 
 
DETERMINATION OF MINERALS. 387% 
 
 C. ARSENATES : on coal arsenical fumes. 
 D. SILICATES, PHOSPHATES, OXIDES: 
 
 Species not included in the preceding subdivisions. 
 
 I. STREAK DEEP RED, YELLOW, BROWNISH-YELLOW, GREEN, OR 
 BLACK. 
 
 A. Infusible, or fusible with difficulty. 
 B. Fusible without much difficulty. 
 
 Il STREAK GRAYISH OR NOT COLORED. 
 1. Infusible. 
 
 A. Gelatinize with acid, forming a stiff jelly. 
 B. Not forming a stiff jelly ; hydrous. 
 a. Blue color with cobalt solution. 
 b. Reddish or pink color with cobalt solution. 
 c. Not blue or red with cobalt solution. 
 C. Not forming a stiff jelly ; anhydrous. 
 a. Blue color with cobalt solution. 
 b. Not blue or reddish color with cobalt solution. 
 
 2. Fusible with more or less difficulty. 
 
 A. Gelatinize and form a stiff jelly. 
 
 a. Hydrous ; fuse easily. 
 
 b. Hydrous ; fuse with much difficulty. 
 
 c. Anhydrous. 
 
 a. No reaction for sulphur; no coating on coal. 
 f. Reaction for sulphur with soda. 
 B. Not gelatinizing. 
 
 1. Structure eminently micaceous ; folia tough, pearly, 
 and H. of surface of folia not over 3°5 ; anhydrous 
 or hydrous. 
 
 2. Structure not eminently micaceous. 
 
 a. Hydrous. 
 a. No reaction for phosphorus, or boron. 
 . H.=1 to 3; lustre not at all vitreous. 
 +H. H.=3'5-6° 5; lustre of cleavage sur- 
 face sometimes pearly ; elsewhere vi- 
 treous. 
 f. Reaction for phosphorus or boron. 
 b. Anhydrous. 
 a, B.B. lithium-red flame. 
 f. B.B. boron reaction (green flame). 
 y. B.B. reaction for titanium. 
 6. B.B. reaction for fluorine or phosphorus. 
 é. B.B. reaction for iron. 
 S. B.B. no reaction for iron; not of the pre- 
 ceding subdivisions, 
 
388 DETERMINATION OF MINERALS. 
 
 I. ELEMENTS. 
 
 1. Lustre metallic ; liquid. 
 
 MERCURY, p. 128. This is the only metallic mineral which is liquid 
 at the ordinary temperature and atmospheric pressure. 
 
 9. Lustre metallic ; malleable and eminently sectile. 
 
 GOLD, p. 109. G.—15-19°5 ; yellow ; fusible ; not sol. in nitric acid 
 or HCl, but sol. in aqua regia. 
 
 PLATINUM, p. 124. G.—16-19 ; nearly white ; infusible ; insol. in 
 nitric acid. 
 
 PALLADIUM, p. 127. G.—11'3-11°8 ; grayish-white ; diff. fusible ; 
 sol. in nitric acid. 
 
 SILVER, p. 116. G.—10-11°1; white ; fusible ; sol. in nitric acid, 
 and deposited again on copper. 
 
 COPPER, p. 131. G.=8°84; copper-red ; fus.; sol. in nitric acid, 
 and the solution becomes sky-blue when ammonia is added 
 
 IRON, p. 171. G.=7:3-78; iron-gray; attracted by the magnet. 
 
 The only other mineral of metallic lustre that is also malleable and 
 eminently sectile is argentite, a silver sulphide, along with two others 
 of like composition but different crystallization. 
 
 2 Lustre metallic; brittle ; B.B. wholly volatile, 
 but give off no sulphurous fumes. 
 BISMUTH, p. 101. G.=978 ; reddish-white ; on coal a yellow coat- 
 
 ing ; fumes inod. 
 ANTIMONY, p. 100. G. —66-6'7; tin-white ; fumes dense wh., inod. 
 ARSENIC, p. 98. G.=5'9-6 ; tin-white ; fumes white, alliaceous. 
 TELLURIUM, p. 96. G.—6'1-6°3 ; tin-white ; fus.; fumes white ; 
 flame green. 
 
 The only other mineral that is wholly vol atile, and also gives off no 
 sulphurous fumes, is allemontite, an antimony arsenide. 
 
 4. Lustre metallic; H.=1-2; B.B. on coal infusible ; 
 no fumes. © 
 
 GRAPHITE, p. 107. 
 
 5. Lustre unmetallic; takes fire readily in the flame 
 of a candle, and burns with a blue flame. 
 
 SULPHUR, p. 94. 
 
 6. Lustre adamantine ; H.=10. 
 DIAMOND, p. 108. Hasily scratches corundum or sapphire. 
 
DETERMINATION OF MINERALS. 889 
 
 I, MINERALS, NOT ELEMENTS, THAT 
 ARE WHOLLY VOLATILE B.B. 
 ON COAL. 
 
 1. Lustre metallic ; streak metallic. 
 
 TETRADYMITE, p. 102. G.=7-2-7-9; pale Steel-gray ; so soft as 
 to soil paper ; on coal white fumes ; flame bluish-green; sometimes 
 sulph. odor ; in open tube, a coating which fuses to white drops. 
 
 BISMUTHINITE, p. 102. G.=6-4-7:2; whitish lead-gray; on coal 
 yellow coating and sulph. odor. 
 
 STIBNITE, p. 100. G.=4:5-452; lead-gray; on coal dense wh. 
 fumes and wh. coating. 
 
 2. Lustre unmetallic ; streak same nearly as color. 
 
 ORPIMENT, p. 99. Lemon yellow ; on coal burns, odor alliaceous. 
 
 REALGAR, p. 99. Bright red; on coal burns, odor alliaceous. 
 
 ARSENOLITE, p. 99. White; on coal, odor alliaceous. 
 
 VALENTINITE, p. 101. White; on coal dense wh. fumes, inod. 
 
 CINNABAR, p. 128. Red; in open tube, sulph. odor, coating of 
 mercury globules. 
 
 SALMIAK, p. 230. White ; saline and pungent taste ; on coal, fumes 
 of ammonia. 
 
 III. COMPOUNDS OF GOLD, SILVER, MER. 
 CURY, COPPER, LEAD, TIN, CHRO. 
 MIUM, COBALT, MANGANESE. 
 
 A. Yielding a malleable globule B.B. on coal, with 
 or without soda. 
 
 1. COMPOUNDS OF GOLD. 
 
 Yield gold, or an alloy of gold and silver, B.B. on coal. The TELLU- 
 RIUM ORES, pp. 115, 116, give a coating of drops of tellurous acid in 
 open tube. 
 
 2. COMPOUNDS OF SILVER. 
 B.B. easily fusible ; G. above 5; yield, with few exceptions, a glo- 
 bule of silver (white and malleable), on coal, with soda, if not without ; 
 
 and, in the exceptions, silver globule obtained by cupellation. All 
 have metallic lustre excepting cerargyrite, bromyrite, and iodyrite. 
 
390 DETERMINATION OF MINERALS. 
 
 a. EMINENTLY SECTILE. 
 
 ARGENTITE, p. 117. G.=7 2-7-4; lustre metallic ; on coal sulph. 
 fumes. 
 
 CERARGYRITE, p. 120. G.—5-3-5'°6 ; lustre like that of white, 
 gray, or greenish to brownish wax. 
 
 b. NOT SECTILE ; ON COAL ODOROUS FUMES. 
 
 SULPHIDES, p. 118. Gives sulph. odor. 
 ARSENICAL ORES, pp. 119, 120. Alliaceous fumes. 
 SELENIDES, p. 118. Horse-radish odor. 
 
 c. NOT SECTILE ; ON COAL FUMES OF ANTIMONY OR TELLURIUM. 
 
 ANTIMONIAL ORES, pp. 119, 120. Dense white fumes of anti- 
 mony; with also, if sulphur is present, sulph. fumes. 
 
 TELLURIDES, p. 118. In open tube coating which fuses to drops 
 of tellurous acid. 
 
 STROMEYVERITE, p. 119. Contains copper, and requires cupellation 
 in order to obtain a globule of silver. 
 
 3. COMPOUNDS OF COPPER. 
 
 Unless iron is present, a globule of metallic copper is obtained with 
 soda, if not without, on coal; with a nitric acid solution and ammonia 
 in excess a bright blue color; moistened with HCl the blue flame of 
 chloride of copper; and a clean surface of iron in the nitric solu- 
 tion becomes coated with copper. 
 
 1. METALLIC LUSTRE. 
 
 SULPHIDES, pp. 182-136. On coal or in open tube sulph. fumes. 
 ARSENIDES, SELENIDES, p. 135. 
 ANTIMONIAL SULPHIDES, p. 135, 136. 
 
 2, LUSTRE UNMETALLIC ; B.B. NEITHER ON COAL NOR IN OPEN 
 TUBE ANY ODOROUS FUMES ; NO TASTE. 
 
 SES EN = p. 186. H. —3-5-4; G.—5'8-6'2; isometric: deep red, streak 
 
 bnh-red. 
 
 ATACAMITE, p. 136. Darkish bright green, streak gnh; B.B. on 
 coal fuses, coloring O.F. azure-blue, with a green edge ; easily sol. 
 in acids. ‘ 
 
 PHOSPHATES, p. 139. 
 
 MALACHITE, p. 140. H.—3-4; G.=3°7-4; light to deep green; ef- 
 fervesces with HCl. 
 
 AZURITE,, p. 141. H.—3°5-4:5; G.=3'5-3°9; deep blue ; effervesces 
 with HCl. 
 
 DIOPTASE, p. 141. H.=5; G. —3:25-3'35; emerald-green; B.B. in- 
 fusible. 
 
 CHRYSOCOLLA, p. 142. Bluish-green; B.B. infusible. 
 
DETERMINATION OF MINERALS. 391 
 
 8. LUSTRE UNMETALLIC; B.B. ON COAL, OR IN CLOSED TUBE, ODOROUS 
 FUMES OF ARSENIC OR SULPHUR, OR REACTION FOR SULPHUR. 
 
 ARSENATES, p. 189. On coal arsenical fumes. 
 CHALCANTHITE, p. 187. Blue; taste nauseous; astringent. 
 Also Stromeyerite, Stannite, Bournonite give reactions for copper. 
 
 4, COMPOUNDS OF LEAD. 
 
 Yield B.B. on coal a dark lemon-yellow coating; finally, with soda, 
 if not without, a globule (metallic and malleable) of lead is ob- 
 tained ; but by continued blowing with O.F’. the lead all goes off in 
 fumes, leaving other more stable metals (silver, etc.) behind.” Sul- 
 phurous, selenious and tellurous fumes easily obtained either on 
 coal or in an open tube from the sulphide, selenide, tellurides ; and 
 arsenical or antimonial fumes from ores containing arsenic or anti- 
 mony. None have taste. 
 
 1. LUSTRE METALLIC. 
 
 GALENITS, p. 145. H.=2°5; G.=7-2-7'7 ; cleavage cubic eminent ; 
 lead-gray, streak same ; in open tube sulph. 
 
 SHLENIDES, TELLURIDES, ANTIMONIAL and ARSEN- 
 ICAL SULPHIDES, page 149. 
 
 9. LUSTRE UNMETALLIC ; NO ODOROUS FUMES, OR REACTION FOR 
 SULPHUR. 
 
 IMINIUM, p. 149. Bright red, streak same. 
 
 CROCOITH, p. 150. Monoclinic ; bright red, streak orange-yellow ; 
 B.B. with salt of phosphorus emerald-green bead. 
 
 PYROMORPHITE, p. 151. Hexagonal; bright green to brown, 
 rarely orange-yellow ; streak white. B.B. fuses easily, coloring 
 flame bluish-green. 
 
 CERUSSITEH, p. 152. Trimetric, often in twins; H.=—8-3°5 ; 
 G.=6-4-68; white, gyh; lustre adamantine; often tarnished to 
 grayish metallic adamantine. Effervesces in dilute nitric acid. 
 
 8. UNMETALLIC ; REACTION FOR SULPHUR. 
 
 ANGLESITH, page 150. Trimetric; white, gyh; fuses in flame of 
 candle ; B.B. reaction for sulphur ; no effervescence with acids. 
 
 5. COMPOUNDS OF' TIN. 
 
 CASSITERITE, p. 160. H.=6-7; G.=6:4-7'1; brown, gyh, ywh, 
 black ; B.B. infusible; on coal with soda a globule of tin, yield 
 
 no fumes. , ; 
 Stannite, p. 158. A copper, iron, and tin sulphide, does not give 
 
 B.B. a metallic malleable globule, 
 
1 
 
 392 DETERMINATION OF MINERALS. 
 
 B. Yield drops of mercury in closed tube with or 
 without soda. 
 
 COMPOUNDS OF MERCURY. 
 
 CINNABAR, p. 128. H.=2-2'5; G.=8-9; bright red, bnh red, gyh ; 
 streak scarlet. 
 AMALGAM, p. 117. H.=3-3'5; G. —13-14 ; silver-white; yields 
 silver B.B. on coal. 
 Spaniolite, p. 136, a variety of tetrahedrite, yields mercury. 
 
 CG. No malleable globule; decisive reaction with borax 
 or salt of phosphorus for chromium, cobalt, or 
 manganese. | 
 
 1. COMPOUNDS OF CHROMIUM. 
 Give with borax an emerald-green bead in both flames. 
 
 CHROMITE, p. 180. H.=—5'5; G.=4:3-4°5; isometric, often in 
 octahedrons, massive ; submetallic ; buh iron-black, streak brown ; 
 B.B. on coal becomes magnetic ; with borax, a bead which is 
 emerald-green on cooling. 
 
 CROCOITH, p. 150. H.=25-3; G.=5'9-6:1; bright red, streak 
 orange; B.B. fuses very easily, on coal globule of lead, and with 
 salt of phosphorus emerald-green bead. Phenicochroite ané Vauque- 
 linite are other lead chromates. 
 
 2. COMPOUNDS OF COBALT. 
 
 Give a blue color with borax after, if not before, roasting. 
 [When much nickel or iron is present the blue color is not ob- 
 tained ; and species or varieties of this kind are not here included. | 
 
 1. LUSTRE METALLIC. 
 
 COBALTITE, p. 165. H.=5°5; G.—6-6'3; isometric and pyrito- 
 hedral ; rdh silver-white, streak grayish-black ; B.B. on coal sulph. 
 and arsen. fumes, and a magnetic globule. 
 
 SMALTITE, p. 165. H.—55-6; G.=-64-72,; tin-white, streak 
 gyh black ; B.B. on coal alliaceous fumes ; most varieties fail to give 
 the blue color immediately with borax, because of the iron and 
 nickel present. 
 
 LINNZITE, p. 164. H.=5°5; G.=—4'8-5; isometric; pale steel- 
 gray, copper-red tarnish, streak bkh gray. B.B. on coal sulph. 
 fumes. 
 
 2 LUSTRE UNMETALLIC. 
 
 ERYTHRITE, p. 167. H.=15-2; G.=2:95; monoclinic, one 
 highly perfect cleavage, also earthy ; rose-red, peach-blossom red, 
 streak reddish ; B.B. fuses easily ; yields water. 
 
F DETERMINATION OF MINERALS. 393 
 
 BIEBERITE, p.168. A cobalt sulphate. 
 REMINGTONITE, p. 168. A hydrous cobalt carbonate. 
 
 3. COMPOUNDS OF MANGANESE. 
 
 Give an amethystine globule in O.F. with borax. [The globule 
 looks black if too much of the manganese mineral is used, and with 
 a large excess may be opaque. | 
 
 1. GIVES OFF CARBONIC ACID WHEN TREATED WITH DILUTE HCl; 
 LUSTRE UNMETALLIC. 
 
 RHODOCHROSITE, p. 191. H.=3:5-4:5 ; G.=3:4-8-7; rose-red. 
 
 Also manganese-bearing varieties of calcite, dolomite, ankerite, side- 
 rite, all of which have the cleavage and general form of rhodochro- 
 site; when containing a few per cent. of manganese they often turn 
 black on exposure. 
 
 2. TREATED WITH HCl YIELDS CHLORINE FUMES. 
 
 MANGANITE, p. 189. H.=4; G.=42-4:-4; in oblong trimetric 
 prisms ; grayish-black, streak reddish-brown ; lustre submetallic ; 
 B.B. infusible ; yields water. 
 
 PSILOMELANE, p. 189. H.=5-7; G.=8-7-4:7; amorphous ; black, 
 streak brownish-black ; submetallic ; B.B. infusible ; yields water. 
 
 Wad is similar, but often contains cobalt. 
 
 PYROLUSITE, p. 188. H.=2-2'5; G.=4:82 ; in stoutish trimetric 
 crystals; metallic; dark steel-gray, streak black or bluish-black ; 
 B.B. infusible ; yields no water. 
 
 BRAUNITE and HAUSMANNITE (p. 189) are other anhydrous 
 manganese oxides. 
 
 FRANKLINITE, p. 179. H.=5-5-65; G.=5-5-1; in octahedrons 
 and massive ; iron-black, streak dark reddish brown ; B.B. infusi- 
 ble; but little chlorine with H Cl. 
 
 3. CO. OR Cl NOT GIVEN OFF WHEN TREATED WITH HCl; 
 ANHYDROUS. 
 
 RHODONITE, p. 247. H.=5-5-65; G.=3-4-8:68; rose-red; B.B. 
 fuses easily. 
 
 TRIPLITE, p. 191. H.=—55; G.=3-4-3:8; brown to black; B.B. 
 fuses very easily, globule magnetic ; sol. in HCl. 
 
 HELVITE, p. 256. H.=—6-6:5; G.=3-1-3°3; in yellowish tetrahe- 
 hedrons ; B.B. fuses easily, 
 
 SPESSARTITE (Manganesian Garnet), p. 258. H.—6°5-7; G.=3-7- 
 4:4; in dodecahedrons and trapezohedrons ; red, brownish-red ; 
 
 ' B.B. fuses easily. 
 
 TEPHROITEH, p. 256. H.=5-5-6; G.=4-4-12 ; reddish to brown 
 and gray ; B.B. fuses not very easily ; gelat. in HCl, 
 
 Knebelite, p. 256, is related, and also gelatinizes, 
 
394 DETERMINATION OF MINERALS. 
 
 TIAUFIRITE, p. 188. H.=4; G.—3°'46; isometric ; reddish brown, 
 streak brownish-red. B.B. yields sulphur, after roasting reaction 
 for manganese. 
 
 ALABANDITE, p. 188. H.=3'5-4; G.—4; submetallic, iron-black; 
 streak green; B.B. on coal sulphur, after roasting reaction for 
 manganese. 
 
 Vesuvianite, epidote, axinite, ilvaite, géthite, include varieties that 
 give reaction for manganese. 
 
 
 
 IV. MINERALS OF METALLIC OR SUB- 
 METALLIC LUSTRE NOT INCLUDED 
 IN PRECEDING DIVISIONS. 
 
 —————$—$— 
 
 1. YIELDING FUMES IN THE OPEN TUBE 
 OR ON COAL, BUT NOT WHOLLY 
 VAPORIZABLE. 
 
 A. STREAK METALLIC. 
 
 MOLYBDENITE, p. 96. H.--1-1'5; G.=4'4-4'8; lead-gray, and 
 leaves trace on paper ; B.B. on coal sulphurous fumes 
 
 BISMUTHINITE, p. 102. H. —2;G.=6'4-7°2; lead-gray, whitish ; 
 B.B. on coal sulphurous fumes, and yellow bismuth oxide ; sol. in 
 hot nitric acid and a white precip. on diluting with water 
 
 B. STREAK UNMETALLIC. 
 
 a. FUMES SULPHUROUS ONLY. 
 
 PYRITE, p. 172. H. =6-6'°5 ; G.=4'8-5'2: isometric and pyritohe- 
 dral ; pale brass-yellow, streak gnh black, bnh black; B.B. on 
 coal, fuses to a magnetic globule. 
 
 MARCASITE, p. 174. H.—6-65; G.=—468-4'89; trimetric ; pale 
 bronze-yellow ; streak gyh black, bnh black ; B.B. like pyrite. 
 
 PYRRHOTITE, p. 174. H.—3°5-45; G.—4°4-4°68 ; hexagonal ; 
 bronze-yellow, rdh ; streak gyh black ; slightly magnetic ; B.B. 
 fuses to a magnetic mass. 
 
 MILLERITE, p. 164. H.=3-35; G.=—4:6-5°7; rhombohedral, 
 usually in acicular or capillary forms, also in fibrous crusts ; brass- 
 yellow, somewhat bronze-like ; B.B. fuses to a globule, reacts for 
 nickel. 
 
 LINNZITEH, p. 164. H.=9°5: G.—4:8-5; isometric; pale steel- 
 gray, copper-red tarnish ; streak blackish-gray ; B.B. on coal fuses 
 
DETERMINATION OF MINERALS. 395 
 
 to a magnetic globule, after roasting gives reactions for nickel, 
 cobalt, and iron. 
 
 SPHALERITE, p. 154. H.=3'5-4; G.=3-9-4:2; isometric; lustre 
 submetallic ; streak nearly uncolored ; nearly infusible alone and 
 with borax ; on coal a coating of zinc oxide. 
 
 b. ARSENICAL FUMES, WITH OR WITHOUT SULPHUROUS. 
 
 ARSENOPYRITEH, p. 175. H.—5-6; G.—6-6°4; trimetric ; white, 
 gyb, streak dark gyh black. In closed tube, red arsenic sulphide 
 and metallic arsenic; B.B. on coal fuses to magnetic globule. 
 
 GERSDORFFITE, p. 166. H.=5'5; G.=5°6-6°9; isometric, py- 
 ritohedral; white, gyh, streak grayish-black. In closed tube 
 arsenic sulphide, on coal not magnetic, and reacts for nickel and 
 often cobalt. 
 
 NICCOLITEH, p. 166. H.—5-55; G.—73-7-7; hexagonal; pale 
 copper-red, streak pale bnh black; in open tube, coating of arsen- 
 ous acid ; B.B. on coal no sulph. fumes, fuses to globule which re- 
 acts for iron, cobalt and nickel. 
 
 SMALTITE, p. 165. H.—5:'5-6 ; G.=6°4-7:2 ; isometric ; tin-white ; 
 streak gyh black ; on coal, no fumes of sulphur or only in traces. 
 
 2. NOT YIELDING FUMES OF ANY KIND. 
 STREAK UNMETALLIC. 
 
 A. B.B. EASILY FUSIBLE, AND GIVING A MAGNETIC BEAD. 
 LUSTRE SUBMETALLIC. 
 
 ILVAITE, p. 263. H.=—5°5-6; G.—3-7-4:2; trimetric; gyh iron- 
 black, streak gnh or bnh black ; gelat. with H Cl. 
 
 ALLANITE, p. 263. H.=5'5-6; G.=3-42; monoclinic; bnh pitch- 
 black, streak gyh, bnh; B.B. fuses easily ; most varieties gelat. 
 with HCl. 
 
 WOLFRAMITE, p, 188. H.=—5-5°5; G.=7:1-7°6; monoclinic; gyh 
 black or bnh black ; B.B. fuses easily, and reacts for iron, manga- 
 nese, and tungsten. 
 
 B. INFUSIBLE OR NEARLY SO. 
 2. REACTION FOR IRON ; ANHYDROUS; II.=5-6°5. 
 
 MAGNETITE, p. 178. G.—4°9-5°2 ; isometric ; iron-black ; streak 
 black ; strongly magnetic. 
 
 MENACCANITE, p. 178. G.=4:5-5; rhombohedral ; iron-black : 
 streak submetallic, black to bnh red ; very slightly magnetic. 
 
 HEMATITH, p. 176. G.—4°5-5°3; rhombohedral; gyh iron-black, 
 in very thin splinters or scales blood-red by transmitted light ; 
 streak red ; sometimes slightly magnetic. 
 
 MARTITBH, p. 177. Same as hematite, but isometric. 
 
 TANTALITE, p. 184. G,=7-8; trimetric ; iron-black, streak rdh 
 brown to black, 
 
396 DETERMINATION OF MINERALS. © 
 
 FRANELINITE, p. 179. H.=5'5-6°5 ; G.—4°8-5:1; octahedral, 
 massive ; iron-black ; streak dark rdh brown ; slightly attracted 
 by magnet ; with soda reaction for manganese. 
 
 COLUMBITH, p. 1838. G.=—5 4-65; trimetric ; iron-black, gyh 
 black, streak dark red to black, often with a bluish steel-tarnish. 
 SAMARSKITH, p. 202. H.=5'5-7; G.—56-08; velvet-black, 
 pitch-black ; streak dark rdh brown ; B.B. glows ; fuses with dif- 
 
 ficulty. 
 
 b. REACTION FOR IRON ; HYDROUS; LUSTRE SUBMETALLIC. 
 
 LIMONITE, p. 181. G.—8°6-4; massive, often stalactitic and tube- 
 rose with surface sometimes highly lustrous, often subfibrous in 
 structure ; black, bnh black ; streak bnh yellow. 
 
 GOTHITE, p. 182. G.=4:0-44; trimetric; also fibrous and mas- 
 sive ; bkh brown; streak bnh yellow. 
 
 TURGITHE, p. 182. G.=3°6-4'68 ; fibrous and massive, looking like 
 limonite ; black, rdh black, streak red; in closed tube decrepitates, 
 which is not the case with githite and limonite. 
 
 C. REACTION FOR CHROMIUM OR TITANIUM. 
 
 CHROMITE, p. 180. H.—5-5; G.=4:3-46; isometric; submetal- 
 lic; buh iron-black, streak brown; B.B. with borax gives a bead 
 which on cooling is chfome-green. 
 
 RUTILE, p. 162. H.=6-65; G.=—4184:25; black, streak bnh; 
 reacts for titanium. Black varieties of brookite (p. 163), submetallic 
 in lustre, give same reaction. 
 
 Euzenite, p. 202 ; yttrotantalite, p. 202; wschynite, p. 202; ferguson- 
 ite, p. 202, and perofskite, p. 163, are submetallic in lustre. 
 
 d. HEATED WITH NITRE IN A MATRASS YIELDS FUMES OF OSMIUM. 
 
 IRIDOSMINE, p. 127. H.=6-7; G.=19-21:2; in small scales 
 from auriferous or platiniferous sands ; tin-white, gyh. 
 
 V. LUSTRE UNMETALLIC. 
 
 1. MINERALS HAVING AN ACID, ALKALINE, 
 ALUM-LIKE, OR STYPTIC TASTE. 
 
 A. CARBONATES : Taste alkaline ; effervescing with HCl. 
 
 NATRON, p. 229. Effloresces on exposu 
 TRONA, p. 230. Does not effloresce. 
 
DETERMINATION OF MINERALS. 397 
 
 B. SULPHATES : No effervescence; reaction B.B. on coal with soda 
 for sulphur. 
 
 MASCAGNITE, p. 231. Yields ammonia. 
 
 MIRABILITE, p. 226. Monoclinic, crystals stout; taste cool, 
 saline, bitter ; B.B. flame deep yellow. 
 
 EPSOMITE, p. 205. Trimetric, crystals ordinarily slender, spicule- 
 like ; taste bitter and saline ; B.B. flame not yellow. 
 
 ALUNOGEN, p.197. Taste like common alum. 
 
 KALINITE, MENDOZITE and other alums, p. 198. 
 
 MELANTERITE, p. 182. Green ; taste styptic ; reacts for iron. 
 
 CHALCANTHITE, p. 137. Blue ; reacts for copper. 
 
 MORENOSITE, p. 168. Green ; reacts for nickel. 
 
 BIEBERITE, p. 168. Reddish ; reacts for cobalt. 
 
 GOSLARITE, p. 156. White; reacts for zinc. 
 
 JOHANNITE, p.171. Emerald-green, reacts for uranium. 
 
 C. NITRATES : With sulphuric acid, reddish acrid fumes ; no action 
 with hydrochloric acid ; deflagrate. 
 
 NITRE, p. 228. Not efflorescent. Strong deflagration. 
 SODA-NITRE,, p. 229. Efflorescent. 
 NITROCALCITE, p. 214. Deflagration slight. 
 
 D. CHLORIDES : With sulphuric acid acrid fumes of HCl ; no fumes 
 \ with HCL. 
 
 SALMIAK, p. 230. Taste saline, pungent ; on coal, evaporates ; with 
 soda, odor of ammonia. 
 
 SYLVITE, p. 224. Taste saline ; B.B. flame purplish. 
 
 HALITE or COMMON SALT, p. 224. Taste saline; B.B. flame 
 yellow. 
 
 EK. BORATES. No effervescence with acids ; B.B. reaction for boron, 
 when moistened with sulphuric acid. 
 
 SASSOLITE, p. 97. Taste feedly acid ; B.B. very fusible. 
 BORAX, p. 227. Taste sweetish alkaline ; B.B. puffs up. 
 
 2. MINERALS NOT HAVING AN ACID, ALKA- 
 LINE, ALUM-LIKE OR STYPTIC TASTE. 
 
 A. CARBONATES: Effervescing with HCl. 
 
 A. INFUSIBLE ; ASSAY ALKALINE AFTER IGNITION. 
 
 CALCITE, p. 215. H. under 3°; G.=2°5-2'72; RA R=105° 5’, 
 with three easy cleavages parallel to R; colors various ; effervesces 
 readily with cold HCl ; anhydrous, . 
 
 \ 
 
398 DETERMINATION OF MINERALS. 
 
 ARAGONITE, p. 218. H.=3'5-4; G.=2.94; trimetric, cleavage im- 
 perfect ; otherwise like calcite. 
 
 DOLOMITE, p. 219. H.=3'5-4 ; G.=2-8-2°9 ; rhombohedral, RA 
 —106° 15'; colors various ; effervesces but slightly with cold HCl, 
 unless finely pulverized ; anhydrous. 
 
 MAGNESITE, p. 207. H.=85-4°5 ; G.—3-3'1 ; rhombohedral, RAF 
 =107° 29'; white, ywh, gyh; effervesces but slightly with cold 
 HCl; anhydrous. 
 
 HYDROMAGNESITE,, p. 207. H.=1-3'5 ; G.=2:14-2:18; hydrous. 
 
 B. INFUSIBLE ; BECOME MAGNETIC AND NOT ALKALINE AFTER 
 IGNITION. 
 
 SIDERITE, p. 185. H.=3:5-4:5; G.—3°7-3°9 ; rhombohedral, R: R 
 =107° ; cleavage as in calcite ; becomes brown on exposure, chang- 
 ing to limonite. 
 
 ANKERITEB, p. 186. H.=3°5-4; G.=2°9-3:1; RA R=106° 7; be- 
 comes brown on exposure. 
 
 Some kinds of calcite and dolomite contain iron enough to become 
 magnetic on ignition. 
 
 C. INFUSIBLE ; B.B. ON COAL WITH SODA, COATING OF ZINC OXIDE. 
 
 SMITHSONITE, p. 156. H.=5; G.=4-45; rhombohedral like 
 calcite; RA R=107° 40’; crystals often an acute rhombohedron ; 
 anhydrous. 
 
 HYDROZINCITEH, p. 157. H.=2-2:5; G.=8'6-3'8; white, gyh, 
 ywh, often earthy ; reacts for zinc ; hydrous. 
 
 D. INFUSIBLE ; B.B. ON COAL REACTION FOR NICKEL. 
 
 ZARATITH (Emerald nickel), p. 168. H.=8. Emerald green, streak 
 paler. 
 
 E. FUSIBLE; ASSAY ALKALINE AFTER IGNITION. 
 
 WITHERITE, p. 221. H.=3-3:75 ; G.=—4-29-4'35,; trimetric ; white, 
 ywh, gyh; B.B. fuses easily, flame ywh green ; anhydrous. 
 
 STRONTIANITE, p. 223 H.=3-5-4; G.=3'6-3°72 ; trimetric ; pale 
 green, gray, ywh, white; B.B. fuses only on thin edges, flame 
 bright red ; anhydrous. 
 
 BARYTOCALCITE, p. 222. Monoclinic. G.=3°6-3°66 ; B.B. nearly 
 like witherite. 
 
 Other carbonates are the Lead Carbonate, p. 152, and Copper Car- 
 bonates, p. 140, included severally under the heads of LEAD and Cop- 
 PER, on page 391, 
 
DETERMINATION OF MINERALS. 399 
 
 B. SULPHATES or SULPHIDES: Reaction for Sulphur 
 with Soda. 
 
 A. FUSIBLE; ASSAY ALKALINE AFTER FUSION. 
 
 BARITE, p. 220. H.=2°5-3'5 ; G.=43-4:72 ; trimetric ; white, ywh, 
 gyh, bluish, brown; B.B. decrepitates and fuses; flame yellow- 
 ish-green ; anhydrous. 
 
 CELESTITE, p. 222. H.—3-35; G.=8:9-3:98 ; trimetric ; white, 
 pale blue, rdh ; B.B. fuses ; flame red ; anhydrous. 
 
 ANHYDRITE, p. 211. H.=3-35; G.=2°9-30; trimetric, with 
 three rectangular and easy cleavages differing but slightly ; white, 
 bluish, gyh, rdh, red; B.B. fuses, flame reddish-yellow. 
 
 GYPSUM, p. 210. H.=1:5-2 ; G.=2'3-2°35; monoclinic, one per- 
 fect, pearly cleavage ; white, gray, but also brown, black from im- 
 ee ; B.B. yields much water, becomes white and crumbles 
 easily. 
 
 B. FUSIBLE ; REACTION FOR IRON. 
 
 COPIAPITE, p. 182. H.=15; G.=2:14; yellow; on coal, becomes 
 magnetic ; hydrous. 
 
 Haiiynite, p. 270, also gives the sulphur reaction with soda. 
 
 C. INFUSIBLE, OR NEARLY SO. 
 
 ALUMINITE, p. 199. H.=1-2; G.=1°66; adheres to the tongue; 
 white ; B.B. blue with cobalt solution. Alunite, p. 198, is similar, 
 but H.=4, and G.=2°58-2°75. 
 
 SPHALERITE, p. 154. H.=3'5-4; G.=3-9-4:2 ; isometric ; light 
 to dark resin-yellow ; B.B. on coal, coating of zine oxide. 
 
 C. ARSENATES: Arsenical fumes on coal. 
 
 SCORODITE, p. 185. H.=3'5-4; G.—3:1-3:3 ; trimetric ; leek-green 
 to liver-brown ; B.B. fuses easily, flame blue, and with soda gives 
 a magnetic bead ; on coal alliaceous fumes ; in HCl. sol. 
 
 PHARMACOSIDERITE, p. 185. H.=2:5; G.=2'9-8; cubes and 
 tetrahedrons ; dark green, bnh, reddish; B.B. same as for scorc- 
 dite. 
 
 PHARMACOLITE, p. 214. H.=2-2°5 ; G.=2°6-2°75 ; wh, gvyh, rdh ; 
 monoclinic with one eminent cleavage; B.B. fuses, flame blue; 
 on coal, alliaceous fumes; after ignition assay alkaline; in HCl 
 sol, 
 
400 DETERMINATION OF MINERALS. 
 
 D. SILICATES, PHOSPHATES, OXIDES : SPECIES NOT IN- 
 CLUDED IN THE THREE PRECEDING SUBDIVISIONS. 
 
 I. Streak deep red, yellow, brownish-yellow, green or black. 
 
 A. INFUSIBLE, OR FUSIBLE WITH MUCH DIFFICULTY. 
 
 HEMATITE, p. 176. Red to black ; streak red; B.B. reaction for 
 iron ; magnetic after ignition in R.F. ; anhydrous. 
 
 LIMONITE, ‘p. 181. Brownish and ochre-yellow to black ; streak 
 brownish-yellow ; B.B. gives off water, turns red, becomes mag- 
 netic in R.F. 
 
 TURGITE, p. 182. Brown to black; streak red; BB. gives off 
 water ; decrepitates ; becomes magnetic in R.F. 
 
 FERGUSONITE, p. 202. Brownish black ; infusible. 
 
 ZINCITE, p.155. Red; streak orange; B.B. on coal, zinc oxide 
 coating, and coating moistened with cobalt solution, green in R.F. 
 
 B. FUSIBLE WITHOUT MUCH DIFFICULTY. 
 
 WOLFRAMITE, p. 183. Grayish to brownish black ; streak dark 
 reddish brown to black ; lustre submetallic; G.=7-1-755. B.B. 
 fuses easily, and becomes magnetic ; reaction for tungsten. 
 
 VIVIANITE, p. 184. Blue to green (to white); streak bluish- 
 white ; G.—2°5-2°7; H.=1'5-2, hydrous ; B.B. fuses easily to mag- 
 netic globule, coloring flame bluish-green. 
 
 TORBERNITE, p. 170. Bright green, square tabular micaceous 
 crystals ; streak paler green ; H.=2-2°5 ; hydrous ; yields a globule 
 of copper with soda. 
 
 SAMARSKITE, p. 202. H.=55-6; G.=5-6-58; velvet-black ; 
 ‘streak dark reddish brown ; B.B. fuses on the edges. 
 
 II. Streak grayish or not colored. 
 1. INFUSIBLE. 
 
 A. GELATINIZE WITH ACID, FORMING A STIFF JELLY. 
 
 CHRYSOLITEH, p. 255. Yellow-green to olive-green, looking like 
 glass ; H.=6°7 ; G.=3'3-3'5 ; B.B. reacts for iron, becomes mag- 
 netic ; anhydrous. 
 
 CHONDRODITE, p. 281. H.=6-6'5; G.=3-1-3°25 ; pale yellow 
 to brown, and reddish-brown ; lustre vitreous to resinous ; B.B. re- 
 action for iron and fluorine ; anhydrous. 
 
 ALLOPHANE, p. 296. H.=3; G.=1:8-1:9; always amorphous, 
 never granular in texture; bluish, greenish ; B.B. infus., a blue 
 color with cobalt solution ; hydrous. 
 
 Willemite, Calamine, Sepiolite, fuse with great difficulty, and are in- 
 cluded under fusible gelatinizing species, p, 402. 
 
DETERMINATION OF MINERALS. 401 
 
 B. NOT FORMING A STIFF JELLY WITH ACID ; HYDROUS. 
 a. Blue with cobalt solution (owing to presence of aluminum), 
 
 WAVELLITE, p. 201. H. =3'25-4 ; G. =2°3-2°4; white to green, 
 brown ; B.B. bluish-green flame after moistening with sulph. acid. 
 LAZULITE, p. 199. H.=5°6; G.=3-3-1 ; blue; B.B. green flame, 
 especially after moistening with sulph. acid ; hydrous. 
 
 TURQUOIS, p. 200. H.=6; G.=2°6-2°85 ; sky-blue, pale green ; 
 B.B. flame green. 
 
 KAOLINITH, p. 810. H.—1-2; G.=2:4-2°65 ; white when pure; 
 feel greasy ; B.B. flame not green. 
 
 GIBBSITE, p. 194. H.=2°5-3'5 ; G.=2°3-2°4 ; white, grayish, green- 
 ish ; B.B. flame not green ; soluble in strong sulph. acid. 
 
 DIASPORE, p. 194. H.=6°5-7; G.=3°3-3°5 ; in thin foliated crys- 
 tals, plates or scales; white, greenish, brownish; B.B. flame not 
 green ; soluble in sulphuric acid after ignition. 
 
 b. Pale red or pink color, with cobalt solution (owing to presence of 
 magnesium), 
 
 BRUCITE, p. 204. H.=25; G.=2-3-2-45; pearly, white, green- 
 - ish; foliaveous or fibrous and flexible ; B.B. after ignition, alkaline. 
 
 c. Not blue or red with cobalt solution. 
 
 OPAL, p. 239. H.=5-5-6'5; G.=1'9-2°3; B.B. with soda soluble 
 with effervescence. 
 
 GENTHITE, p. 309. H.—3-4; G.=2-4; pale green, yellowish ; 
 B.B. with borax a violet bead, becoming gray in R.F. owing to 
 nickel ; decomp. by H Cl. 
 
 CHRYSOCOLLA, p. 142. H.—2-4; G.=2-2°24; pale bluish-green 
 to sky-blue ; B.B. flame emerald-green, and with soda on coal globule 
 of copper. 
 
 The micas, chlorites, chloritoid, and serpentine often fuse on their 
 edges with much difficulty. 
 
 C. NOT FORMING A STIFF JELLY; ANHYDROUS. H.=—5 to 9. 
 a. Blue color with cobalt solution. 
 
 CORUNDUM, p. 192. H.=9; G.=4; rhombohedral; blue, white, 
 red, gray, brown. 
 
 CHRYSOBERYL, p. 196. H.=8-5; G.=3-7; gray, green, to emo- 
 rald-green. 
 
 TOPAZ, p. 286. H.=8; G.=3°5; in rhombic prisms with perfect 
 basal cleavage, rarely columnar ; white, wine-yellow, and other 
 shades. 
 
 RUBELLITE,, p. 283. H.=7°5 ; G.=3; in prisms of 8, 6, or 9 sides ; 
 rose-red ; reaction for boron. 
 
 ANDALUSITE, p. 284. H.=7'5; G.=3°2; always in prismatic 
 crystals, often tesselated within, [/\ J=93° ; grayish-white to brown. 
 
 FIBROLITE, p. 285. H.=6-7; G.=3-2; columnar or fibrous forms 
 and prismatic crystals with brilliant diag. cleavage. 26 
 
402 DETERMINATION OF MINERALS. 
 
 CYANITE, p. 286. H.=—5-7 (greatest on extremities of crystals) ; 
 G.=3°6 ; in long or short prismatic crystallizations, often bladed 
 prisms ; pale blue to white and gray. 
 
 LEUCITE, p. 271. H.=—5'5-6 ; G.=2°5 ; white, gyh ; often in trapezo- 
 hedral crystals. 
 
 b. Not giving a blue or reddish color with cobalt solution ; = 
 8 to 5. 
 
 SPINEL, p. 194. H.=8; G.=8:5-4-1; in octahedrons of red, green- 
 ish, gray, black colors. Gahnite is similar, but with borax on coal, 
 gives reaction for zinc. 
 
 BERYL, p. 252. H.=75-8; G.=2°6-2°7; always in hexagonal 
 prisms ; pale bluish and yellowish green, to emerald-green, also 
 resin yellow and white, no distinct cleavage. 
 
 ZIRCON, p. 259. H.=7°5 ; G.=4-4°75 ; dimetric, and often in square 
 prisms ; lustre adamantine ; brown, gray. 
 
 STAUROLITH, p. 291. H.=7; G.=3-4-3'8; in prisms of 123°, 
 and often in cruciform twins; no distinct cleavage ; brown, black, 
 
 ray. 
 
 OUARTZ, p. 233. H.=%; G.=2°6; often in hexagonal crystals 
 with pyramidal terminations; of various shades of color. OPAL, 
 p. 239, is in part anhydrous. 
 
 MONAZITH, p. 203. H.=5-5:5; G.=4:9-5°3; in small brown im- 
 bedded monoclinic crystals, with perfect basal cleavage ; B.B. flame 
 bluish-green when moistened with sulph. acid. 
 
 RUTILE, p. 162. H.=6-65;. G.=4:15-4°25; dimetric; reddish- 
 brown to brownish-red, green, black; B.B. reaction for titanium. 
 BROOKITE and OCTAHEDRITE, p. 163, are similar, except in crystal- 
 line forms, and G. in brookite 4'0-4°'25, in octahedrite 8°8-3'95. 
 
 PHROFSKITE, p. 163. H.=5°5; G.=4-41; yellowish, brown, 
 black ; cubic and octahedral forms ; B.B. reaction for titanic acid. 
 
 ENSTATITE, p. 244. H.=5°5 ; G.=3'1-3°3 ; in prismatic and fibrous 
 forms with JA J=88° 16’, also foliated ; whitish, grayish, brown. 
 Anthophyllite is similar, but IA J=125°, and it fuses on the edges 
 with great difficulty. 
 
 Iolite, apatite, scheelite, euclase, fuse with much difficulty, and 
 euclase gives some water in closed tube when highly ignited. 
 
 9. FUSIBLE WITH LITTLE OR MUCH DIFFICULTY. 
 A. Gelatinize and afford a Stiff Jelly. 
 
 a. Hydrous; fuse easily. 
 
 DATOLITEH, p. 289. H.=5-5°5; G.=2°8-3; white, greenish, yel- 
 lowish ; crystals glassy, stout, sometimes massive and porcellanous, 
 never fibrous ; B.B. fuses easily, reaction for boron. 
 
 NATROLITE, p. 299. H.=5-5'5 ; G.=2°3-2-4; in slender rhombic 
 prisms, and divergent columnar ;. white, ywh, rdh, red; B.B. fuses 
 very easily. 
 
 SCOLECITE, p. 299. H.=5-5:5; G.=2°16-2°4; cryst. much like 
 
DETERMINATION OF MINERALS. . 403 
 
 natrolite, but twinned, with converging striz on 7-7 as in figure on 
 p. 299; B.B. sometimes curls up, fuses very easily. 
 
 GiM[ELINITE, p. 301. H.=45; G.=2-2-2; in small and short hex- 
 agonal or rhombohedral cryst. ; B.B. fuses easily. 
 
 PHILIPPSITEH, p. 302. H.=4-4:5; G.=2-2 ; intwinned crystals ; 
 B.B. fuses rather easily. 
 
 LAUMONTITE, p. 293. H.=3:5-4; G.=2:2-2:'4; white, reddish ; 
 crystals become white and crumbling on exposure to the air; B.B. 
 fuses rather easily, 
 
 Pectolite (p. 293), and Analcite (p. 299), imperfectly gelatinize. 
 
 b. Hydrous; fuse with much difficulty. 
 
 CALAMINE, p. 157. H.=4:5-5; G.—3-15-3:19 ; white, greenish, 
 bluish ; orthorhombic in crystals BB. fus. with great difficulty, re- 
 action for zinc and none for iron ; hydrous. 
 
 SEPIOLITE, p. 306. White ; soft and almost clay-like, also fibrous ; 
 B.B. fuses with difficulty, with cobalt solution reddish ; hydrous. 
 PYROSCLERITE, p. 317. H.=3; G.=2°74; micaceous ; B.B. fuses 
 
 on thin edges. 
 
 c. Anhydrous. 
 a No REACTION FOR SULPHUR ; NO COATING ON COAL. 
 
 NEPHELITE, p. 269. H.—55-6 ; G.—2'5-2:65; hexagonal prisms 
 and massive ; vitreous, with greasy lustre ; white, ywh, gyh brown, 
 rdh ; B.B. fuses rather easily. 
 
 WOLLASTONITEH, p. 244. H.=—45-5; G.=—2-75-2:9; white, gyh, 
 rdh, bnh; B.B. fuses easily. 
 
 SODALITEH, p. 270. H.=—5:5-6; G.=—2-18-2:'4; white, blue, red- 
 dish ; in dodecahedrons and massive ; B.B. fuses not very easily. 
 WILLEMITE, p. 157. H.=—55; G.—3-9-4'3; white to greenish, 
 reddish, brownish; B.B. glows and fuses with difficulty ; reaction 
 
 for zinc and none for iron ; anhydrous. 
 
 fs. REACTION FOR SULPHUR B.B. WITH SODA. 
 
 HAUYNITE, p. 270. H.=5°5-6; G.=2°4-2'5; blue, greenish ; iso- 
 metric, in dodecahedrons, octahedrons ; B.B. fuses with some diffi- 
 culty. 
 
 DANALITE, p. 256. H.—5 5-6; G.=3-427 ; isometric; flesh-red to 
 gray ; B.B. fuses rather easily, and gives reaction for manganese 
 and zinc. 
 
 B. Not Gelatinizing. 
 
 1. STRUCTURE EMINENTLY MICACEOUS, SURFACE OF FOLIA 
 MORE OR LESS PEARLY; H. OF SURFACE OF FOLIA 
 NOT OVER 3°53; ANHYDROUS OR HYDROUS. 
 
 MUSCOVITH, BIOTITH, PHLOGOPITEH, LEPIDOLITE, LE- 
 PIDOMELANE : for distinctions see pp. 266-268. Anhydrous, 
 
404 DETERMINATION OF MINERALS. 
 
 or affording very little water; B.B. fuse with difficulty on thin 
 edges, excepting lepidomelane which fuses rather more easily. 
 
 MARGARODITE, DAMOURITE, p. 313. Much like common 
 mica, but more pearly and greasy to the feel, folia not elastic ; giv- 
 ing a little water in the closed tube ; color usually whitish. 
 
 PENNINITE, RIPIDOLITE, PROCHLORITE, p. 318. Usually 
 bright or deep green, blackish-greer, reddish, rarely white ; folia . 
 tough, inelastic; B.B. diff. fus., reaction for iron and yield much 
 water ; partially decomposed by acids. 
 
 VERMICULITE, JEFFERISITE, p. 317. Brown, yellowish-brown, 
 
 reen ; exfoliate remarkably ; yield much water. 
 
 MARGARITE, p. 319. H.=3'5-4'5 (highest on edges) ; G.=2°99 ; 
 white, ywh, rdh ; folia somewhat brittle ; B.B. fuses on thin edges ; 
 yields a little water. 
 
 TALC, p. 304. H.=1-1%5; G.=2°5-2°8; pearly and very greasy to 
 the touch; white, pale green, gray; B.B. very difficultly fusible, 
 yields usually traces of water ; reddish with cobalt solution. 
 
 PYROPHYLLITE, p. 306. Similar to tale; but B.B. exfoliates 
 remarkably ; blue with cobalt solution. 
 
 FAHLUNITH, p. 314, has often a more or less distinct micaceous 
 structure. 
 
 Autunite, p. 170, has a mica-like basal cleavage ; but it occurs 
 in small square tables of a bright yellow color. Diallage, p. 246, 
 has a structure nearly micaceous. Serpentine is sometimes nearly 
 micaceous, but the folia are not easily separable and are brittle. 
 Chloritoid has a perfect basal cleavage, but folia very brittle, and 
 cleavage less easily obtained than in the preceding ; and moreover the 
 mineral is infusible. . 
 
 9. SrRUCTURE NOT MICACEOUS. 
 
 a. Hydrous. 
 a. NO REACTION FOR PHOSPHORUS, OR BORON. 
 
 + Hardness, with the exception of a variety of serpentine, 1to3> 
 lustre not at all vitreous. 
 
 CHLORITES, p. 318. H.=2-25. Here fall the massive granular 
 chlorites, olive-green to black in color, of the species penninite, ri- 
 pidolite, prochlorite ; B.B. reaction for iron, fuses with difficulty ; 
 yields much water. 
 
 VERMICULITE, p. 317. H.=1-1'5. Granular massive forms of 
 vermiculite. 
 
 TALC, p. 304. .H.=1-1'5. Here falls steatite (soapstone) or massive 
 talc, of white to grayish green and dark green color, granular to 
 cryptocrystalline in texture. B.B. fuses with great difficulty, and 
 yields only traces of water ; no reaction for iron, or only slight. 
 
 PYROPHYLLITBE, p. 306. Grayish white, massive or slaty; B.B. 
 like the crystallized, p. 408, in its difficult fusibility and little water 
 
 ielded, but does not exfoliate. 
 
 SHRPENTINE, p. 307. H.=2°5-4; G. —2:36-2°55 ;_ olive-green ; 
 ywh green; blackish green, white; B.B. fuses with difficulty on 
 thin edges ; yields much water. 
 
DETERMINATION OF MINERALS. 405 
 
 PINITE, p. 812. H.=2'5-3:5; G.=2-6-2°85; lustre feebly waxy; 
 gray, gnh, bnh. B.B. fuses; yields water. 
 
 DAMOURITE, p. 313. Same as crystallized, p. 403, but in mas- 
 Sive aggregation of scales. 
 
 tt Hardness 3°5 to 6'5; lustre often pearly on a cleavage surface, 
 but elsewhere vitreous, 
 
 PREANITE, p. 295. H.=6-6'5; G.=2'8-3; pale green to white; 
 crystals often barrel-shaped, made of grouped tables; B.B. fuses 
 very easily ; decomp. by HCl. 
 
 PECTOLITE, p. 298. H.=5 ; G.=2-68-2'8 ; white ; divergent fibrous, 
 or acicular; B.B. fuses very easily; gelatinizes imperfectly with 
 HCl. , 
 
 APOPHYLLITE, p. 294. H.=4:5-5 ; G.=2°3-2:4 ; white, gnh, ywh, 
 rdh ; dimetric, one perfect pearly cleavage transverse to prism; 
 B.B. fuses very easily ; a fluorine reaction ; decomp. by H Cl. 
 
 CHABAZITE, p. 300. H.=4-5; G.=2-2:2; rhombohedral, vitreous ; 
 white, rdh ; B.B. fuses easily ; decomp. by HCl. 
 
 HARMOTOME, p. 301. H.=45; G.=2:44; white, ywh, rdh; 
 crystals twins, usually cruciform ; B.B. fuses not very easily ; vitre- 
 ous in lustre ; decomp. by HCl. 
 
 STILBITE, p. 302. H.=35-4; G.=2-2:2; white, ywh, red; crys- 
 tallizations often radiated-lamellar; one perfect pearly cleavage ; 
 B.B. exfoliates, fuses easily ; decomp. by H Cl. 
 
 HEULANDITE, p. 303. H.=8°5-4; G.=2-2; in oblique crystals, 
 with one perfect pearly cleavage ; B.B. same as for stilbite. 
 
 HUCLASE, p. 288. H.=7-5; G.=8-1: in glassy transparent mono- 
 clinic crystals; B.B. fuses with great difficulty; gives water in 
 closed tube when strongly ignited. 
 
 Prehnite, apophyllite, chabazite, harmotome, heulandite, and euclase 
 never occur in fibrous forms. 
 
 fi. REACTION EITHER FOR PHOSPHORUS OR BORON. 
 
 VIVIANITE, p. 184. H.=15-2; G@.=2-55-7; monoclinic with one 
 perfect cleavage ; white, blue, green; B.B. fuses very easily, the 
 flame bluish green, a gray magnetic globule ; in HCl sol. 
 
 ULEXITE, p. 212. H.=1; G.=1°65; white, silky, in fine fibres; 
 B.B. fuses very easily, and moistened with sulph. acid flame for an 
 instant green, owing to the boron present ; little sol. in hot water. 
 PRICEITE (p. 212) is in texture and color like chalk; similar to 
 ulexite in green flame B.B. 
 
 Borax and Sassolite are other soft minerals containing boron, but 
 these have taste. 
 
 6b. Anhydrous. 
 a, B.B. the flame lithium-red. 
 SPODUMENE,, p. 248. H.=65-7; G.=313-3-19; white, gyh, gnh 
 
 white, monoclinic (like pyroxene), with [A J=87°, and perfect 
 cleavage parallel to J and 7-7 ; B.B. swells and fuses, 
 
406 DETERMINATION OF MINERALS. 
 
 PETALITH, p. 248. H.=6-65; G.=2°42°0; white, gray, rdh, 
 gnh ; B.B. becomes glassy and fuses only on the edges. 
 
 HHBRONITE, AMBLYGONITE, p. 199. H.=6; G.=3-3'1 ; moun- 
 tain green, gyh, white, bnh; B.B. fuses very easily, reaction for 
 fluorine. 
 
 TRIPHYLITH, p. 190. H.=5; G.=35-36; greenish gray, bluish, 
 often bnh black externally ; B.B. fuses very easily, globule mag- 
 netic ; with soda, manganese reaction. 
 
 LEPIDOLITE, p. 268. H.=2'5-4; G.=2°8-8 ; micaceous, also scaly- 
 granular; rose-red, pale violet, white, gyh; B.B. fuses easily ; 
 after fusion gelat. with HCl. Some biotite, p. 266, gives the lithia 
 reaction. 
 
 p . B.B. boron reaction (green flame). 
 
 TOURMALINE, p. 282. H.=7; G.=2°9-3°3 ; rhombohedral, prisms 
 with 3, 6, 9 sides, no longitudinal or other distinct cleavage ; black, 
 blue black, green, red, rarely white ; lustre of dark var. resinous ; 
 B.B. fusion easy for dark var. and diff. for light. 
 
 AXINITE, p. 264. H.=6°5-7; G.=3°27; triclinic, sharp-edged, glassy 
 crystals ; rich brown to pale brown and grayish ; B.B. fuses readily ; 
 with borax violet bead. 
 
 BORACITE, p. 206. H.=7; G.=2°97; isometric ; white, gyh, gnh; 
 lustre vitreous ; fuses easily, coloring flame green. 
 
 Danburite, p. 264, is another boron silicate. 
 
 y. B.B. reaction for titanium. 
 
 TITANITEH, p. 290. H.=5-5:5; G.—3°4-3'56 ; monoclinic ; usually 
 in thin sharp-edged crystals ; brown, ywh, pale green, black ; 
 lustre usually subresinous ; B.B. fuses with intumescence. 
 
 6. Reaction for fluorine or phosphorus. 
 
 CRYOLITH, p. 197. H.=2°5; G.—2'9-8 ; white, rdh, bnh ; fuses in 
 
 the flame of a candle ; soluble in sulph. acid which drives off hydro- 
 en fluoride, a gas that corrodes glass. , 
 
 FLUORITE, p. 208. H.=4; G. =3-3°25; isometric, with perfect 
 octahedral cleavage, and massive ; white, wine-yellow, green, pur- 
 ple, rose-red, and other bright tints ; phosphoresces ; when heated, 
 decrepitates ; B.B. fuses, coloring the flame red; after ignition, 
 alkaline. 
 
 Lepidolite (p. 268), Amblygonite (p. 199), also give a fluorine re- 
 action. 
 
 APATITH, p. 212. H.=4'5-5; G. —2°9-3'25 ; often in hexagonal 
 prisms ; pale green, bluish, yellow, rdh, buh, pale violet, white ; 
 B.B. fuses with difficulty, moistened with sulph. acid and heated, 
 flame bluish green from presence of phosphorus ; sometimes reaction 
 for fluorine. 
 
 €, Reaction for iron. 
 
 GARNET, p. 256. H.=6°5-7°5 ; G.—3'15-4°3 ; isometric, usually in 
 dodecahedrons and trapezohedrons, also massive, never fibrous or 
 columnar ; red, bnh red, black, cinnamon- red, pale green, to emerald- 
 
DETERMINATION OF MINERALS. 407 
 
 green, white. B.B. dark-colored varieties fuse easily, and give iron 
 reaction, but emerald-green var. almest infusible ; a white to yellow 
 massive garnet is hardly determinable without chemical analysis. 
 
 VESUVIANITE (Idocrase), p. 261. H.=6°'5 ; G.=8°35-8-45 ; dimetric 
 and often in prisms of four or eight sides, never fibrous ; brown to 
 pale green, ywh, bk; B.B. fuses more easily than garnet ; reaction 
 for iron. 
 
 EPIDOTE, p. 262. H.—6-7; G.=8-25-38'5; in monoclinic cryst. 
 and massive, rarely fibrous ; unlike amphibole in having but one 
 cleavage direction ; ywh green, bnh green, black, rdh, yellow, dark 
 gray ; B.B. fuses with intumescence. 
 
 AMPHIBOLBE, dark varieties including hornblende, actinolite, and 
 other green to gray and black kinds, p. 249. H.=&6; G.=8-3°4; 
 monoclinic, in short or long prisms, often long fibrous, lamellar, and 
 massive, prisms usually four or six sides, [/ /=124}", cleavage par. 
 to J; B.B. fusion easy to moderately difficult. 
 
 ANTHOPHYLLITE, p. 252, like hornblende; bnh gray to bnh 
 green, sometimes lustre metalloidal; B.B. fuses with great difti- 
 culty. 
 
 PYROXENE, augite, and all green to black varieties, p. 245. 
 H.=5-6 ; G.=38'2-3'5 ; monoclinic, in short or oblong prisms, lamel- 
 lar, columnar, not often long, fibrous or asbestiform, prisms usually 
 with four or eight sides, 7\ J=87° 5’, cleavage par. tol; B.B. as 
 in hornblende. 
 
 HYPERSTHENE, p. 244. H.=—5-6; G.=8'89; cryst. nearly as in 
 pyroxene, but trimetric, usually foliated massive, also fibrous ; bnh 
 green, gyh black, pinchbeck-brown ; B.B. fuses with more or less 
 difficulty. Bronzite, p. 244, is similar and almost infusible. 
 
 IOLITE, p. 264. H.=7-7'°5 ; G.=—2-6-2°7 ; blue to blue violet ; looks 
 like violet-blue glass ; B.B. fuses with much difficulty. 
 
 Tourmaline, much Titanite, and Jlvaite (p. 263), B.B. give iron re- 
 action, 
 
 €. No reaction for iron. 
 
 SCHEBELITE, p. 212. H.=4:5-5; G.=—5-9-6:1; ywh, gnh, rdh, pale 
 yellow ; lustre vitreous-adamantine ; fuses on the edges with great 
 difficulty. 
 
 SCAPOLITES, p. 268. H.=5°5-6; G.=2°6-2°74; dimetric, often 
 in square prisms ; white, gray, gnh gray ; B.B, fuses easily with in- 
 tumescence. 
 
 ZOISITH, p. 263. H.=6-6'5 ; G.=3'1-3-4; trimetric, oblong prisms 
 and lamellar massive, cleavage in only one direction. 
 
 AMPHIBOLE, white var. (tremolite), p. 249. Same as for other 
 amphibole (above), except in color ; B.B. fuses. 
 
 PYROXENE, wihite var., p. 215. Same as for other pyroxene (above), 
 except in color ; B.B. fuses. ; 
 
 ORTHOCLASE, p. 278. H.=6-6°5; G.=2°4-2°62 ; monoclinic, stout 
 cryst., and massive, never columnar, two unequal cleavages, the 
 planes at right angles with one another, and cleavage surfaces never 
 finely striated, as seen under a pocket lens or microscope ; white, 
 gray, flesh-red, bluish, green; B.B. fuses with some difficulty. 
 
408 DETERMINATICN OF MINERALS. 
 
 ALBITE, p. 277, OLIGOCLASE, p. 276. H.—6; G. =2°56-2°72 ; 
 triclinic, but cryst. as in orthoclase, except that the two cleavage 
 planes make an angle of 934° to 94°, and one of them has the surface 
 striated ; white usually, flesh-red, bluish ; B.B. fuse with a little 
 difficulty ; not acted on by acids. 
 
 LABRADORITE, p. 276. H.=6 ; G.=2°66-2°%6 ; triclinic, like albite 
 in cryst., and nearly in cleavage angle, 93° 20’, and in strie of 
 surface; white, flesh-red, bnh red, dark gray, gyh brown; B.B. 
 fuses easily ; decomposed by HCl with difficulty. 
 
 ANORTHITE, p. 275. H.=6-7; G.=2°66-2°78; cryst. and strie 
 as in albite, cleavage angle 94° 10' ; white, gyh, rdh; B.B, fusion 
 difficult ; decomposed by HCl with separation of gelat. silica. 
 
 MICROCLINE, p. 278. Very near orthoclase in all characters, but 
 triclinic, cleavage angle differing only 16’ from a right angle, and 
 surface of most perfect cleavage striated, but strize exceedingly 
 fine, often difficult to detect with a good pocket lens, and requiring 
 the aid of a polariscope ; color white, gray, flesh-red, often green. 
 
 For optical distinctions of FELDSPARS, see p. 274. 
 
 EBUCLASE, p. 288. H.=75; G.=8'1; in monoclinic crystals, with 
 one perfect diagonal cleavage; pale green to white, bnh, trans- 
 parent ; becomes electric by friction. 
 
ON ROCKS. 
 
 I. CONSTITUENTS OF ROCKS. 
 
 Rocks are made up of minerals. <A few kinds consist of 
 a single mineral alone: as, for example, /imestone, which 
 may be. either the species calcite or dolomite ; gwartzyte 
 (along with much sandstone), which is quartz; and felsy/e, 
 which is orthoclase. But even these simple kinds are sel- 
 dom free from other ingredients, and often contain visibly 
 other minerals. Nearly all kinds of rocks are combinations 
 of two or more minerals. They are not definite compounds, 
 but indefinite mixtures, and hardly less indefinite than the 
 mud of a mud-flat. The limits between kinds of rocks 
 are consequently ill-defined. Granite graduates insensibly 
 into gneiss, and gneiss as insensibly into mica schist and 
 quartzyte, syenyte into granite, mica schist into hornblende 
 schist, granite also into a compact porphyry-like rock, and 
 trachyte; and so it is with many other kinds. The fact 
 is a chief source of the difficulty in studying and defining 
 rocks, and especially the crystalline kinds. The different 
 rocks are not species in the sense in which this word is used 
 in science, but only kinds of rocks. 
 
 The minerals which are the chief constituents of rocks 
 are of two classes: (A) the Siliceous; (B) the Calcareous. 
 
 A. The siliceous are as follows : 
 
 1. Quartz, which probably makes up one-third of the 
 rocky material of the crust of the globe. 
 
 2. The Feldspars (p. 272); of which orthoclase (with 
 microcline) is most abundant; next to it, oligoclase and 
 labradorite ; and next albite, andesite, and anorthite. 
 
 3. The Micas (p. 265): muscovite and biotite, of equal 
 prominence, the others much less common. 
 
 4. Amphibole and Pyroxzene species (p. 245, and beyond) : 
 especially hornblende or black amphibole, and augite or 
 
 409 
 
410 DESCRIPTIONS OF ROCKS. 
 
 black pyroxene 3 also the green hornblende or actinolite; the 
 green foliated hornblende called smaragdite, and the foli- 
 ated pyroxene sometimes wrongly called hypersthene, and 
 another variety called diallage; also occasionally the species 
 hypersthene and enstatite. 
 
 5. The Feldspar-like minerals, nephelite (p. 269) and leu- 
 cite (p. 271), which are related in constituents and quan- 
 tivalent ratios to the feldspars, alumina being the only ses- 
 quioxide base, and lime, potash, and soda the protoxide bases 
 afforded in analyses; the atomic ratios for the protoxides, 
 sesquioxide, and silica being in nephelite, 1:3: 4, as in 
 anorthite; and in leucite 1:3: 8, as in andesite. Also, less 
 abundantly, Sodalite (p. 270), which has essentially the 
 ratio of anorthite and nephelite. 
 
 6. Minerals of the Saussurite group. These jade-like 
 species differ from the feldspars—(1) in being always fine- 
 granular in texture; (2) in having a high density, G.= 
 2°9-3:4; in varying from the feldspar type chemically. 
 They are near some soda-lime feldspars in constituents, but 
 not always in the atomic relations of the constituents, nor 
 in the absence uniformly of magnesia. There are two 
 prominent kinds. One is between anorthite and zoisite in 
 composition (see p. 263); yet, unlike these minerals, its 
 analyses afford several per cent. of soda and some magnesia. 
 The second approaches labradorite ; Delesse obtained for a 
 specimen from Mt. Genévre (Alps), Silica 49°73, alumina 
 29°65, iron protoxide 0°85, magnesia 0°56, lime 11:18, soda 
 4:04, potash 0°24, water (with a little CO,) 3°75; and a 
 Silesian specimen afforded Vom Rath nearly the same result. 
 A third kind from Corsica, according to Boulanger’s analy- 
 sis, has nearly the same composition as zoisite. <A fourth 
 is jadeite (p. 263), a stone occurring in the Swiss lake-dwell- 
 ings—but not yet found in the saussurite rocks of Switzer- 
 land. 
 
 The saussurite of Siberia and the Alps has been observed 
 to have sometimes the form of twins of a triclinic feldspar. 
 This, and the texture, density, and composition, show that 
 saussurite is, in part at least, pseudomorphous, and, in some 
 regions, after labradorite. By some peculiar conditions in 
 the process of metamorphism—perhaps long-continued heat 
 with an unusual amount of moisture—the feldspar crystal- 
 lizations that formed in the incipient stages of the process 
 were afterward changed to a species of higher density and 
 
DESCRIPTIONS OF ROCKS. 411 
 
 different molecular nature ; in other words, to saussurite. 
 Some of the material appears to be still labradorite. 
 
 @ The iron-bearing minerals, Epidote (p. 262), Garnet 
 (p. 256), Chrysolite (p. 255), which characterize some varie- 
 ties of rocks. 
 
 B. The calcareous species are calcite or calcium carbonate 
 (p. 215), in various states of impurity ; and dolomite or cal- 
 clum-magnesium carbonate (p. 219), which in its rock-form 
 1s undistinguishable in external aspect from calcite. 
 
 Gypsum, or hydrous calcium sulphate, is also a consti- 
 tuent of beds among rocks, and should have its place in the 
 
 hist, although not strictly embraced under the term calca- 
 reous. 
 
 Of the siliceous minerals, orthoclase (with microcline), 
 and the two micas, muscovite and biotite, are related in com- 
 position, in that each affords 10 per cent. or more of pot- 
 ash. Leucite is another allied potash-alumina silicate, even 
 richer in potash than orthoclase, it containing 17 to 21 per 
 cent. ‘The rocks characterized by these minerals are hence 
 rich in potash. 
 
 Albite and oligoclase, and also sodalite, afford much soda, 
 the first two usually 8 to 12 per cent., and sodalite, 20 to 
 2) per.cent. Nephelite (eleolite) is also a soda mineral 
 related to the feldspars ; but, with 15 to 16 per cent. of soda, 
 there are 5 or 6 of potash ; rarely the alkali afforded is all 
 soda. 
 
 The ordinary kinds of hornblende and pyroxene, on the 
 contrary, afford little or no soda or potash. They thus dif- 
 fer widely from the potash and soda species just mentioned, 
 and naturally characterize for the most part a distinct series 
 of rocks. 
 
 Much importance has been allowed in lithology to the 
 distinction of foliated under the species hornblende and 
 pyroxene ; when, in fact, neither in mineralogy, as all 
 treatises admit, nor in lithology, has it more than a very 
 subordinate value. The character obtained this distinction 
 before it was fully understood that the foliated forms were 
 identical in composition with those in crystals or in massive 
 forms. 
 
 Hornblende does not differ from augite in composition ; 
 but since the difference in crystallization is connected with 
 a difference in the physical conditions attending their origin, 
 
412 DESCRIPTIONS OF ROCKS. 
 
 and since rocks of each kind often have a vast extent over 
 the earth’s surface, the distinction as to whether a rock is 
 hornblendic or augitic is of prominent geological interest. 
 
 II. CLASSES OF ROCKS. 
 
 Rocks are of different classes, according to their texture 
 and origin. 
 
 1. FRAGMENTAL. A large part of common rocks were 
 formed of sand, or pebbles and sand, and are only consoli- 
 dated sand-beds or gravel-beds ; and other related kinds are 
 more or less consolidated mud-beds or clay-beds. The mud- 
 beds of an estuary, or of the shallow seas off a coast, and the 
 stratified sand and gravel accumulations of sea-shores and 
 valley formations, are precisely the kind of material which 
 by consolidation have made the fragmental rocks, the most 
 abundant rocks of the earth’s surface. Each pebble, grain 
 of sand, and constituent particle of the mud, was derived 
 from preéxisting rocks, and is either an actual fragment from 
 those rocks, or else a fragment altered by more or less com- 
 plete decomposition. The rocks are hence called fragmen- 
 tal. The pebbles, and often the sands, have a worn surface, 
 and this fact, together with the structure of the beds, affords 
 evidence that they are fragmental. They are also the sedi- 
 mentary rocks of geology; for the material was for the 
 most part carried and dropped by waters as sediment. is 
 carried and dropped—the waters mainly of the ocean which 
 then covered the continents. : 
 
 2, CRYSTALLINE. Other rocks are crystalline. The grains 
 are angular instead of worn, and they crowd upon or pene- 
 trate one another because made in one process of crystal- 
 lization. They are generally angular over a fractured sur- 
 face because of the cleavage planes, like the grains of a 
 surface of broken iron. Granite, trap, white marble are ex- 
 amples of crystalline rocks. When such a rock is distinctly 
 granular there is little difficulty in deciding upon its being 
 a crystalline rock. If too fine-grained for a positive conclu- 
 sion with the aid of a pocket-lens, the doubt may usually 
 be removed by tracing it along to places where it is coarser ; 
 and if none such offers, by the preparation of thin slices for 
 microscopic examination. 
 
 Crystalline rocks have received their crystalline texture 
 in different ways. 
 
DESCRIPTIONS OF ROCKS. 413 
 
 A. By cooling from fusion. The rocks thus made are called 
 Ia@NEOUSs or ERuUPTIVE rocks, as, for example, lavas or vol- 
 canic ejections, and all rocks that, like trap, have come up 
 melted through fissures in the earth’s rocky crust. The 
 depth of the liquid source of such eruptions is unknown. 
 The fact that, at one epoch, material of the same kind has 
 sometimes been ejected at intervals along a band of country 
 a thousand miles in length, from northeast to southwest, as 
 on the Atlantic coast from Nova Scotia to South Carolina, 
 indicates considerable depth in such cases. ‘They may be 
 older rocks melted over and thrust up to the surface ; but if 
 so, the remelted rocks were in many cases those situated deep 
 in the earth’s crust, far below all the strata of its surface. 
 
 B. By subjection to long-continued heat without fusion, 
 making METAMORPHIC rocks. Through this means fragmen- 
 tal or sedimentary strata, over areas of thousands of square 
 miles, and many thousands of feet in depth, have been 
 simultaneously crystallized, turning the beds that were 
 originally made from sand, gravel, or mud, into granite, 
 gneiss, and other related rocks, and compact limestones 
 into marble. The rocks at the time of the change were 
 generally undergoing extensive mountain-making uplifts, 
 and it is supposed that the friction attending the movements 
 of the strata may have been an important source of heat for 
 the change or crystallization ; and that the diffusion of this 
 heat was due to the moisture which abounds in unaltered 
 sedimentary beds. Metamorphic strata retain their former 
 relative order of superposition, having been erystallized im 
 place, that is, without fusion. Where granite has been the 
 result, it is probable that the material was sometimes re- 
 duced to a pasty state, so that all lines of the original bed- 
 ding were obliterated ; but even in that case, the granite 1s 
 generally in the place occupied by the material before crys-" 
 tallization. In other cases, including that of some granites, 
 there was not even this degree of approach toward the origi- 
 nal condition of the true eruptive rock. During the upturn- 
 ing, the rocks were much fractured, and the fissures so made 
 became filled with the materials of the adjoining or subjacent 
 rocks, through the aid of the heated moisture present, mak- 
 ing veins ; and such veins differ widely from those, called 
 dikes, that were made when the fractures descended to re- 
 gions of melted rock, so that the fissures became filled with 
 ejected material. 
 
414 DESCRIPTIONS OF ROCKS. 
 
 Rocks thus metamorphosed or rendered crystalline are 
 distinguished as metamorphic rocks. 
 
 C. By chemical deposition. Waters often hold calcareous 
 material in solution. When carbonic acid (carbon dioxide) 
 is present in any waters, those waters will take up calcium 
 carbonate, and make calcium bicarbonate; and when the 
 waters evaporate, the calcium carbonate is deposited. This’ 
 is the process by which stalactites and stalagmites (p. 216) 
 have been made, and so also calcareous tufa and travertine 
 (p. 432). The Gardiner River region in the Yellowstone 
 Park is noted for its deposits of travertine. 
 
 In geyser regions there are siliceous deposits made by the 
 hot waters, as stated on page 240; and these also are exem- 
 plified in the Yellowstone Park. 
 
 Beds of tripolite (p. 241) sometimes become consolidated | 
 and converted into chert by the waters that penetrate them 
 these waters containing a trace of alkali or enough to 
 enable them to dissolve some of the tripoli silica, and then 
 a deposition taking place causing consolidation. The flint 
 and chert of the rocks has probably had generally this ori- 
 gin. 
 
 3. CALCAREOUS Rocxs or LimEsTONES. Compact lime- 
 stones are commonly of fragmental origin. They have been 
 made mainly out of worn or ground-up shells, corals, and like 
 calcareous material of organic origin—the movements of the 
 ocean having been, and still being, the grinding agency. 
 They were consolidated through the ocean’s waters which 
 penetrated the beds taking up a little calcareous material, 
 and then depositing it again. It is, in one sense, metamor- 
 phism. But when such compact limestones experience true 
 metamorphism, at the same time with other strata, they be- 
 come distinctly crystalline-granular, and often very coarsely 
 so, making crystalline limestone or marble. 
 
 Ill. ON SOME CHARACTERISTICS OF ROCKS. 
 
 1. CRYSTALLINE TEXTURE. Crystalline texture varies in 
 coarseness from that in which crystalline grains are visible 
 only under high magnifying power, and the rock is as apha- 
 nitic (p. 60) as flint, to that in which they are very coarse. 
 Not unfrequently one of the minerals appears in large crys- 
 tals, distributed through the mass—the mass being made of 
 
DESCRIPTIONS OF ROCKS. 415 
 
 the rest of the material in a comparatively fine-grained con- 
 dition. The porphyry of the ancients was arock of dark 
 feldspathic base, sprinkled all through with lght-colored 
 feldspar crystals; and, from this fact, any metamorphic or 
 igneous rock containing such disseminated crystals of a 
 feldspar is said to be porphyritic. 
 
 The following figures illustrate three varieties of porphy- 
 ritic rock. The first represents a specimen of the red an- 
 tique porphyry of Egypt—now often called Rosso antico— 
 the rock which gave the name porphyry to geology, a kind 
 
 2. 3. 
 
 tp, ih 
 Wl 
 
 
 
 
 
 NAT, 
 Pine 
 
 
 
 SS 
 = 
 
 
 
 
 
 iy He 
 bit, 
 
 
 
 Ly 
 
 
 
 
 
 
 
 gy 
 
 
 
 
 if oa 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 WU 
 f 
 
 Myf Wy f 
 
 Vy, ig tl 
 
 My hi 4 
 
 Witt Y 4 
 
 i iy 
 Yi) VN A 
 
 / Wf AEH | i. H 
 Li Ls li 
 
 fp 
 HL, 
 
 ij 
 Rosso Antico. Oriental Verd-antique. Porphyritic gneiss. 
 
 much used by the Romans (though not by the Greeks or 
 Egyptians), and quarried by them in the mountain Djebel- 
 Dokhan, twenty-five miles from the Red Sea, in latitude 
 27° 20'. Through the red aphanitic base small whitish 
 crystals of orthoclase are thickly distributed. Figure 2 1s 
 from a polished piece of green antique poryphyry. The 
 feldspar crystals are comparatively large, and the compact 
 base has a dark green color. Figure 3 represents a large 
 crystal of orthoclase with the gneiss about it, from porphy- 
 ritic gneiss. The feldspar crystals in porphyritic gneiss or 
 granite sometimes measure three inches by one and a half, 
 and again only a fraction of an inch. These orthoclase 
 crystals, as often in other porphyritic rocks, are twin crys- 
 tals, the plane of cleavage of one half making an angle of 
 52° 23’ with that of the other half. Occasionally large crys- 
 
416 DESCRIPTIONS OF ROCKS. 
 
 tals contain small crystals of mica distributed in one or 
 more layers concentric with the sides. 
 
 The degree of coarseness in the texture of a crystalline 
 rock has been determined chiefly by the rate of cooling, 
 in connection with the nature of the material. Relatively 
 rapid cooling produces a fine texture or grain, and very slow 
 cooling a coarser. 
 
 A melted rock may cool too rapidly to become stony - 
 throughout, or to become stone at all; and, in the latter 
 case, the material made is glass. Common melted glass 
 would be stone on cooling if the process were gradual 
 enough. 
 
 Figures 4 to 6 represent much-magnified views afforded 
 by transparent slices from glassy rocks, in three of their 
 stages between the pure glassy and the true stony state. In 
 4, from obsidian, or volcanic glass, of Greenland, there 
 are radiating clusters consisting of hair-like mzcrolites (or 
 microscopic minerals), called trichites (from the Greek thriz, 
 hair), such as are common in all obsidians. Fig. 5 shows 
 the texture of a variety of pearlite, a light gray rock of 
 
 
 
 Fr S os 
 
 Trichites in ob- Trichites and Fluidal Microlites ina Pitchstone 
 sidian. texture in Pearlite. from Weisselberg. 
 
 pearly lustre from the Montezuma Range in the Nevada 
 Basin, as figured by Zirkel; in this, trichite clusters, besides 
 being very numerous, are arranged in lines or planes, and 
 some of the trichites are powdered with pellucid grains, or 
 globulites, which are incipient crystals. Zirkel represents 
 another kind in which the radiating trichites are each a 
 string of globulites. Fig. 6 represents a pitchstone from 
 
DESCRIPTIONS OF ROCKS. 417 
 
 ~ 
 
 Weisselberg (from Rosenbusch), in which the microlites are 
 distinctly crystalline in form, and some give evidence that 
 they are feldspar crystals, others that they are augite and 
 magnetite, and indicate that the rock is intermediate be- 
 tween a glass and a doleryte. Thus there is a passage to 
 ordinary stone. ‘Trap or doleryte has been used for making 
 bottle-glass ; and attempts have been made to manufacture 
 glass directly from a variety of granite containing little 
 quartz. 
 
 Eruptive rocks, that have come up through fissures, 
 often have glassy particles among the stony in the part 
 near the walls of the fissure when not so through the inte- 
 rior of the mass; and many such rocks, covering large areas, 
 have glassy grains among the stony grains, or a glassy mag- 
 mi, because the cooling generally was not slow enough for 
 complete lapidification ; or they have an undefined base, 
 when examined in thin slices, which the microscope does 
 _not resolve into crystalline grains. Such portions of a rock 
 are described as wnindividualized: An unindividualized 
 base exists in the basalt of Truckee Valley, the character of 
 a slice from which, highly magnified, is given in fig. 7, from 
 Zirkel; feldspar crystals, of their usual rectangular forms 
 (part of them sanidin), one of the largish crystals of chryso- 
 lite, and smaller irregularly-shaped augites, are imbedded in 
 a base which consists of a glass-like substance; and in this 
 material there are extremely small globulite grains which 
 are globules of devitrified glass or incipient crystals. ‘The 
 glassy unindividualized base occupies the spaces among the 
 crystalline portions. 7 
 
 These differences in crystalline texture are of small im- 
 portance compared with differences in mineral and chemi- 
 cal composition. They are results of accidents, and, at 
 the best, lead only to a distinction of varieties among kinds 
 of rocks. The presence of a little glass, or of disseminated 
 large crystals in a porphyritic way, does not make the rock 
 essentially different in kind. . If, however, the glassy na- 
 ture is manifest in the external appearance of the mass, it 
 is convenient to call the rock by a separate name. 
 
 Porphyritic rocks are sometimes named as if porphyry 
 was a distinct kind of rock, or as if the porphyritic section 
 of a kind of rock merited ’special prominence. But, as re- 
 cognized beyond, “‘felsyte-porphyry ” is porphyritic felsyte ; 
 “‘dioryte-porphyry” is porphyritic dioryte ; ‘* diabase-por- 
 
 27 
 
418 DESCRIPTIONS OF ROCKS. 
 
 phyry” is porphyritic diabase, or, since diabase cannot be 
 distinguished mineralogically from doleryte, it is porphy- 
 ritic doleryte ; and, in these and other like cases, the being 
 porphyritic is a characteristic of minor value. 
 
 Sometimes igneous rocks exhibit under the microscope a 
 fluidal texture; that is, the material, when examined in 
 sections, shows wavy lines or bands, which are evidence of 
 a former fluid state, and of movement or flowing when in 
 ‘that state. One variety of this texture is represented in fig- 
 ure 8 (from Zirkel), giving a magnified view of an eruptive 
 
 
 
 ‘‘Rhyolyte ;” Fluidal texture. 
 
 alized. 
 
 rock from the head of Louis Valley, Nevada ; and another 
 in figure 5, p. 416. Such rocks have been comprised under 
 the general name of Rhyolyte (from the Greek for flowing) ; 
 but this fluidal texture is presented by rocks of different 
 mineral constitution, and is hence not a proper basis for a 
 kind of rock. 
 
 2. ANHYDROUS AND Hyprous CRYSTALLINE Rocks.— 
 Some eruptive rocks, like doleryte or trap, occur both an- 
 hydrous and hydrous. The latter,-unlike the former, have 
 the constituent minerals clouded in aspect, however thinly 
 sliced, and often changed in part to a green chlorite—a hy- 
 drous mineral—and also sometimes to other hydrous species. 
 Such rocks, moreover, have less lustre, and very frequently 
 they are amygdaloidal—that is, contain little cavities that 
 are often almond-shaped (the Latin amygdalwm meaning 
 
DESCRIPTIONS OF ROCKS. 419 
 
 almond), which were made by steam, or vapor of some kind, 
 and are now occupied by minerals. This hydrous or chloritic 
 condition is due to alteration, and hence such rocks are 
 properly only varieties of the anhydrous instead of being 
 distinct kinds. 
 
 The change was probably occasioned by subterranean wa- 
 ters, such as exist as streams among the earth’s strata, that 
 were encountered by the liquid rock when on its way up a 
 fissure toward the surface. Hydrostatic pressure prevented 
 the waters from being driven back by the heat, and conse- 
 quently the vapors were forced to penetrate the igneous 
 mass. In the region of New Haven, Conn.—lying at the 
 south extremity of the Connecticut Valley—the Triassic 
 trap-dikes of the western border of the region, and those 
 outside of the Trias, east or west, in the metamorphic 
 rocks, are anhydrous, while those in the middle of the valley 
 and east of this are mostly hydrous, showing a difference in 
 exposure to the waters according to the geographical position 
 of the dikes in the valley. Of two parallel ranges of dikes, 
 not half a mile apart, and following concentric curves in 
 their courses (situated twenty miles and more north of New 
 Haven), one (as Percival recognized) is amygdaloidal and 
 hydrous, and the other nearly anhydrous; and the positions 
 of the two kinds, there and elsewhere in the Connecticut 
 Valley, indicate a general relation between the direction of 
 the present valleys and that of the subterranean water-chan- 
 nels of Mesozoic time. | 
 
 In very many places coal-like ‘‘ inspissated bitumen” 
 occurs in the amygdaloidal cavities, which was apparently 
 derived from mineral oil that the action of the heat on the 
 Triassic carbonaceous shales (in some places abounding in 
 fossil fishes) had caused to rise in vapors and penetrate the 
 melted rock. ‘The carbonic acid of the calcite that so often 
 constitutes the amygdules probably came from the action 
 of the heat on limestone encountered atthe same time. 
 The deoxidizing action of the carbohydrogen vapors is sup- 
 posed by J. Lawrence Smith to account for the metallic 
 iron found in some trap or doleryte. The minerals which 
 constitute the amygdules (see p. 297) are largely such as 
 may have been made by the aid of heat and moisture out of 
 the minerals of the rock itself at the points where they occur. 
 
 The water that caused the change could not have come from above 
 after the rock was cooled; for the slight surface decomposition the 
 
420 DESCRIPTIONS OF ROCKS. 
 
 anhydrous trap now undergoes shows that such waters do not make 
 their way down: and moreover the results could not have been pro- 
 duced without heat. The trap has not been subjected to a metamor- 
 phic process ; for the Triassic beds are unaltered sandstone. The water 
 was not from the deep-seated source of the erupted trap, for, if so, the 
 dikes would have been all of one kind, instead of being part hydrous 
 and part anhydrous, and the former locally distributed just as subter- 
 ranean streams of water are likely to be. 
 
 In the case of hydrous metamorphic rocks, whether con- 
 taining chlorite, tale, or a hydrous mica, the hydrous min- 
 erals were, with rare exceptions, made at the time of the 
 crystallization, and are not a consequence of subsequent al- 
 teration. 
 
 3. DURABILITY IN Rocks.—Durability in a rock is due 
 largely (1) to compactness and fineness of texture ; and 
 (2) to the absence of any ingredient or mineral that is liable 
 to oxidation. As far within arock as water and air can gain 
 access, degradation will always be going on, whatever the 
 rock. ‘The alternate melting and freezing of the cold sea- 
 son will be one means of destruction; and direct chemical 
 action of the moist air, and especially of the carbonic acid it 
 contains (p. 108), will be another. This carbonic acid may 
 take the alkalies out of the feldspar of a granite ; and with 
 the commencement of the action the rock will begin at sur- 
 face to fall to pieces, or at least to show weakness. 
 
 Hence the practice of testing the durability of a stone for 
 architectural purposes, by putting it into water, and then 
 weighing it, after some days of exposure, to see whether it 
 has gained in weight, is a good one. 
 
 Fineness of grain gives further protection against destruc- 
 tion. Alternate heating and cooling in the daily passage of 
 the sun is a destroying agency of great effect, especially on 
 coarse-grained kinds. Rocks have often retained the glacier 
 markings upon them perfectly fresh until now, when they 
 have had a covering of two or three feet of earth; and they 
 have lost such markings after a few years of exposure. This 
 happens often where there is no true decomposition or Ox- 
 idation of the surface portion of the rock, and must be due 
 largely to the expansion and contraction caused by changing 
 temperature. The finer the grain of the rock the less the 
 chance for this action. There is no more durable rock than 
 a roofing-slate of good quality. Granites, when well pol- 
 
 ished, will usually resist long all weathering agencies, 
 
DESCRIPTIONS OF ROCKS. 49] 
 
 The presence of an oxidizable ingredient is a common 
 source of destruction. Pyrite occurs in grains or crystals 
 in almost all kinds of rocks; and it generally oxidizes 
 easily whenever water and air get access to it. Only the 
 firmest crystals resist change, and these not always. A rock 
 containing even a little pyrite can seldom be trusted for 
 architectural purposes. If a limestone contain a few per 
 cent., or even one, of iron or manganese replacing part of 
 the calcium, it has a source of destruction within it. The 
 iron and manganese are sure, after a while, to oxidize ; the 
 iron will give rusty stains, and the manganese turn it black, 
 and both will work destruction. A chemical trial is needed 
 to ascertain the fact as to the purity or not of the rock. 
 The presence of iron carbonate (siderite or spathic iron) is 
 the occasion, wherever it exists, of rapid decomposition as 
 far down as moisture and air can reach. This has been one 
 source of the changes producing the great beds of limonite 
 (like those of Western Massachusetts, Salisbury, Connecti- 
 cut, and other places), in which the rocks are sometimes de- 
 composed to a depth exceeding one hundred feet. 
 
 It is a fact to be remembered that a rock which has stood 
 the weather for centuries in its native exposure is a safe 
 material for man’s structures ; and one that is crumbling is 
 worth little or nothing. 
 
 Durability depends much on the climate. In Peru, even 
 sun-burnt bricks will last for centuries. 
 
 The resistance to crushing in rocks is ascertained by sub- 
 jecting cubes of a given size to pressure. In recent experi- 
 ments by P. Michelot,* Minister of Public Works in France 
 (whose trials numbered over 10,000), the most compact 
 limestones, weighing 2,700 kilograms per cubic meter, were 
 crushed by a weight of 900 kilograms per square centimetre. 
 Compact odlitic limestone of Bourgogne and some other 
 French localities, weighing 2,600 to 2,700 kilograms, bore 
 100 to 900 kilograms before crushing. Statuary and decora- 
 tive marbles bore 500 to 700 kilograms. 
 
 Of granitic rocks from Brittany, the Cotentin, the Vosges, 
 and the Central Plateau of France, weighing 2,600 to 2,800 
 kilograms, the best, which admitted of polishing, bore 1,000 
 to 1,500 kilograms; while the coarser granites of Brest and 
 
 
 
 * Exposition Universelle de 1873 4 Vienne, p. 401-432; and Annales des Ponts et 
 Chaussées, 1863, 1868, 1870. 
 
429 DESCRIPTIONS OF ROCKS. 
 
 Cherbourg and the syenyte of the Vosges bore 700 to 1,000 
 kilograms; and other coarse granites, in which the large 
 crystals of feldspar were in part decomposed, bore only 400 
 to 600 kilograms. The green porphyry of Ternuay (Haute 
 Sadne), bore 1,360 kilograms ; the basalt of Estelle (Puy 
 de Dome), 1,880 kilograms. 
 
 In trials by Gen. Gilmore, trap of New Jersey required 
 to crush it 20,750 to 24,040 lbs. a square inch (about 6 c. 
 m. sq.); granite of Westerly, R. L, 17,790 ; id. of Rich- 
 mond, Va., 21,250; syenyte of Quincy, 17,750 ; marble of 
 Tuckahoe, N. Y., 12,950 ; id. of Dorset, Vt., 7,612 ; lime- 
 stone of Jolict, Ill., 11,250; sandstone of Belleville, N. J., 
 10,250; id. of Portland, Ct., 6,950; id. of Berea, O., 
 8,300; id. of Amherst, O., 6,650; id. of Medina, N. Y., 
 17,250 ; id. of Dorchester, N. B., 9,150. 
 
 When absorbent rocks are thoroughly wet the weight re- 
 quired to crush them is greatly reduced. ‘To crush wet chalk, 
 according to trials by Delesse, required only one-third what 
 it did when stove-dried; and for the limestone, ‘‘ calcaire 
 grossier,” of Vitry and other localities, mostly one-third to 
 one-half. 'Tournaire and Michelot found, for the chalk of 
 the Paris basin, the pressure required when wet two-ninths 
 of that required when the rock had been dried at a tempera- 
 ture considerably above 212° F. 
 
 Use of the Microscope in the Study of Rocks. The study of 
 thin, transparent slices of rocks by the microscope is of in- 
 terest whether the crystalline rock be coarse or fine in tex- 
 ture; but it is particularly important when of the latter 
 kind. There is no rock so opaque that it cannot be made 
 transparent, or at least translucent, in thin slices. Such 
 slices are examined by means of a polariscope-microscope. 
 ‘The increased use of the microscope in the investigation of 
 rocks has led to the introduction, by way of distinction in 
 methods of study, of the word macroscopic. An investiga- 
 tion may be carried on macroscopically, that is, without the 
 use of a microscope, excepting a pocket lens ; or microscopt- 
 cally, that is, by the study of thin slices through the aid of 
 the microscope and polariscope. 
 
 The more important points ascertained by microscopic 
 methods, as regards the mineral constitution of a rock, are 
 the following: 
 
 1. The presence or not of quartz; of a feldspar; of a 
 chlorite. 
 
DESCRIPTIONS OF ROCKS, 423 
 
 2. The distinction of a triclinic feldspar from orthoclase, 
 the former showing in’ sections, cut in any direction ex- 
 cepting one, commonly several parallel spectrum bands, due 
 to multiple twinning in the crystal, while orthoclase shows 
 no bands of the kind, or at the most but two. 
 
 _ 3. The presence or not of hornblende ; this mineral hav- 
 ing often cleavage lines meeting at angles of 124°, and being 
 dichroic. : 
 
 4. The presence or not of pyroxene ; this mineral often 
 showing cleavage lines meeting at angles of 87° (nearly a 
 right angle), and being not dichroic, and usually distin- 
 ewished in this way from hornblende. 
 
 5. The presence or not of mica, its cleavage lines and 
 dichroism affording distinctive characters. 
 
 6. The presence or not of chrysolite ; of magnetite, its 
 form being often octahedral, and single or grouped; of 
 
 11. 
 
 
 
 Magnetite in grouped Liquid Carbonic Cube of Salt in a solu- 
 crystals. Acid. tion of the same. 
 
 points or portions having the nature of glass, and therefore 
 not polarizing light; of fluidal lines; of liquid carbonic acid, 
 and of various other inclusions. Vig. 9 shows a common 
 form of the grouping of microscopic magnetite crystals 
 in an eruptive rock. Fig. 10 represents a cavity in quartz 
 nearly filled with a liquid, d—the small bubble, ¢, showing 
 the part not occupied by it- When the liquid is carbonic 
 acid the air-bubble disappears on raising the temperature to 
 86°-95° F. Carbonic acid requires a pressure, at 32° F., of 
 384 atmospheres to retain it in the liquid state ; and hence 
 occurs liquid only in quartz, topaz, and a few other miner- 
 als. Fig. 11 (from Zirkel) shows another cavity, containing, 
 besides a liquid, a little cube and microscopic hornblende- 
 like acicular crystals ; and the cube is supposed to be com- 
 mon salt in a solution of salt. Hexagonal prisms of apa- 
 tite (calcium phosphate) are detected by the microscope in 
 
_ 
 
 424 DESCRIPTIONS OF ROCKS. 
 
 almost all kinds of igneous and metamorphic rocks, includ- 
 ing trap or doleryte. 
 
 For a particular account of the distinguishing character- 
 istics of minerals studied by microscopic methods, reference 
 must be made to treatises on the subject. 
 
 IV. KINDS OF ROCKS. 
 
 1. Rocks are generally mixtures of two, three, or four 
 prominent mineral constituents, with also others, it may be, 
 of less importance. Each mineral adds a distinctive fea- 
 ture, and might be a reason for a new name. But it 1s 
 usual with lithologists to base the distinction into kinds of 
 rocks on the ¢wo chief minerals, and make the others acces- 
 sory species and the basis only of varieties. This method 
 is prompted by convenience, and also by the fact that the 
 more important characteristics are commonly contained in 
 two of the constituent minerals. It has many exceptions, 
 however, and particularly where a third mineral has special 
 peculiarities and abundance. 
 
 2 Difference in kind of rock is naturally based on dif- 
 ference in chemical or mineral constitution, and identity, 
 accordingly, on essential identity in this respect. Conse- 
 quently when there is no essential difference in chemical or 
 mineral constitution, there is no sufficient reason for a dis- 
 tinction in kind or a difference in name, unless the wide 
 distribution of a particular variety, and the permanence in 
 its characters, make the distinction in name a geological 
 necessity. 
 
 In accordance with this statement, the distinctions among 
 crystalline rocks of coarse or fine in texture; of being por- 
 phyritic or not; of containing glassy grains among the 
 stony or not; of being foliated or not in crystallization, are 
 of little value compared with the real mineral constitution, 
 and are a fit basis only, at the best, for varieties. But the two 
 rocks of like composition, trachyte and felsyte, retain their 
 characteristics so widely, that geology needs both names, 
 and only demands that their essential identity should be 
 held in mind. 
 
 The same kind of rock is in many cases both of metamor- 
 phic and eruptive origin ; still the difference of origin is 
 not a sufficient basis for a distinction of kind unless there 
 is some marked difference between them, and an extended 
 
 ~ta 
 
KINDS OF ROCKS. 425 
 
 distribution of each, that makes the case like that of tra- 
 chyte and felsyte. ‘The author has proposed to use the pre- 
 fix meta for metamorphic kinds when a rock occurs both 
 metamorphic and eruptive ; but this is not intended to indi- 
 cate a distinction in kind, but only to abbreviate the qualify- 
 ing word metamorphic. 
 
 According to the principles above stated, a rock having 
 oligoclase or albite as its feldspar constituent cannot rightly 
 have the same name with one having either of the dasic 
 feldspars, labradorite or anorthite, as an essential part, 
 although these feldspars are all embraced under the decep- 
 tive title of plagioclase (p. 275). Between anorthite and 
 oligoclase there is a difference of 20 per cent. in the silica, 
 and the former is simply a lime feldspar; and the contrast 
 is large also between labradorite and oligoclase. Again, for 
 a like reason, as already explained (p. 411), a mica-bearing 
 rock containing little or no hornblende cannot properly be 
 classed with hornblendic rocks. 
 
 3. It has been supposed that pre-Tertiary crystalline rocks 
 differed so decisively from the Tertiary and more recent, 
 that those of the two series should not bear the same name. 
 But geology knows nothing of any epoch of sudden transi- 
 tion in the mineral nature of eruptive rocks at the com- 
 mencement of the Tertiary era; on the contrary, it shows 
 that the kinds made before and after this epoch are alike 
 in mineral constitution, and differ not always even in tex- 
 ture, but only in the greater prevalence after the Tertiary of 
 volcanic or subaerial ejected masses, and therefore of rocks 
 of the texture this involves. The distinction of doleryte 
 from diabase, with others similar, is of this chronological 
 kind. Rocks, like other objects in science, should evidently 
 be named from what they are, and not from the age in 
 which they may have been made. 
 
 4, Since quartz is the most abundant of all the minerals 
 of the globe, it is the least characteristic of the ingredients of 
 compound rocks. Recent lithologists have made it, in sev- 
 eral cases, distinguish only a section under a kind of rock. 
 Thus, there are dioryte and quartz-dioryte, felsyte and 
 quartz-felsyte, trachyte and quartz-trachyte. On the same 
 principle there are syenyte and quartz-syenyte, as adopted 
 beyond. 
 
 5. The division of crystalline rocks into acidic and basic 
 rocks is explained on p. 274. The acidic afford on analysis 
 
426 DESCRIPTIONS OF ROCKS. 
 
 55 per cent. or more of silica, and the basic usually less 
 than 52. 
 
 6. The feldspars are divided, according to their bases, 
 into (1) potash-feldspars, including orthoclase and micro- 
 cline; and (2) those which may be designated soda-lime- 
 feldspars, namely the species albite, oligoclase, andesite, 
 labradorite, and anorthite, which yield either soda, or lime, 
 or both, on analysis. The term plagioclase has been used 
 for the latter ; but it is no longer applicable since microcline 
 is plagioclase. Under the heading potash-feldspars, as used 
 beyond, leucite also is included; and under that of soda- 
 lime-feldspars, nephelite and sodalite, and also the minerals 
 of the saussurite group. 
 
 The kinds of rocks are described under the heads of— 
 1. FRAGMENTAL ROCKS, EXCLUSIVE OF LIMESTONES. 
 2, LIMESTONES, OR CALCAREOUS ROCKS. 
 
 3. CRYSTALLINE ROCKS, EXCLUSIVE OF LIMESTONES. 
 
 No strongly defined limit exists between the fragmental 
 and crystalline rocks. But still they are for the most part 
 widely diverse in character and aspect. 
 
 In the names of rocks, the termination ite is here changed to yte, as 
 done in the author’s ‘‘ System of Mineralogy ” (1868), in order to dis- 
 tinguish them from the names of minerals. Granite is excepted. 
 
 I, Fragmental Rocks, exclusive of Limestones. 
 
 1, Conglomerate.—A rock made up of pebbles or of coarse 
 angular fragments of rocks of any kind. (a) Ifthe pebbles 
 are rounded, the conglomerate is a pudding-stone ; (d) if 
 angular, a breccia. 
 
 Conglomerates are named according to their constituents, siliceous 
 or quartzose, granitic, calcareous, porphyritic, pumiceous, etc. 
 
 9. Grit.—A hard, gritty rock, consisting of coarse sand, 
 or sand and small pebbles, called also madllstone grit, be- 
 cause used sometimes for millstones. 
 
 3. Sandstone —A rock made from sand: a consolidated 
 sand-bed. 
 
 VARIETIES.—a. Siliceous or Quartzose ; consisting chiefly of quartz. 
 b. Granitic; made of granitic material or comminuted granite. c. Mi- 
 caceous ; containing much mica. 4d. Argillaceous ; containing much 
 clay with thesand. e. Gritty ; hard and containing small quartz peb- 
 
KINDS OF ROCKS. 427 
 
 bles. f. Ferruginous ; containing iron oxide and having its red color. 
 g¢. Concretionary ; made up of concretions. h. Laminated ; made up 
 of thin layers or lamine, or breaking into thin slabs, a characteristic 
 most prominent in argillaceous sandstones. i. #riable ; crumbling in 
 the fingers. j. Mossiliferous ; containing fossils. 
 
 The paving stone extensively used in New York and the neighbor- 
 ing States is a dwminated sandstone, of the upper part of the Hamilton 
 group in geology, quarried just south of Kingston, and at many other 
 places on the west side of the Hudson River. The rock is remarkable 
 for its very even lamination. In Western New York and in Ohio, the 
 Devonian sandstones, above the Hamilton group, together with the 
 Waverly group, afford a similar flag-stone. ‘The ‘‘ brown-stone” used 
 much in New York and elsewhere for buildings, is a dark-red sand- 
 stone from the Triassic formation, and is quarried at’ Portland, Conn., 
 on the Connecticut River, opposite Middletown. A lighter-colored 
 ‘* brown-stone ” or ‘‘ free-stonc,” of the same age, also much used for 
 buildings, comes from Newark, Belleville, Little Falls, and other points 
 in Central New Jersey. The handsome sandstone of light olive-green 
 tint, much employed in architecture, is from the Lower Carboniferous 
 group in New Brunswick. The soft white sandstone, in much esteem 
 among architects because so easily cut and carved, comes from Ohio 
 quarries, in beds of the Carboniferous ; it is mostly from a bed about 
 sixty feet thick, called the ‘‘ Berea grit,” and is obtained at Berea and 
 Independence in Cuyahoga County, and Amherst in Lorain County, and 
 elsewhere. 
 
 Pyrite is often present in sandstones used for building, and has de- 
 faced, and is destroying, many a beautiful structure by its oxidation, 
 and the consequent decay of the rock. 
 
 Sandstones absorb moisture most easily in the direction of the bed- 
 ding or grain, if there is any distinct bedding; and hence the blocks, 
 when used fora building or wall, should be placed with the bedding 
 horizontal. It is, further, the position in which the stone will stand 
 the greatest pressure. 
 
 Grindstones are made from an cven-grained, rather friable sand- 
 stone, and are of different degrees of fineness, according to the work 
 to be done by them. 
 
 Hard siliceous sandstones and conglomerates, occurring in regions of 
 metamorphic rocks, are called ‘‘ granular quartz,” and quurtzyte (p.435). 
 
 4, Sand-rock.—A rock made of sand, especially when not 
 of siliceous material. A calcareous sand-rock is made of cal- 
 careous sand ; it may be pulverized corals or shells, such as 
 forms and constitutes the beaches on shores off which living 
 corals and shells are abundant. 
 
 The beach sands become cemented below high-water mark into a 
 
 calcareous sand-rock, which consists of layers having the pitch of the 
 surface of the beach. They are often coarse, calcareous conglomerates. 
 
 5. Shale.—A soft, fragile, argillaceous rock, having an 
 uneven slaty structure. Shales are of gray, brown, black, 
 dull-greenish, purplish, reddish and other shades. 
 
428 DESCRIPTIONS OF ROCKS. 
 
 VARIETIES.—a. Bituminous shale, or Carbonaceous shale (Brand- 
 schiefer of the Germans), impregnated with coaly material and yielding 
 mineral oil or related bituminous matters when heated. b. Alum shale; 
 impregnated with alum or pyrites, usually a crumbling rock. The 
 alum proceeds from the alteration of pyrite or the allied pyrrhotite 
 (p. 174). 
 
 6. Argillyte, or Phyllyte-—An argillaceous slaty rock, 
 like shale, but differing in breaking usually into thin and 
 even slates or slabs. Roofing and writing slates are exam- 
 ples. It is sometimes thick-laminated. Unlike shale, it 
 occurs in regions of metamorphic rocks, and often graduates 
 into hydromica, chloritic, and mica schists, and also, on 
 the other hand, into shale. Often called Clay-slate. 
 
 VARIETIES.—-a. Bluish-black. b. Tile-red. c. Purplish. d. Grayish. 
 e. Greenish ; £. Ferruginous. g. Pyritiferous. h. Thick-laminated ; 
 affording thick slabs, instead of slates. i. Thick-bedded ; a massive 
 rock, affording thick blocks or masses. j. Staurolitic. k. Ottrelitic. 
 
 Extensive quarries of slate exist in Vermont at Waterford, Thet- 
 ford, and Guilford, in the eastern slate range of the State ; in North- 
 field in the central range, and in Castleton and elsewhere in the 
 western range, the last of Lower Silurian age if not the others. There 
 are excellent quarries also in Maine and Pennsylvania. The rock fur- 
 nishes also thick slabs for various economical purposes. A trial as 
 to water absorption, and a close examination as to the presence of 
 pyrite, is required before deciding that a slate rock is fit for use, how- 
 ever even its fissile structure. Kinds with a glossy surface are most 
 likely to be impervious to moisture. 
 
 7. Tufa.—A sand-rock or conglomerate made from com- 
 minuted volcanic or other igneous rocks, more or less altered. 
 Usually of a yellowish-brown, gray, or brown color, some- 
 times red. 
 
 VARIETIES.—a. Dolerytic or basaltic; tufa made from those igneous 
 rocks that contain iron-bearing minerals, such as doleryte (trap), basalt, 
 and the heavier lavas; it is usually yellowish-brown or brown in 
 color, sometimes red ; and often consists in part of palagonite (p. 312). 
 b. Trachytic; made of the feldspathic igneous rock, trachyte, of an ash- 
 gray color, or of other light shades.. c. Pwmiceous ; made of frag- 
 ments of pumice. Pozewclana is a light-colored tufa, found in Italy. 
 near Rome, and elsewhere, and used for making hydraulic cement, 
 Wacke is an earthy brownish rock, resembling an earthy trap or dole- 
 ryte, usually made up of trappean or dolerytic material, compacted 
 into a rock that is rather soft. . 
 
 8. Sand. Gravel—Sand is comminuted rock-material ; 
 but common sand is usually comminuted quartz, or quartz 
 and feldspar, while gravel is the same mixed with pebbles 
 and stones. Sand often contains grains of magnetite, or 
 
KINDS OF ROCKS. 429 
 
 of garnet, or of other hard minerals existing in the rocks of 
 the region. Occasionally magnetite or garnet is the chief 
 constituent. 
 
 Volcanic sand, or Peperino, is sand of volcanic origin, 
 either the ‘‘ cinders” or ‘‘ ashes” (comminuted lava), 
 formed by the process of ejection, or lava rocks otherwise 
 comminuted. 
 
 9. Green Sand.—An olive-green sand-rock, friable, or not 
 compacted, consisting largely of glauconite. See, for do- 
 scription and analysis, p. 307. 
 
 10. Clay.—Soft, impalpable, more or less plastic material, 
 chiefly aluminous in composition, white, gray, yellow, red 
 to brown in color, and sometimes black. It has been made 
 chiefly from the feldspars, by decomposition. See Kaolinite. 
 
 VARIETIES. — a. Jfaolin, purest unctuous clay. b. Potter’s clay, 
 plastic, free from iron; mostly unctuous; usually containing some 
 free silica. Pipe-clay is similar. c. Fire-brick clay, the same ; but it 
 » may contain some sand without injury. d. Herruginous, ordinary 
 brick-clay, containing iron in the state of oxide or carbonate, and con- 
 sequently burning red, as in making red brick. e. Containing iron in 
 _ the state of silicate, and then failing to turn red on being burnt, as the 
 clay of which the Milwaukee brick are made. f. Alkaline and Vitri- 
 fiable, containing 2°5 to 5 per cent. of potash, or potash and soda, 
 owing to the presence of undecomposed feldspar, and then not refrac- 
 tory enough for pottery or fire-brick. g. Marly, containing some Car- 
 bonate of calcium. h. Weak clay, containing too much sand for brick- 
 making. i. Alum-bearing, containing aluminous sulphates, owing to 
 the decomposition of iron sulphides present, and hence used for mak- 
 ing alum. ; 
 
 The red pipestone of the North American Indians is an indurated 
 clayey rock from the Coteau de Prairies ; it has been named Catlinite; 
 and the gray is in part compact argillyte. 
 
 11, Alluvium. Silt. Till—AJ/uvium is the earthy deposit 
 made by running streams or lakes, especially during times 
 of flood. It constitutes the flats either side, and is usually in 
 thin layers, varying in fineness or coarseness, being the re- 
 sult of successive depositions. 
 
 Silt is the same material deposited in bays and harbors, 
 where it forms the muddy bottoms and shores. 
 
 Lass is a fine earthy deposit, following the courses of 
 valleys or streams, like alluvium, but without division into 
 thin layers. Occurs in elevated plains, along the broad parts 
 of large valleys, as the Mississippi, Rhine, Danube. 
 
 Tilt is the unstratified sand, gravel, and stones, derived 
 from glaciers. 
 
430 DESCRIPTIONS OF ROCKS. 
 
 Detritus (from the Latin for worn) is a general term ap- 
 plied to earth, sand, alluvium, silt, gravel, because the ma- 
 terial is derived, to a great extent, from the wear of rocks 
 through decomposing agencies, mutual attrition in running 
 water, and other methods. — , 
 
 Soil is earthy material mixed with the results of vegeta- 
 ble and animal decomposition, whence it gets its dark color 
 and also a chief part of its fertility. 
 
 12. Tripolyte (Infusorial Earth).— Resembles clay or chalk, 
 but isa little harsh between the fingers, and scratches glass 
 when rubbed on it. Consists chiefly of siliceous shells 
 of Diatoms with often the spicules of sponges. Forms 
 thick deposits, and is often found in old swamps beneath 
 the peat. 
 
 This soft diatomaceous material is sold in the shops under the namo 
 of silex, electro-silicon, and polishing powder, and is obtained for com- 
 merce in Maine, Massachusetts, Nevada, and California. A bed ex- 
 ceeding fifty feet in thickness occurs near Monterey in California ; and 
 other large beds in Nevada near Virginia City, and elsewhere. Itis 
 used as a polishing powder; in the manufacture of ‘‘soluble glass; ” 
 and also mixed with nitro-glycerine to make dynamite. Occurs some- 
 times slaty, as at Bilin, Prussia; and also hard or indurated, from con- 
 solidation through infiltrating waters, and thus graduates, at times, 
 into chert. Consists of silica in the opal or soluble state. 
 
 II. Limestones or Calcareous Rocks. 
 1. Not CRYSTALLINE. 
 
 1, Massive Limestone.—Compact uncrystalline limestone 
 usually of dull gray, bluish-gray, brownish, and black colors, 
 sometimes yellowish-white, cream-colored, nearly white, 
 and red of different shades ; in texture, varying from earthy 
 to compact semi-crystalline. It consists essentially of cal- 
 cite or calcvum carbonate (p. 215), but often contains clay or 
 sand, or other impurities. 
 
 VARIETIES.—The varieties depending on color are very numerous, 
 and many of them, when pure and compact, are polished and used 
 for marble. The gray and black colors are due commonly to carbo- 
 naceous material, for they burn white ; but the yellow, red, and some 
 other kinds to the presence of iron-oxide. There are also: a. Fossil- 
 iferous or shell limestone. b. Coral or Madreporic limestone. c. En- 
 clinital or Crinoidal limestone ; containing crinoidal remains in the 
 form mostly of small disks. d. Wwmmutlitic ; containing the disk- 
 shaped fossils called Nummulites. e. Odlitic limestone ; a limestone 
 having an odlitic texture. f. Bird’s - eye limestone; having small 
 whitish crystalline points scattered through it, a rock of Western 
 
KINDS OF ROCKS. ASI 
 
 New York, of the Trenton period in geology. g. Conglomerate lime- 
 stones, 
 
 The black marble of the United States comes mostly from Shore- 
 ham, Vermont, and other places in that State, near Lake Champlain, 
 and from near Plattsburg and Glenn’s Falls, N. Y.; also from Isle 
 La Motte. A pudding-stone marble, of various dull shades of color, 
 occurs on the banks of the Potomac, in Maryland, 50 or 60 miles above 
 Washington ; it is used for columns in the interior of the Capitol at 
 Washington. 
 
 The Portor is a Genoese marble very highly esteemed ; it is deep 
 black, with veinings of yellow ; the most beautiful comes from Porto- 
 Venese. The Nero-antico marble of the Italians is an ancient deep 
 black marble ; the paragone is a modern one, of a fine black color, 
 from Bergamo ; and panno di morte is another black marble with a 
 few white fossil shells. , 
 
 A beautiful marble from Sienna, drocatello di Siena, has a yellow 
 color, with large irregular spots and veins of bluish-red or purplish. 
 The mandelato of the Italians is a light red marble, with yellowish- 
 white spots. The Madreporic marble is the Pietra stellaria of the 
 Italians. 
 
 Fire-marble, or lumachelle, is a dark brown shell marble, having 
 brilliant fire-like or chatoyant reflections from within. 
 
 Ruin marble is a yellowish marble, with brownish shadings or lines 
 arranged so as to represent castles, towers, or cities in ruins. These 
 markings proceed from infiltrated iron. It is an indurated calcareous 
 marl, and does not occur in large slabs. 
 
 Hydraulic limestone is a compact kind containing some clay, and 
 affording a quicklime the cement from which will set under water. 
 An analysis of a kind from Rondout, N. Y., afforded Carbonic acid 
 34:20, lime 25°50, magnesia 12°35, silica 15°37, alumina 9°13, iron 
 sesquioxide 2°25. In making ordinary mortar, quartz sand is mixed 
 with pure quicklime and water, and the chemical combination is 
 mainly that between the water and lime, together with subsequently 
 an absorption of carbonic acid. With “ hydraulic cement,” silica and 
 alumina (that of the clay) are disseminated through the lime, and 
 hence these ingredients enter into chemical union with the lime and 
 water, and make a much firmer cement, and one which “sets” under 
 water. 
 
 Oil-bearing limestones occasionally occur. A kind used for build- 
 ing in Chicago, of the Niagara period, becomes spotted or streaked 
 with blackish mineral oil, after a few years’ exposure to the weather. 
 
 Some of the pyramids of Egypt, including the largest, the pyrs- 
 mid of Cheops, is made of nummulitic limestone ; and this is tl.c 
 building material of Aleppo, the range of mountains between Aleppo 
 and Antioch being composed largely of this cream-colored rock. 
 
 A soft Tertiary limestone occurring in the vicinity of Paris has 
 afforded a vast amount of rock, of an agreeable pale yellowish color, 
 for fine buildings in Paris; and a similar rock has long been used in 
 Marseilles, Montpellier, Bordeaux, Brussels, and, other places in West- 
 ern Europe. 
 
 Most limestones have been made out of comminuted shells, corals, 
 and other like material ; and when of dark colors or black, it is usu- 
 ally owing to some carbonaceous matters present derived from the de- 
 
432 DESCRIPTIONS OF ROCKS. 
 
 Peres of the plants or animals of the waters in which they were 
 ormed. 
 
 When burnt, limestone (Ca0,C) becomes quicklime (CaO), through 
 loss of carbonic acid (CO,) ; and, at the same time, all carbonaceous 
 materials are burnt out, and the color, when it is owing solely to these, 
 becomes white. 
 
 2. Magnesian Limestone. Dolomyte.—Carbonate of calcium 
 and magnesium, but not distinguishable in color or texture 
 from ordinary limestone. ‘The amount of magnesium car- 
 bonate afforded by analyses varies from a few per cent. to 
 that of true dolomite (p. 55). 
 
 Much of the common limestone of the United States is magnesian. 
 That of St. Croix, Wisconsin, the ‘‘ Lower Magnesian,” afforded Owen 
 42-43 per cent. of magnesium carbonate. 
 
 In some limestones the fossils are magnesian, while the rock is 
 common limestone. Thus, an O7thoceras, in the Trenton limestone of 
 Bytown, Canada (which is not magnesian), afforded T. 8. Hunt, Cal- 
 cium carbonate 56:00, magnesium carbonate 37°80, iron carbonate 5 95 
 —99°75. The pale-yellow veins in the Italian black marble, called 
 ‘‘Eeyptian marble,” and ‘ portor” (see above), are dolomite, accord- 
 ing to Hunt ; and a limestone at Dudswell, Canada, is similar. 
 
 8. Chalk —A white, earthy limestone, easily leaving a 
 trace on a board. Composition the same as that of ordi- 
 nary limestone. 
 
 4. Marl._—A clayey or earthy deposit containing a large 
 proportion of calcium carbonate—sometimes 40 to 50 per 
 cent. If the marl consists largely of shells or fragments 
 of shells, it is called Shell-marl. 
 
 Marl is used as a fertilizer ; and other beds of clay or sand that can 
 be so used are often in a popular way called mari. The “‘ Green 
 sand” of New Jersey (p. 429) is of this kind. 
 
 5. Travertine.—A massive limestone, formed by deposi- 
 tion from calcareous springs or streams. The rock abounds 
 on the river Anio, near Tivoli, and St. Peter’s at Rome is 
 constructed of it. ‘I'he name is a corruption of Tidurtine. 
 It occurs in the Yellowstone Park, along Gardiner’s River. 
 
 6. Stalagmite.—See page 216. 
 
 9. CRYSTALLINE LIMESTONE. 
 
 1. Granular or Crystalline Limestone (Marble).—Limestone 
 having acrystalline-granular texture, white to gray color, but 
 often of reddish and other tints from impurities. It is a 
 metamorphic rock ; it was originally common limestone ; it 
 became crystalline under the action of more or less heat ; in 
 
KINDS OF ROCKS. 433 
 
 the process all the fossils present were obliterated, except 
 in some cases of partial metamorphism. Its impurities are 
 often mica or tale, tremolite, white or gray pyroxene or scap- 
 olite ; sometimes serpentine, through combination with 
 which it passes into ophiolyte (p. 453) ; occasionally chon- 
 drodite, apatite, corundum. 
 
 VARIETIES.—a. Statuary marble; pure white and fine grained. 
 b. Decorative and Architectural marble ; coarse or fine, white, and 
 mottled of various colors, and, when good, free not only from iron in 
 the form of pyrite, but also from iron or manganese in the state of 
 carbonate with the calcium, and alsofrom all accessory minerals, even 
 those not liable to alteration, and especially those of greater hardness 
 than the marble which would interfere with the polishing. ¢. Verd- 
 antique, or Ophiolyte. d. Micaceous. e. Tremolitic; contains bladed 
 crystallizations of the white variety of hornblende called tremolite. 
 f. Graphitic; contains graphite in iron-gray scales disseminated 
 through it. g. Chloritic; contains disseminated scales of chlorite. 
 h. Chondroditic; contains disseminated chondroditc in large or small 
 yellow to brown grains. 
 
 White and grayish-white marble is abundant in Western New Eng- 
 land, and Southeastern New York (Westchester County). The tex- 
 ture is less coarsely crystalline in Vermont than in Massachusetts, the 
 crystallization of the limestone as well as of the associated schists in- 
 creasing in coarseness from the north to the south, or rather south- 
 southwest, which is the trend of the limestone belt. Fine marbles 
 are quarried in Dorset, West Rutland, Pittsford, and other places in 
 Vermont, and the best of statuary marble occurs abundantly in Pitts- 
 ford. The whitest marble of Rutland is not as firm as that mottled 
 with gray, owing apparently to the fact that it was made white by the 
 heat that crystallized it burning out any carbonaceous material ; while 
 at Pittsford, 16 miles to the north of Rutland, itis very firm, and is white, 
 probably, because it was made with less heat from a whiter lime- 
 stone. In Vermont, the best quarries occur where the strata stand 
 at ahigh angle: the layers in such regions were subjected to great 
 pressure in the upturning that gave them this position, and this pres- 
 sure has soldered many layers together in one that are separate where 
 the pressure was less; consequently blocks as large as an ordinary 
 house might be obtained at some of the quarries. Good marble is also 
 quarried in Pennsylvania, Maryland, and Tennessee. One of the most 
 beautiful marbles from deposits of crystalline limestone in the United 
 States, is the mottled reddish-brown from East Tennessee, and mainly 
 from Knox and Hawkins counties. Another handsome marble is the 
 mottled red of Burlington, Vt., from the semi-crystalline Winooski 
 limestone ; and a still finer the deeper red (or cherry-red), mottled and 
 veined with white, of Swanton, Vt., from the same limestone on the 
 northern borders of the State. 
 
 The Carrara marble of Italy, the Parian, of the island of Paros (the 
 birthplace of Phidias and Praxiteles), and the Pentelican, from quar- 
 ries near Athens, Greece, are examples of crystalline limestone. The 
 Carrara marble varies in quality from coarse to true statuary marble, 
 and the best comes from Monte Crestola, and Monte Sagro, Out cf 
 
 28 
 
434 DESCRIPTIONS OF ROCKS. 
 
 the 500 quarries only 20 furnish stone for the sculptor. The amount 
 of marble taken out from the quarries in 1876, was 120,000 tons, 
 valued at $2,400,000; and of this 40,000 tons came to the United 
 States. The Cipolin marbles of Italy are white, or nearly so, with 
 shadings or zones of green talc. 
 
 2, Dolomyte—Not distinguishable by the eye from gran- 
 ular limestone. 
 Part of the marbles above referred to are dolomyte. This is the 
 
 case with that of Westchester County, N Y., that of Canaan, Con- 
 necticut, and of Lee and Stockbridge, Massachusetts. 
 
 II. Crystalline Rocks, exclusive of Limestones. 
 
 The crystalline rocks may be distributed according to 
 their composition into the following series or groups. Hach, 
 excepting the first, embraces both metamorphic and eruptive 
 rocks. 
 
 1. Siliceous rocks, The kinds consisting mainly of quartz 
 or opal are here included. ‘The first of those mentioned, 
 page 435, is intermediate between the fragmental and meta- 
 morphic-crystalline rocks. The opal material is a chemical 
 deposit. ‘The chert of sedimentary formations is believed 
 to be mainly tripolite consolidated through the solution of a 
 part of its material by the permeating waters and its sub- 
 sequent desposition—tripolite or diatom beds being made 
 chiefly of opal-silica which. is readily soluble in waters 
 slightly alkaline. 
 
 9. The Mica and Potash-Feldspar series, ‘These are emi- 
 nently alkali-yielding rocks, both the mica, whether mus- 
 covite, biotite, or lepidomelane, and the feldspar, whether 
 orthoclase or microcline, affording on analysis, as explained 
 on page 411, much potash, and the feldspars often also some 
 soda. The soda feldspar, albite or oligoclase, is a common 
 accessory ingredient. The series shades off into a rock 
 that is chiefly feldspar, and another that is chiefly mica ; 
 and in these two extremes the amount of potash yielded is 
 about the same. Moreover, as leucite is essentially a potash- 
 feldspar in ratio and composition (see page 411), rocks, con- 
 sisting chiefly of leucite, without pyroxene or hornblende, 
 belong with this serics. Muscovite and_ biotite commonly 
 occur together, the formation of biotite having been deter- 
 mined by the presence of some iron oxide in the original 
 material from which it was made. The mica is sometimes 
 a hydrous species (page 313). 2 
 
KINDS OF ROCKS. 435 
 
 3. The Mica and Soda-lime-Feldspar series. These grani- 
 toid rocks are equally alkali-yielding with those of the true 
 granite group, but the alkali is mainly soda. ‘The nephelite 
 (elxolite) rocks not hornblendic are here included, although 
 they contain in general some microline or orthoclase. 
 
 4. The Hornblende and Potash-Feldspar series, or the Sye- 
 nyte group. In this series, the mica of the granite series is 
 replaced by the non-alkaline mineral, hornblende. Transi- 
 tions between the granite and syenyte rocks are common—a 
 bed that is true mica schist often becoming hornblendic ; 
 the same specimen may have mica and hornblende crystals 
 together, or parallel mica and hornblende layers, and then 
 not far beyond the schist may be a purely hornblende rock ; 
 and so there are similar transitions in other parts of the 
 two series. ‘This transition in a stratum of mica schist, a 
 metamorphic rock, indicates merely that the mud-bed or 
 sedimentary stratum, out of which the mica schist was 
 made, had a diminished proportion of alkali in some parts, 
 and, in still others, a complete absence of alkali—which is 
 just such a variation as might be looked for in oceanic sedi- 
 ments, as they spread over a wide region. ‘The hornblende 
 may be replaced by epidote, another iron-bearing mineral. 
 
 5. The Hornblende and Soda-lime-Feldspar series. The 
 soda-lime-feldspars, in this series, may be either of the 
 triclinic species, from albite to anorthite. 
 
 6. The Pyroxene and Soda-lime-Feldspar series. ‘'he soda- 
 lime-feldspars are the same as in the preceding. Quartz 
 is very rarely present, except in traces. Potash replaces 
 soda in amphigenyte. 
 
 7. Pyroxene, Garnet, Epidote and Chrysolite rocks, con- 
 taining little or no Feldspar. 
 
 8. Hydrous Magnesian and Aluminous rocks, 
 
 9. Iron Ore rocks. 
 
 
 
 1. SILICEOUS ROCKS. 
 
 1. Quartzyte, Granular Quartz.—A siliceous sandstone, 
 usually very firm, occurring in regions of metamorphic 
 rocks. It does not differ essentially from the harder sili- 
 ceous sandstones of other regions. Conglomerate beds are 
 sometimes included. 
 
 VARIETIES.—a. Massive. b. Schistose. c. Calcarcous ; sometimes 
 
 contains disseminated calcite which, where the rock is exposed tc 
 weathering, is removed and leaves the rock loose in texture, or cellu- 
 
436 DESCRIPTIONS OF ROCKS. 
 
 lar. d. Micaccous. e. Hydromicaceous ; it graduating at times into 
 hydromica or mica slate, f. Heldspathic, sometimes porphyritic (the 
 rock Arkose) ; this variety occurs north of Lenox, Mass., and when it 
 loses its feldspar, it becomes cellular, like buhrstone ; it has been used 
 for millstones. g. Gneissoid ; containing some mica and feldspar in 
 layers, and so graduating toward gneiss. h. Andalusitic ; containing 
 andalusite, as in Mt. Kearsarge (Hitchcock). i. Zowrmalinic ; containing 
 tourmaline. The vicinity of the great crystalline limestone formation 
 of the Green Mountain region, in Western New England (in Vermont 
 to the west of the principal ridge of the Green Mountains), includes 
 strata of quartzyte of great thickness, and high summits in Benning- 
 ton, and to the north, and also south, consist of it. In several places 
 the quartzyte strata graduate into, and also alternate with, hydromica 
 or mica slates, and in Massachusetts and Connecticut, with gneiss. 
 Between Bernardston, Mass., and Vernon, Vt., quartzyte occurs in 
 large beds, and also graduates into gneiss and hornblendic rocks. 
 Quartzyte exists also in the central part of Southern New Hampshire, 
 in the Archean area of Wisconsin, and in the Rocky Mountain region. 
 j. Novaculitic-quartzyte, or Novaculyte (Whetstone). Novaculyte is only 
 in part an extremely fine-grained siliceous rock. Of this nature is 
 the variety from Whetstone or Hot Spring Ridge, in Arkansas. This 
 ridge, 250 feet in height above the Hot Spring Valley, is made up of 
 the beautiful rock, ‘‘ equal,” says D. D. Owen, ‘‘in whiteness, close- 
 ness of texture, and subdued waxy lustre, to the most compact forms 
 and whitest varieties of Carrara marble. Yet it belongs to the age ot 
 the millstone grit.” Dr. Owen supposed it to have received its impal- 
 pable fineness through the action of the hot waters on sandstone. An 
 analysis of the rock afforded him (Second Rep. Geol. Arkansas, 1860, 
 p. 24), Silica 98-0, alumina 0°8, potash 0°6, soda 0°5, moisture, with 
 traces of lime, magnesia and fluorine 0':1=100. He states that along 
 the southern flank of the ridge there are over forty hot springs, having 
 a temperature of 100° F. to 148° F. Solid masses from the fine rock 
 have been got out weighing about 1,200 lbs.; the coarse varieties are 
 made into stones for bench tools. 
 
 2. Itacolumyte.—Schistose, consisting of quartz grains 
 with some hydrous mica; on account of the mica in the 
 lamination, it is sometimes flexible, and is called jlexidle 
 sandstone. 
 
 Occurs in the gold regions of North Carolina and Brazil, and dia- 
 
 monds are supposed to be sometimes connected as to origin with this 
 rock. 
 
 3. Siliceous Slate.—Schistose, flinty, not distinctly granu- 
 lar in texture. _ Sometimes passes into mica slate or schist. 
 
 4. Chert.—An impure flint or hornstone occurring in 
 beds or nodules in some stratified rocks. It often resem- 
 bles felsyte, but is infusible. Colors various. Sometimes 
 oblitic. “Kinds containing iron oxide graduate into jasper 
 and clay ironstone; and others, occurring as layers or no- 
 
KINDS OF ROCKS. 43” 
 
 dules in limestone are whitish, owing to the limestone 
 material they contain. Chert sometimes contains cavities 
 which are lined with chalcedony or agate, or with quartz 
 crystals. 
 
 5. Jasper rock.—A flinty siliceous rock, of dull red, yel- 
 low, or green color, or some other dark shade, breaking with 
 asmooth surface like flint. It consists of quartz, with more 
 or less clay and iron oxide. The red contains the oxide in an 
 anhydrous state, the yellow in a hydrous; on heating the 
 latter it turns red. 
 
 6. Buhrstone.—A cellular siliceous rock, flinty in texture. 
 Found mostly in connection with Tertiary rocks, and 
 formed apparently from the action of siliceous solutions on 
 preéxisting fossiliferous beds, the solutions removing the 
 fossils and leaving cavities. 
 
 Buhrstone is the material preferred for millstones. The buhrstone 
 of the vicinity of Paris, France, has long been largely exported for 
 
 this purpose. Good buhrstone is obtained also from the Tertiary in 
 Greenville District, South Carolina, 100 miles up the Savannah River. 
 
 7. Fioryte. (Siliceous Sinter, Pearl Sinter, Geyserite.)— 
 Opal-silica, in compact, porous, or concretionary forms, 
 often pearly in lustre ; made by deposition from hot sili- 
 ceous waters, as about geysers (Geyserite), or through 
 the decomposition of siliceous minerals, especially about 
 the fumaroles of volcanic regions. 
 
 Geyserite is abundant in Yellowstone Park, and about the Iceland 
 
 geysers ; after long exposure it crumbles down and becomes changed 
 to ordinary silica, or quartz. 
 
 2. MICA AND POTASH-FELDSPAR SERIES. 
 
 1. Granite.—Consists of quartz, orthoclase, and mica, and 
 has no appearance of layers in the arrangement of the mica 
 or other ingredients. G.=2°5-2°8. The quariz is usually 
 grayish-white or smoky, glassy, and without any appearance 
 of cleavage. The feldspar is commonly whitish or flesh- 
 colored, and may be distinguished from the quartz by its 
 cleavage surfaces, which reflect light brilliantly when the 
 specimen is held in the sunlight. The mica is usually in 
 small bright scales, either silvery, brownish-black, or black 
 in color, and the point of a knife carefully used will easily 
 split them into thinner scales; the silvery mica is muscovite, 
 but sometimes of the allied hydrous kinds, margarodite or 
 
438 DESCRIPTIONS OF ROCKS. 
 
 damoutite, and the black mica is usually biotite, though 
 occasionally the allied, more iron-bearing, species, lepidome- 
 lane. Oligoclase or albite is very often present. 
 
 Occurs both metamorphic and eruptive. Metamorphic 
 granite may often be seen graduating into gneiss, or lying 
 in beds alternating with gneiss. 
 
 ‘ -VaRrerres.—There are, A. Muscovite granites ; B. Biotite granites ; 
 
 C. Muscovite-and-biotite granites, the last much the most common. 
 The most of the following varieties occur under each except the horn- 
 blendic, which is usually a Biotite, or Muscovite-and-Biotite, granite. 
 There is also, D. Hydromica-granite. a. Common or Ordinary granite ; 
 the color is grayish or flesh-colored, according as the feldspar is white 
 or reddish, and dark gray when much black mica is present. Granite 
 varies in texture from fine and even, to coarse , and sometimes the 
 mica, feldspar, and quartz—especially the two former—are in large 
 crystalline masses. An average granite (mean of 11 analyses of Lein- 
 ster granite, by Haughton) affords Silica 72°07, alumina 14°81, iron 
 protoxide and sesquioxide 2°52, lime 1°63, magnesia 0°33, potash 5-11, 
 soda 2°79, water 1:09=100-35. b. Porphyritic granite ; has the ortho- 
 clase in defined crystals, and may be («) small porphyritic, or (/) large 
 porphyritic, and have the base (v) coarse granular, or (6) fine, and 
 even subaphanitic. c. Albitic granite; contains some albite, which is 
 usually white. d. Oligoclase granite (Miarolte) ; contains much oligo- 
 clase. e. Microcline granite ; contains the potash triclinic feldspar, 
 microcline. f. Hornblendic granite ; contains black or greenish-black 
 hornblende, along with the other constituents of granite. g. Black 
 micaceous granite ; consists largely of mica, with defined crystals 
 of feldspar (porphyritic), and but little quartz. h. Jolitic ; con- 
 taining iolite. i. Globuliferous granite ; contains concretions which 
 consist of mica, or of feldspar and mica. j. Gneissoid granite; % 
 granite in which there are traces of stratification; graduates into 
 gneiss. k. Pegmatyte, or Graphic granite ; consists mainly of ortho- 
 clase and quartz, with but little mica ; but the quartz is distributed 
 through the feldspar in forms looking like oriental characters. 
 
 A porphyritic granite, occurring at the junction of the andalusite 
 mica-argillyte (page 441) of the White Mountain Notch, N. H., with 
 the Mt, Willard granite, on the west side of Mt. Willard, conformable 
 with the bedding of the argillyte, has the argillyte for its base ; and 
 in it the orthoclase is in large well-defined crystals, and the quartz 
 in double six-sided pyramids, both easily separable from the matrix ; 
 the layer is six to twenty feet thick. 
 | The distinctions as to kinds of rocks between metamorphic and 
 eruptive granites are not yet made out. A porphyritic variety, having 
 the base fine-grained, occurs east of Parkview Peak, in the Rocky Mts., 
 which, according to Hague, is eruptive and related to the trachytes of 
 the region. The granite of New England is for the most part meta- 
 morphic or in veins. The following are prominent regions of the 
 granite quarries. In Maine: at Hallowell; a whitish granite, some- 
 times a little gneissoid ; at Rockport, whitish ; at Clarke’s Island, 
 spotted gray ; at Jonesbury, flesh-red ; also in the Mt. Desert region. 
 
KINDS OF ROCKS. 439 
 
 In New Hampshire, at various places, but most prominently near Con- 
 cord, a fine-grained whitish granite. In Massachusetts at several 
 points, especially in Gloucester at Rockport, a red granite. (The Quincy 
 ‘‘ oranite” is a syenyte.) In Rhode Island, at Westerly, a fine-grained 
 whitish granite. In Connecticut, at Millstone Point near Niantic, and 
 at Groton, near New London, a fine-grained whitish granite ; at Stoney 
 Creek, a pale reddish, but liable to large micaceous spots ; at Ply- 
 mouth, on the Naugatuck, a whitish granite, even and fine-grained 
 more easily worked than the Westerly. , 
 
 9. Granulyte. (Leptinyte.)—Like granite, but containing 
 no mica, or only traces. Metamorphic and eruptive. 
 
 VARIETIES.—-a. Common granulyte ; white and usually fine granu- 
 lar, a common rock in Western Connecticut and Westchester Co., New 
 York. b. Fesh-colored ; usually coarsely crystalline, granular, and 
 flesh-colored ; the coarse flesh-colored ‘‘ granite” of the Eastern or 
 Front Range of the Rocky Mts., in Colorado, sometimes called Aplite, 
 is partly of this kind ; it contains a little albite or oligoclase with the 
 orthoclase. c. Garnetiferous. da. Hornblendic; containing a little 
 hornblende—a variety that graduates into syenyte. e. MMagnetitic ; 
 containing disseminated grains of magnetite, a kind common in 
 Archean regions, in the vicinity of the iron ore beds, occurring in 
 Orange Co., N. Y., and south in New Jersey, and also at Brewster’s, 
 Dutchess Co., N. Y., and in Kent and Cornwall, Conn. f. Graphic 
 (Pegmatyte); like graphic granite, but containing no mica. The 
 coarser granulyte, especially that of veins, is often called pegmatyte 
 when not graphic. 
 
 3. Gneiss.—Like granite, but with the mica and other 
 ingredients more or less distinctly in layers. Gneiss breaks 
 most readily in the direction of the mica layers, and hence 
 its schistose structure; in consequence of this structure, 
 many kinds may be got out in slabs. It often graduates 
 imperceptibly into granite. Metamorphic. 
 
 VARIETIES. —Similar to those under granite. a. Porphyritie. pb. Al- 
 bitic. c. Oligoclase-bearing. 4a. Hornblendic. e. Micaceous. f. Globu- 
 liferous. g. Epidotic. h. Garnetiferous. i. Andalusitic ; contains an- 
 dalusite in disseminated crystals. j. Cyanitic ; contains cyanite, a 
 variety that has been observed on New York Island, and also in New- 
 town, Ct., Bellows Falls and elsewhere in N. H. k. Graphitic ; con- 
 tains graphite disseminated through it. 1. Quartzose ; the quartz 
 largely inexcess. m. Quartzytic ; consists largely of quartz in grains, 
 being intermediate between quartzyte and gneiss, a variety occurring 
 just northeast of Bernardston, Mass. Fig. 3 on page 415 represents, 
 natural size, a small piece of the porphyritic gneiss of Birmingham, 
 Conn. 
 
 Some gneiss is very little schistose, being in thick, heavy beds, 
 granite-like, while other kinds, especially those containing much 
 mica, are thin-bedded, and very schistose ; the latter graduate into 
 mica schist. The so-called granite of Monson, Mass., is a granitoid 
 gneiss. Its gneissoid structure facilitates greatly the quarrying. 
 
440 DESCRIPTIONS OF ROCKS. 
 
 4. Protogine. Protogine-gneiss.—Coarse to fine granular, 
 eranite-like or gneissoid in structure, and mostly the lat- 
 ter; of a grayish-white to greenish-gray color; consists of 
 quartz, white or grayish-white, rarely flesh-red, orthoclase, 
 a dark green mica and often chlorite, with some greenish- 
 white tale, and white oligoclase. Metamorphic. 
 
 The dark green mica approaches chlorite, as shown by Delesse, in 
 its very large percentage of iron oxide (Fe, 0, 21°31, FeO 5:03), but it 
 gave him only 0:90 of water, with 6:00 of potash. Among accessory 
 minerals are hornblende, titanite, garnet, serpentine, magnetite. In 
 an analysis of the protogine as a whole, Delesse obtained Silica 74:25, 
 alumina 11:58, iron oxide 2°41, lime 1:08, water 0:97, leaving 10°01 for 
 potash, soda and magnesia. From the region of Mont Blanc and 
 other parts of the Swiss Alps. 
 
 5. Mica Schist.—Consists largely of mica, with usually 
 much quartz, some feldspar, and, on account of the mica, 
 divides easily into slabs, that is, is very schistose. Usually 
 both of the potash micas, muscovite and biotite, are present, 
 and the latter (black mica) is commonly much the most 
 abundant. The colors vary from silvery to black, according 
 to the mica present. Often crumbles easily; and roadsides 
 are sometimes spangled with the mica scales. ‘The dissemi- 
 nated scales or crystals of biotite are sometimes set trans- 
 versely to the bedding. Metamorphic. 
 
 VARIETIES.—a. Gneissoid ; between mica schist and gneiss, and 
 containing much feldspar, the two rocks shading into one another. 
 b. Hornblendic. c. Garnetiferous. d. Staurolitic. e. Cyanitic. f. An- 
 dalusitic. g. Fibrolitice ; containing fibrolite. h. Tourmalinic. i. Cal- 
 careous ; limestone occurring in it in occasional beds or masses. 
 j. Graphitic, or Plumbaginous ; the graphite being either in scales or 
 impregnating generally the schist. k. Quartzose; consisting largely of 
 quartz. 1. Quartzytic ; a quartzyte with more or less mica, rendering 
 it schistose. m. Specular, or Itabyrite ; containing much hematite or 
 specular iron in bright metallic lamelle or scales. In fine-grained 
 mica schist, the scales of mica are sometimes scarcely visible without 
 a lens. 
 
 6. Hydromica Schist—A thin-schistose rock, consisting 
 either chiefly of hydrous mica, or of this mica with more 
 or less quartz; having the surface nearly smooth, and 
 feeling greasy to the fingers; pearly to faintly glistening in 
 lustre; whitish, grayish, pale greenish in color, and also of 
 darker shades. For analyses of hydrous micas see page 319. 
 Metamorphic, 
 
KINDS OF ROCKS. 441 
 
 © / 
 
 This rock used to be called talcose slate, but, as first shown by Dr. C. 
 Dewey, it contains no talc. It includes Parophite schist, Damourite 
 slate and Sericite slate (Glanz-Schiefer and Sericit-Schiefer of the Ger- 
 mans. ) 
 
 VARIETIES.—a. Ordinary ; more or less silvery in lustre. b. Chilo- 
 ritic ; contains chlorite, or is mixed with chlorite slate, and has there- 
 fore spots of olive-green color; graduates into chlorite slate. c. Gar- 
 netiferous. a. Pyritiferous ; contains pyrite in disseminated grains or 
 crystals. e. Magnetitic ; contains disseminated magnetite. f. Quart- 
 zytic; consists largely of quartzyte, or is a quartzyte rendered schistose 
 and partly pearly by the presence of hydrous mica, as is well seen ina 
 ridge northeast of Rutland, Vermont, which consists partly of quarizyte 
 and partly of hydromica schist. 
 
 7. Paragonite Schist—Consists largely of the hydrous 
 soda mica called paragonite (p. 314); but in other characters 
 resembles hydromica schist. Metamorphic. 
 
 8. Minette.—Brown to black, fine-grained, compact, not 
 distinctly schistose ; consisting of biotite (according to 
 the description and analysis of Delesse) and orthoclase ; 
 contains also a little hornblende. Occurs in beds in the 
 Vosges, France, associated with granite, syenyte, and other 
 crystalline rocks. Sometimes feebly porphyritic and small- 
 concretionary, the concretions consisting mainly of ortho- 
 clase. Made eruptive by Delesse, and metamorphic by some 
 later authors. Approaches argillyte in aspect. 
 
 9. Greisen.—Massive, without schistose structure. A mix- 
 ture of granular quartz and mica, in scales. ‘The mica may 
 be muscovite, lepidolite, or biotite. Itis a granite with the 
 feldspar left out, and occurs in regions of gneiss, granite, 
 or quartzyte, and sometimes graduates into these rocks. 
 Metamorphic. 
 
 Occurs in characteristic form at Zinnwald, in the Erzgebirge, where 
 it sometimes contains tin ore as an accessory ingredient, and is fre- 
 quently penetrated by veins of tin; also in the tin ore regions of 
 Schlackenwald and Cornwall. Occurs in the region of quartzyte, horn- 
 blendic rocks and gneiss, of Upper Silurian age, between Bernards- 
 ton, Mass., and Vernon, Vt., within three miles northeast of the former 
 place, and also near Vernon; but at this place it contains usually a 
 little hornblende, making it a very tough rock, and is intermediate 
 between the quartzyte, hornblendic rock and mica schist of the region. 
 
 10. Mica-Argillyte or Mica-Phyllyte.—Includes the part of 
 argillyte (p. 428) which has the composition nearly of a hy- 
 drous mica, like that of the White Mountain Notch, where 
 much of it is andalusitic. Analysis of this White Mountain 
 rock, by Hawes, afforded Silica 46°01, alumina 80°56, iron 
 sesquioxide 1°44, iron protoxide 6°85, manganese protoxide 
 
442 DESCRIPTIONS OF ROCKS. 
 
 0:10, magnesia 1°42, soda 1°12, potash 6°66, titanium dioxide 
 1:91, water 4°13=100-°22. (Compare with analyses of hy- 
 drous muscovite, or margarodite.) Metamorphic. 
 
 11. Felsyte. Quartz-Felsyte. (Zuryte, Petrosilex.)—Com- 
 pact orthoclase, with often some quartz intimately mixed; 
 fine granular to flint-like in fracture; sometimes contains 
 oligoclase. Colors white, orayish-white, red, brownish-red 
 to black. G.—2°6-2°7%. Both metamorphic and eruptive. 
 
 VARIETIES.—There are two sections, I. Felsyte, and Il. Quartz- 
 Felsyte, and under each occur the following varieties. a. Porphyritic 
 Felsyte, or Porphyry ; containing the feldspar in small crystals distri- 
 buted through the compact base ; color red and of other shades ; called 
 sometimes Quartz-porphyry, when the base is a quartz-felsyte. b. Con- 
 glomerate felsyte ; containing pebbles, as at Marblehead, Mass., and in 
 the White Mountains. c. Oligoclase-bearing ; containing this triclinic 
 feldspar intimately blended with the orthoclase. d. Cellular or amyg- 
 daloidal. e. Hlwanyte ; essentially a quartzose felsyte, of gray, bluish- 
 gray to brown and red colors, and often containing disseminated grains 
 or crystals of quartz and feldspar, and some oligoclase ; some compact 
 slate-rock has the same composition. Occurs in Cornwall. 
 
 The metamorphic and eruptive kinds are not easily distinguished. 
 The former occurs associated with sedimentary strata, and often con- 
 tains pebbles or other evidence of fragmental origin ; while the lat- 
 ter is frequently in dikes, that is, fills the fissures through which it 
 was ejected. Some of the eruptive felsyte has nearly the aspect of 
 trachyte, with which rock it is identical in composition. Much of the 
 red porphyry contains hornblende with the feldspar of the base, and 
 has the constitution of dioryte (p. 447). 
 
 12. Porcelanyte. (Porcelain Jasper.)—A baked clay, hav- 
 ing the fracture of flint, and a gray to red color; it is some- 
 what fusible before the blowpipe, and thus differs from 
 jasper. Formed by the baking of clay-beds, when they con- 
 sist largely of feldspar. Such clay-beds are sometimes baked 
 to a distance of thirty or forty rods from a trap dike, and 
 over large surfaces by burning coal beds. Metamorphic. 
 
 13. Trachyte. Quartz-Trachyte.—Consists mainly of feld- 
 spar, which is partly in glassy crystals, either sanidin or 
 oligoclase ; and, owing to the angular forms of the glassy 
 feldspar and the porosity of the rock, the surface of frac- 
 ture is rough, whence the name from the Greek ¢rachus, 
 rough. Sometimes contains disseminated quartz, and is 
 then quartz-trachyte. Color ash-gray, greenish-gray, brown- 
 ish-gray, but sometimes yellowish and reddish. G.=2°5- 
 2-7, Besides the feldspar there are distributed, somewhat 
 sparingly, through the mass, in many kinds, minute needles 
 of hornblende, crystals or scales of biotite, magnetite; some- 
 
KINDS OF ROCKS. 443 
 
 times nephelite, hatiynite, tridymite. Apatite exists in the 
 rock in microscopic forms, and there is also more or less of 
 the rock in a glassy state. Sometimes contains augite, and 
 has a higher specific gravity. Quartz-trachyte has often 
 nearly the composition of granite in which there is httle 
 mica. Hruptive only. , 
 
 VARIETIES.—The two principal divisions under each, trachyte and 
 quartz-trachyte, are: A. Sanidin-trachyte, in which the mass is chiefly 
 sanidin ; and B. Oligoclase-trachyte, or Domyte, in which it is partly 
 oligoclase ; but the two graduate into one another. Both occur por- 
 phyritic with tabular crystals of feldspar ; and in the latter (as at 
 the Drachenfels) the tables are sanidin. They graduate into vesicular 
 or scoriaceous trachyte. 
 
 Trachyte, according to Reyer and Suess, occurs in the region of the 
 Euganean Hills of Tertiary, Cretaceous and Jurassic age; and the 
 felsyte of Paleozoic age is often hardly distinguishable from it, while 
 identical with it in composition. 
 
 Trachyte and quartz-trachyte graduate also into felsyte-like volcanic 
 rocks of like constitution, porphyritic or not so. The latter sometimes 
 shades into rocks of semi-glassy nature called 
 
 14. Pearlstone, when somewhat pearly in lustre; PITCHSTONE 
 when having a pitch-like lustre; and these into the glassy 
 volcanic material called Obsidian. These glassy rocks often 
 contain spherules which are concretions consisting of feld- 
 spar with some quartz. Pumice is a light, porous, feldspa- 
 thic scoria, with the pores capillary and parallel. Ordina- 
 ry obsidian, that consists chiefly of feldspar, and is hence 
 nearly free from iron, belongs here; the rest of it belonging 
 with the augitic igneous rocks. 
 
 15. Leucityte.—A grayish rock consisting chiefly of leucite 
 inafelsitic state, with disseminated leucite crystals. Occurs 
 at Point of Rocks, Wyoming Territory, according to King 
 and Zirkel. It differs from amphigenyte, in containing no 
 pyroxene, or only traces of it. 
 
 8. MICA AND SODA-LIME-FELDSPAR ROCKS. 
 I. NOT CONTAINING NEPHELITE. 
 
 1. Kersantyte.—Fine-graincd ; consists of biotite and white 
 oligoclase, with some quartz, and frequently some horn- 
 blende in needles, and magnetite ; sometimes porphyritic. 
 Analysis afforded Delesse 58:0 per cent. of silica, and_ 63°88 
 of silica for the oligoclase. From Visembach and St. Marie- 
 aux-Mines in the Vosges, the Saxon Erzebirge, and Nassau. 
 
444 DESCRIPTIONS OF ROCKS. 
 
 Kersanton is a similar rock, from near Brest, and from Quimper in 
 Brittany, where it is used for buildings. It contains no hornblende, 
 and affords about 53 per cent. of silica. Both have been called mica- 
 dioryte (Glimmer-Diorite), although not hornblendic rocks. (See page 
 
 425.) 
 
 2, Kinzigyte.—Granular-crystalline to compact and schis- 
 tose ; consists of biotite, oligoclase, garnet, without quartz, 
 and contains, as accessories, microcline, iolite, and fibro- 
 lite. Affords in analyses about 44°5 per cent. of silica. 
 From Kinzig, north part of Black Forest. 
 
 II. CONTAINING NEPHELITE. 
 
 1. Miascyte—Granitoid to schistose, and consisting of 
 microcline, massive nephelite (eleolite), sodalite, biotite, 
 along with some quartz, and often some zircon, pyrochlore, 
 monazite and other minerals. A related nephelite rock oc- 
 curs on Pic Island, Lake Superior. Named by G. Rose, 
 from Miask in the Ilmen Mountains, where it has a wide 
 distribution. Metamorphic. 
 
 2. Ditroyte—A coarse to fine-grained rock, consisting of 
 microcline, nephelite (eleolite), and sodalite. From Ditro in 
 Hastern Transylvania, where it is associated with syenyte 
 and mica schist and lies between these two rocks. 
 
 3. Phonolyte. (Clinkstone.)—Compact ; of grayish, blue, 
 and other shades of color ; more or less schistose or slaty in 
 structure; tough, and usually clinking under the hammer, 
 like metal, when struck, whence the name. G,=2:4-2°7, 
 Consists of glassy feldspar (orthoclase or oligoclase), with 
 nephelite and some hornblende. G. Jenzsch gives, for the 
 composition of the Bohemian phonolyte, Sanidin (glassy or- 
 thoclase) 53°55, nephelite 31°76, hornblende 9°34, sphene 3°67, 
 pyrite 0°04=98-°36. Under treatment with acids the nephe- 
 lite is dissolved out. Nosean and haitynite occur in some 
 phonolyte. Eruptive only. 
 
 4, HORNBLENDE AND POTASH-FELDSPAR SERIES. 
 
 In this series the hornblende is sometimes replaced by 
 epidote, another anhydrous iron-bearing mineral, yielding 
 on analysis little or no alkali ; microcline is often present 
 as well as orthoclase. The species graduate into kinds con- 
 sisting almost solely of hornblende. Biotite is often pres- 
 ent as an accessory mineral, 
 
. KINDS OF ROCKS. 445 
 
 I. NOT CONTAINING NEPHELITE. - 
 
 1, Syenyte. Quartz-Syenyte.—A granitoid rock consisting 
 of hornblende and orthoclase, with or without quartz. 
 Some oligoclase is often present. ‘The quartziferous va- 
 riety, or guartz-syenyte, includes the syenyte of the obe- 
 lisks and pyramids of Egypt. like that, the rock is often 
 flesh-colored ; but whitish and grayish varieties are also 
 common. ‘The Saxon syenyte, without quartz, afforded 
 Silica 59°83, alumina 16°85, iron protoxide 7-01, lime 4°43, 
 magnesia 2°61, potash 6°57, soda 2°44, water 129, aes = 
 9-75-2°90. Metamorphic and eruptive. Similar varieties 
 occur under both divisions of syenyte. 
 
 Varretins.—a. Porphyritic. b. Albitic ; containing albite in addi- 
 tion to the constituents of true syenyte. c. Oligoclase-bearing. d. Mi- 
 caccous ; containing disseminated black mica, which is usually bio- 
 tite, and sometimes lepidomelane. e. Garnetiferous. 1. Hpidotic ; 
 containing disseminated epidote. The gray ‘‘granite” of Quincy, 
 Massachusetts, south of Boston, extensively quarried for architectural 
 purposes, is a quartz-syenyte, consisting of orthoclase, black to dark 
 green hornblende, and quartz, with some triclinic feldspar. Quartz- 
 syenyte occurs also in the Frankenstein Cliff, five miles south of 
 White Mountain Notch; also in Mount Chocorua, N. H. ; in the Ar- 
 chean of Canada, at Grenville, a red kind containing very little quartz, 
 and a similar rock on Barrow Island, St. Lawrence, but containing 
 much quartz and little hornblende. Syenyte without quartz is a rare 
 rock in Eastern North America. It occurs in Nevada. 
 
 The name Syenites is used for this rock by Pliny, who adds that it 
 was also called ‘‘pyrrhopecilon ’—this appellation, meaning fire-red 
 variegated, referring to its being brightly spotted with rose-red. The 
 quarries in the vicinity of Syene (the modern Assouan), whence the 
 Egyptians obtained this stone for their obelisks, columns, statues, 
 sphinxes, sarcophagi, and the lining of their pyramids, are of great 
 extent ; and in one of them there is an unfinished obelisk in its origi- 
 nal position. They are situated to the south of Syene, and between 
 that place and the island of Philoe. The rock consists chiefly of red 
 feldspar and grayish quartz, with oligoclase, some black hornblende, 
 and a little black mica. An analysis by Delesse obtained Silica 
 70°25, alumina 16-00, iron oxide with some manganese 2°50, lime 1°60, 
 expelled on ignition 4°65, magnesia and alkalies by loss 9:00=100. 
 More remote from Syene the rock loses its hornblende and becomes 
 a granite. 
 
 The Scotch syenyte, so much used for monuments, is quartz-syenyte. 
 It occurs both red and dark gray, and the former is closely like the 
 Egyptian syenyte. 
 
 Werner applied the name ‘‘syenyte” to the quartzless syenyte of 
 Plauenschen-Grunde, Saxony, an analysis of which is given above (a 
 rock he afterwards called ‘‘greenstone”). G. Rose used the term for 
 the quartz-syenyte. Other German lithologists have followed Werner, 
 calling the quartz-syenyte, hornblende-granite. It seems best to draw 
 
446 DESCRIPTIONS OF ROCKS. 
 
 the line between the mica-bearing and the hornblendc-bearing rocks, 
 as here done, and to use the name syenyte for the rock to which it was 
 originally applied, as well as for the quartzless kinds. -- ~ 
 
 2, Syenyte-gneiss.—Like gneiss in aspect and schistose 
 structure; and also in constitution, except that horn- 
 blende replaces mica. Occurs both with and without 
 quartz, though usually quartz-bearing. ‘The varieties are 
 nearly the same as under syenyte. Metamorphic. 
 
 3. Hornblende schist.— A schistose rock consisting of horn- 
 blende, with usually more or less quartz, but sometimes 
 almost wholly hornblende. Frequently contains epidote, 
 garnet, magnetite. Metamorphic. 
 
 4. Amphibolyte.—A very tough, granular-crystalline rock, 
 consisting of hornblende, and hardly schistose in structure. 
 Color, greenish-black to black. Metamorphic. 
 
 A Glaucophanitic variety consists chiefly of the blue soda-hornblende, 
 
 called glaucophane, with usually some black mica. From Saxony 
 Isle of Syra, New Caledonia. 
 
 5, Actinolyte—A tough, massive rock made chiefly of 
 actinolite. Grayish green. Metamorphic. 
 
 6. Unakyte.—A flesh-colored granitoid rock consisting of 
 orthoclase, quartz,and much yellowish-green epidote. From 
 the Unaka Mountains, North Carolina, and East Tennessee. 
 
 II. CONTAINING NEPHELITE. 
 
 1, Zircon-Syenyte.—A crystalline granular rock consisting 
 of orthoclase, microcline, little hornblende, crystals of zir- 
 con, and some eleeolite. 
 
 2. Foyayte.—Coarse crystalline, granular to compact; 
 consists of orthoclase, reddish-brown nephelite (eleolite), in 
 six-sided prisms, and blackish-green hornblende. Occurs 
 also porphyritic, and passes into an aphanitic variety. From 
 Mt. Foya and Picota, in the Province Algarve, in Portugal. 
 ee (p. 444) is related, but contains very little horn- 
 
 ende. 
 
 , 5. HORNBLENDE AND SODA-LIME-FELDSPAR SERIES. 
 
 I. NOT CONTAINING SAUSSURITE IN PLACE OF THE — 
 FELDSPAR CONSTITUENTS. 
 
 1. Dioryte. Quartz-Dioryte. (Greenstone in part.)—The 
 triclinic feldspar, one of the acidic (rich in silica) species, 
 
KINDS OF ROCKS. 44% 
 
 albite or oligoclase. Texture granitoid to fine-grained or 
 compact. Color often grayish-white to greenish-white for 
 the coarser kinds; olive-green to blackish-green for the 
 finer. Very tough. G.=2°7-3°0. The guartz-bearing and 
 qguartz-less kinds constitute two sections having similar va- 
 rieties. Dark-red, brownish-red, and dark-green porphy- 
 ritic kinds, compact in base, have been called porphyryte. 
 Metamorphic and eruptive. 
 
 VARIETIES.—a. Granitoid ; granite-like in texture. b. Compact 
 or fine-grained, with the feldspar grains scarcely distinguishable. 
 c. Porphyritic ; the feldspar in crystals in a compact base. d. Slaty ; 
 a dioryte slate or schist, usually chloritic. e. Micaceous. f. Apha- 
 nitic (or Aphanite) ; nearly flint-like in texture. 
 
 An analysis of a dioryte of the Hartz afforded Silica 5465, alumina 
 15°72, iron sesquioxide 2°00, iron protoxide 6°26, manganese protoxide 
 trace, magnesia 5°91, lime 7°88, potash 38°79, soda 2°90, water and ig- 
 nition 1:90=100°96. 
 
 The antique red porphyry, or ‘‘rosso antico,” figured on page 415, 
 is an example of porphyritic dioryte. The crystals, according to the 
 analysis of Delesse, are oligoclase, and have G.=2°67, while the base 
 has G.=2°765, it consisting of an intimate mixture of oligoclase and 
 hornblende, with some grains of iron oxide. For the whole mass, accord- 
 ing to Delesse, G.=2.763, but after fusion, only 2°486. Distinct acicu- 
 lar crystals of hornblende occur in it. The rock is sometimes a brec- 
 cia, being made up of angular fragments, either quite distinct from the 
 mass or else shading off into it, but all alike porphyritic. The Mt. 
 Dokhan, in which it occurs —‘‘ Porphyrites mons” of Ptolemy—con- 
 tains also red syenyte similar to that of Syene, and a coarse red gran- 
 ite. The ‘“porphyrite” of Ilfeld, of Schénau in Bohemia, and the 
 « quartz-porphyrite ” of Koliwansk in the Altai are here referred. 
 
 Propylyte and quartz-propylyte have the same constitution. The 
 former is the prevailing igneous rock of the Washoe district (vicinity 
 of the Comstock lode), in Nevada; it is a grayish-green rock, yield- 
 ing, on analysis, 64 to 66 per cent. of silica, and containing, along 
 with oligoclase, hornblende, disseminated in minute points, and rarely 
 also biotite (Zirkel). 
 
 Ophite, of the Pyrenees, is greenish-black dioryte. 
 
 9. Andesyte. Quartz-Andesyte—Contains the feldspar an- 
 desite along with hornblende. As in the preceding, the 
 hornblende is sometimes changed to chlorite. Qwartz-an- 
 desyte, or Dacyte, is a quartz-bearing variety. Both kinds 
 occur in the Washoe district. Eruptive. Also metamorphic? 
 
 Banatite and Tonalite are like quartz-dioryte in most characters, 
 but have the feldspar the species andesite. Each contains some bio- 
 tite, the latter much of it. Banatite is from the Banat, and Tonalite 
 from near Tonale, in the Southern Alps. 
 
 Trachydoleryte (of Abich), a dark gray to reddish-brown rock, some- 
 what trachyte-like in aspect, is, in part, near andesyte, it consisting of 
 
448 DESCRIPTIONS OF ROCKS. 
 
 oligoclase or andesite and hornblende, with G.=2-73—2'80, and afford. 
 ing 55 to 61 per cent. of silica ; it occurs in the Peak of ‘l'eneriffe, on 
 Liscanera I. near Stromboli, and on some parts of Etna. Another rock 
 included under this name, found at Stromboli, Rocca Monfina, and 
 Tunguragua in Quito, contains augite in place of hornblende, with 
 oligoclase or labradorite, and is near doleryte. A third rock described 
 under this name by Ludwig is augitic trachyte, the feldspar being 
 sanidin. Trachyte graduates into andesyte, augite-andesyte, doleryte, 
 as well as granite. 
 
 8, Labradioryte. (Labradorite-Dioryte, Greenstone in part. ) 
 —The feldspar one of the basic (poor in silica) species, la- 
 bradorite or anorthite. Texture usually fine-grained, some- 
 times crypto-crystalline. Color light grayish-green to dark 
 olive-green, blackish-green or gray, and sometimes black. 
 Very tough. G.=2'8-3-1. Often contains chlorite and 
 magnetite. Often has associated with it beds of serpentine 
 or ophiolyte. Metamorphic and eruptive. 
 
 VARIETIES.—a. Granular crystalline. b. Compact, or fine-grained ; 
 of dark green color; constituent minerals not distinct. ¢. Porphyri- 
 tic ; the feldspar in whitish or greenish-white crystals disseminated 
 through a fine-grained base, making a greenish “‘porphyry ;” its 
 crystals sometimes anorthite. d. Pyroxenic ; containing some dissem- 
 inated pyroxene. e. Magnetitic ; containing magnetite or titanic iron. 
 Occurs in the Urals ; to the west of New Haven, Conn., both massive 
 and porphyritic ; in Littleton, N. H. A porphyritic variety of the 
 rock near New Haven—a metamorphic rock—afforded Hawes, Silica 
 48°61, alumina 17°81, iron sesquioxide 0°25, iron protoxide 8°46, man- 
 ganese protoxide 0:20, lime 11°16, magnesia 7-76, soda 2°77, potash 
 0:47, water 1°63, titanium dioxide 1:35=100°47; G.=3°01. A com- 
 pact non-porphyritic variety from the same formation, collected on 
 Stoeckel’s farm, afforded Hawes, Silica 50°36, alumina 14°57, iron ses- 
 quioxide 2°48, iron protoxide 8°31, manganese protoxide 0°46, magne- 
 sia 7°62, lime 11°18, soda 3°04, potash 0°44, water 0°78, titanium diox- 
 ide 1°70, chromium oxide 0°78=100°89 ; G.=8°04._ The crystals of the 
 porphyritic variety, according to an imperfect analysis by E. S. Dana, 
 consist of anorthite. 
 
 4, Corsyte-—A granitoid rock, consisting chiefly of anor- 
 thite and hornblende, with some quartz and biotite. From 
 Corsica. 
 
 Teschenite is bluish-green, and chiefly consists of anor- 
 thite, hornblende, and augite, the hornble de sometimes in 
 large black prisms ; also contains analcite. J*rom Teschen, 
 Austria. 
 
 5. Isenite—Contains a triclinic feldspar and hornblende, 
 with much nephelite and nosean, and some magnetite. 
 From the Hisbach (Isena) district in the Westerwald, West 
 Germany. 
 
KINDS OF ROCKS. 449 
 
 II, SAUSSURITE-BEARING. 
 
 6. Euphotide. (Gaddro in part.)—A grayish-white to gray- 
 ish-green, and sometimes olive-green rock, very tough, having 
 G.=2'9-3°4. Consists of saussurite of whitish to greenish 
 and bluish color, mixed either with smaragdite of emerald- 
 green color, or with green to grayish-green diallage; the 
 diallage generally containing more or less hornblende, and 
 the smaragdite, pyroxene. The saussurite is commonly of 
 either the first or second kind mentioned on page 410; but 
 the distribution of these kinds is not fully made out. Labra- 
 dorite is rarely present locally in place of the saussurite, 
 Metamorphic. 
 
 VARIETIES.—a. Diallagic; diallage the chief foliated mineral. b. 
 Smaragdaitic ; emerald-green smaragdite, the foliated mineral. c. Jf- 
 caceous ; contains mica. d. Serpentinous ; contains some serpentine— 
 a rock into which it often graduates. e. Garnetiferous. f. Schistose ; 
 especially so when tale is present. g. Variolitic; contains aphani- 
 tic concretionary spheroids of the saussurite mineral, asin the ‘‘ Vario- 
 lite de la Durance,” and of Mt. Genévre, and asociated with ordinary 
 euphotide ; for which concretions Delesse obtained the composition 
 Silica 56°12, alumina 17°40, chromium oxide 0°51, iron protoxide 7°79, 
 magnesia 3°41, lime 8°74, soda 3°72, potash 0:24, ignition 1:93=99-86, 
 and the specific gravity 2°923. The variety obtained at Orezza is the 
 Verde di Corsica, of decorative art. 
 
 Occurs near Lake Geneva, in Savoy ; at Mt. Genévre in Dauphiny, 
 near the boundary between France and Italy ; at Allevard, in the 
 northeastern part of Isére ; in the valley of the Saas, north of east of 
 the Monte Rosa region ; in the Grisons ; near Leghorn and Bologna ; 
 near Florence, at Mt. Impruneta, it being the Granitone (page 450) 
 of the Serpentine region ; on Corsica, in the Orezza valley; in Silesia ; 
 in I. of Unst. It is often associated with serpentine ; and the serpen- 
 tine and euphotide form beds in irregular masses among, and as a 
 constituent part of, a series of metamorphic strata, which include 
 green chloritic and talcose schists, limestone (which, at Mt. Genévre, 
 is of the Jurassic formation), and other rocks. For the Mt. Genévre 
 euphotide, Delesse obtained Silica 45-00, alumina and iron oxide 
 26°83, lime 8°49, magnesia, soda and potash (by loss) 13:90, water 
 and carbonic acid 6°78, and for the saussurite the result stated on 
 page 410. The composition is near that of a labradioryte, and the dif- 
 ference in the two rocks must have depended on the different condi- 
 tions attending crystallization. The mixture of hornblende and py- 
 roxene in either foliated constituent, in connection with their mutual 
 positions and structure, proves that part of the hornblende is altered 
 pyroxene, The remark made on page 410 with reference to the pro- 
 duction of the saussurite may apply also to the foliated hornblende, 
 and therefore to the whole rock. os 
 
450 DESCRIPTIONS OF ROCKS. 
 
 6. PYROXENE AND SODA-LIME-FELDSPAR SERIES. 
 
 1, Augite-Andesyte—Contains the same triclinic feldspar 
 as andesyte, but augite is present 1n place of hornblende. 
 Amount of silica obtained in analyses about 55 to 58 per 
 cent. ‘Texture crystalline-granular to aphanitic ; colors dark 
 gray to greenish-black and brownish-black, G.= 2°65—2°90. 
 Hruptive. 
 
 VARIETIES.—There are two series: A. Ordinary, that is, without 
 chrysolite, or only in traces. B. Chrysolitic, chrysolite being in 
 disseminated grains or crystals. Under each there are varieties : 
 a. anhydrous ; b. hydrous, or chioritic, and feeble in_ lustre ; and 
 c. amygdaloidal, as well as chioritic. Again, each of these varieties 
 may be porphyritic. To the hydrous rock, and especially the chryso- 
 litic, the term Melaphyre is sometimes applied. 
 
 Quarte-Augite-Andesyte is described by Zirkel as occurring in Pali- 
 sade Cafion, in Nevada Plateau ; it contains yellowish-brown augite, 
 some biotite, some grains of quartz. Silica 62-71 per cent. 
 
 2. Noryte. (Hyperyte, Hypersthenyte.)—A basic granitoid 
 rock in part, consisting of cleavable labradorite with dis- 
 seminated pyroxene, or a granular crystalline aggregate of 
 the two minerals. ‘Che pyroxene is often foliated, and has 
 been improperly called hypersthene. In place of labrador- 
 ite, the feldspar is sometimes andesite, and sometimes anor- 
 thite. Color, dull flesh-red to brownish-red, also dark-gray, 
 to grayish-black. Tough. G.=2-7-3°1, varying with the 
 proportion of pyroxene, which is sometimes small. Con- 
 tains also magnetite or titanic iron. 
 
 The name Gabbro has been applied to this rock ; also to a coarsely 
 granular igneous rock, consisting chiefly of labradorite and foliated 
 pyroxene, referred beyond to doleryte ; to euphotide ; and, by the 
 Iialians, formerly to serpentine. Ferber, in his ‘‘ Briefe” (1778), says 
 (p. 98): Gabbro of Florence is the same as the rock called << sichsi- 
 schen Serpentin, in Deutschland,” that is, the serpentine of Zéblitz. 
 Again, on page 330, he says that Mt. Impruneta, seven Italian miles 
 from Florence, consists of Gabbro, or the so-called Saxon serpentine, 
 and he alludes to the occurrence in it of diallage and amianthus, and 
 the presence also ‘‘ der sogenannte Granitone ” ‘‘ in horizontalen 
 Schichten in den Gabbro-Bergen,” which sometimes consisted “‘ aus 
 weissem Feldspat, welcher grosse Parallelepipeden formirte,” though 
 usually containing diallage. 
 
 VARIBTIES.—a. Granitoid ; the feldspar in distinct cleavable grains 
 ormasses. b. Feldspathose ; the pyroxene feeble in amount. c. Chry- 
 solitic ; contains disseminated chrysolite. d. Anorthitic, or Tractolite ; 
 anorthite replaces the labradorite. 
 
 Noryte includes the so-called hypersthenite of the Adirondacks, Can- 
 ada, and Norway. It occurs also in the Laramie Hills, Colorado, a 
 
KINDS OF ROCKS. 451 
 
 kind which afforded, on analysis, Silica 52:14, alumina 29:17, iron 
 oxide 3°26, magnesia 0°76, lime 10°81, soda 3:02, potash 0°98, ignition 
 0:°58=100°92. 
 
 3. Hypersthenyte.—A rock resembling the preceding, con- 
 sisting of cleavable labradorite with ¢trwe foliated hyper- 
 sthene; from St. Paul’s, Labrador, and some other localities. 
 
 4. Doleryte. (Basalt, Trap.)—Chief constituents, labra- 
 dorite and augite, with magnetite, and sometimes anorthite. 
 Often porphyritic, and the feldspar crystals may be anor- 
 thite. Amount of silica yielded on analysis usually 47 
 to 52 per cent. Texture crystalline-granular to aphanitic; 
 and often, especially in the latter, having glassy particles 
 among the crystalline, or even an unindividualized base 
 or magma between the crystalline grains—the variety called 
 Basalt ; often coarse granular through the body of a dike, 
 while aphanitic along its walls, and sometimes containing 
 glassy portions in the latter when not elsewhere. Colors 
 dark grayish to bluish-black, greenish-black, and brownish- 
 black. G.=2-75-3:1. Eruptive ; also metamorphic. 
 
 It includes the larger part of the rock usually called trap, abundant 
 in most regions of igneous eruptions ; constitutes the ‘‘ trap” ridges 
 of the Connecticut Valley, the Palisades of New Jersey, and similar 
 ridges in Nova Scotia and North Carolina; also in the Lake Superior 
 region, and extensive beds of so-called basaltic rocks over the Rocky 
 Mountain slopes west of the Front Range. The rock of New Haven, 
 Conn., from West Rock, afforded Silica 51°78, alumina 14:20, iron ses- 
 quioxide 3°59, iron protoxide 8°25, manganese protoxide 0°44, magne- 
 sia 7°63, lime 10°70, soda 2°14, potash 0°39, loss by ignition 0°68, phos- 
 phorus pentoxide 0'14=99°89; G.=3-03. A hydrous or chloritic variety 
 from Saltonstall’s Ridge, near New Haven, afforded Silica 49:28, 
 alumina 15°92, iron sesquioxide 1:91, iron protoxide 10°20, manganese 
 protoxide 0°37, magnesia 5-99, lime 7-44 soda 3°40, potash 0°72, water 
 3°90, carbon dioxide 1:14—100°72 ; G.=2°86. 
 
 VARIETIES.—There are two series: A. Ordinary, B. Ohrysolitic, 
 and for the latter the name Peridotyte has been used. Each occurs : 
 a. anhydrous ; b. hydrous, or chloritic, of feeble lustre ; c. amygda- 
 loidal, as well as chloritic; d. vesicular, or scoriaceous, as in doleritic 
 or basaltic lavas. Spilite is amygdaloid. 
 
 Again, each of these varieties may be porphyritic. Again, the augite 
 may be in distinct crystals. 
 
 A coarse-granular kind, having the pyroxene foliated, is sometimes 
 called gabbro. 
 
 This basic rock, doleryte, is often called, also, basalt, especially 
 when it has an unindividualized base ; a specimen of this kind, from 
 Nevada, is represented in fig. 7, page 418. The name, anamesite, 
 has been used for an aphanitic kind, but is unnecessary. The term 
 diabase is sometimes applied to dolerytes older than Tertiary. It was 
 formerly supposed that the former differed from the latter in being 
 
452 DESCRIPTIONS OF ROCKS. 
 
 chloritic, and afterwards in never containing glassy particles or an un- 
 individualized base ; but neither distinction holds. 
 
 The “‘ antique green porphyry,” or Porfido verde antico, figured on 
 page 415, in fig. 2, is a porphyritic rock of the composition of doleryte, 
 the feldspar being labradorite, and the other chief constituent, augite, 
 with also some chlorite, or viridite, which last is the source of the 
 greenish color. It is from the South Morea, between Lebetsova and 
 Marathonisi. Delesse obtained, from the compact base, Silica 53°55, 
 alumina 19°34, iron protoxide 7:35, manganese protoxide 0°85, lime 
 8:02, soda and potash 7:93, water 2°67. In view of its firmness, and 
 its contrast in this respect with most chloritic doleryte, it may be 
 queried whether the rock is not a metamorphic doleryte (metadoleryte). 
 It closely resembles the porphyritic labradioryte from the vicinity of 
 New Haven, Conn. (which is chloritic and metamorphic), though differ- 
 ing from it in containing pyroxene instead of hornblende. A similar 
 porphyry is reported from Elbingerode in the Hartz, Belfahy in the 
 Vosges, and Barnetjern near Christiania in Norway. ' 
 
 5. Eucryte.—A doleryte-like rock consisting chiefly of an- 
 orthite and augite. Occurs compact, and as a lava. “From 
 Elfdalen, Norway. 
 
 6. Amphigenyte. (Leucitophyre. )—Contains augite, like 
 doleryte, but leucite (called sometimes amphigene) replaces 
 the feldspar. Dark gray, fine-grained, and more or less cel- 
 lular to scoriaceous. G.=2°7-2:9. The leucite is dissemi- 
 nated in grains or in 24-faced crystals. Constitutes the 
 lavas of Vesuvius and some other regions. Accessory min- 
 erals, nephelite, biotite, chrysolite, sodalite, sanadin, labra- 
 dorite and nosean. ? 
 
 Hatiynophyre is an amphigenyte from Vulture, near Melfi, in whic 
 haiiynite replaces much of the leucite. 
 
 7. Nephelinyte. (Nepheline-doleryte. )—Contains augite, 
 like doleryte, but nephelite replaces the feldspar, or the larger 
 part of it. Crystalline-granular ; ash-gray to dark gray. 
 The nephelite is partly in distinct crystals. 
 
 8. Tachylyte. Hyalomelan.—Blackish glass, or pitchstone, 
 made in connection with augitic igneous rocks or lavas ; 
 ae former affords on analysis 49 per cent. of silica, and the 
 latter 55. 
 
 This Doleryte-pitchstone may be porphyritic, or contain small grains 
 of augite, or of chrysolite. 
 
 7%, PYROXENE, GARNET, EPIDOTE, AnD CHRYSOLITE ROCKS, 
 CONTAINING LITTLE on NO FELDSPAR. 
 
 1. Pyroxenyte.—Coarse or fine granular pyroxene rock. 
 2, Garnetyte, or Garnet Rock—A yellowish-white to green- 
 
_ KINDS OF ROCKS. 453 
 
 ish-white, tough rock, consisting of an alumina-lime garnet. 
 G.=3°39-3°49. From St. Francis, Canada. The superior 
 yellow novaculite or whetstone, of Vieil Salm, Belgium, has 
 the constitution, according to A. Renard, of a manganesian 
 garnet. Metamorphic. | 
 
 3. Eclogyte——Compact and tough. Consists of granular 
 garnet and hornblende, with grass-green smaragdite. G.= 
 3°2-3°5. <A related rock consists of reddish or brownish- 
 yellow garnet, and black or greenish-black hornblende, with 
 often some magnetite. Metamorphic. 
 
 4, Epidosyte.—Pale green to pistachio-green. Consists of 
 epidote mixed with quartz. Metamorphic. 
 
 5. Eulysyte.—Fine-granular, consisting of chrysolite with 
 a diallage-like mineral and garnet. Forms a bed in gneiss 
 near T'unaberg, Sweden. 
 
 6. Chrysolyte, or Chrysolite-Rock.— Yellowish to pale olive- 
 green, granular; consisting almost wholly of chrysolite. 
 G.=3-3°1; H.=5°5-6. Abundant in Macon County, N. 
 Carolina; in part changed to serpentine. Metamorphic. 
 
 Dunyte is yellowish-green ; granular, and consists of chrysolite, with 
 some chromite. From Mount Dun, New Zealand. Eruptive. 
 
 7, Lherzolyte.—Greenish-gray ; crystalline granular. Con- 
 sists of chrysolite, enstatite, whitish pyroxene, with chrome- 
 spinel and sometimes garnet. From Lake Lherz, etc. Is 
 it metamorphic ? 
 
 8. Picryte.—Blackish-green to brownish-red ; crystalline- 
 granular. Consists of chrysolite, with augite sometimes in 
 crystals. Graduates into chrysolitic doleryte. 
 
 9, Limburgyte.—A semi-glassy rock, consisting of chryso- 
 lite and augite, with some magnetite. It is occasionaily 
 amygdaloidal. Affords on analysis 43 per cent. of silica. 
 
 8. HYDROUS MAGNESIAN AND ALUMINOUS ROCKS. 
 
 Contain one or more of the hydrous magnesian minerals, 
 chlorite, tale, serpentine, or the related hydrous aluminous 
 mineral, pyrophyllite. ‘The fine-grained kinds are more or 
 less greasy to the touch ; and some of them resemble the 
 hydromica slates. 
 
 1. Chlorite Schist.—Schistose ; color dark green to grayish- 
 green and greenish-black ; but little, if any, greasy to the 
 touch. Consists of chlorite, with usually some quartz and 
 
454 DESCRIPTIONS OF ROCKS. 
 
 feldspar intimately blended, and often contains crystals 
 
 (usually octahedrons) of magnetite, and sometimes chlorite 
 
 in distinct scales or concretions. Metamorphic. 
 VARIETIES.—a. Ordinary. b. Hornblendic ; the hornblende in grains 
 
 or needles. c. Magnetitic. d. Towrmalinic. e. Garnetiferous. f. Pyr- 
 ovenic. g. Staurolitic. h. Hpidotic. Graduates into argillyte. 
 
 2. Chlorite-Argillyte—An argillyte or phyllyte consist- 
 ing largely of chlorite. Metamorphic. 
 
 3 Talcose Schist.—A slate or schist consisting chiefly of 
 tale. Not common, except in local beds, most of the so- 
 called <talcose slate” being hydromica schist (p. 440). 
 
 4. Steatyte, Soapstone (p. 55).—Consists of tale. Mas- 
 sive, more or less schistose ; granular to aphanitic. Color, 
 gray to grayish-green and white. Feels very soapy. Lasily 
 cut with a knife. Metamorphic. 
 
 VARIETIES.—a. Coarse-granular, and massive or somewhat schis- 
 tose. b. Fine-granular; ‘French chalk.”  ¢. Aphanitic, or hens- 
 selaerite; of grayish-white, greenish, brownish to black colors, from 
 St. Lawrence County, N. Y., and Grenville, Canada. 
 
 5, Serpentine —Aphanitic or hardly granular ; of dark- 
 green to greenish-black color, easily scratched with a knife, 
 and often a little greasy to the feel on a smooth surface. 
 Although generally dark green, it is sometimes pale grayish 
 and yellowish-green, and mottled. Metamorphic. | 
 
 Varieties.—a. Woble; oil-green and translucent. b. Common, opaque, 
 and of various colors. c: Schistose. d. Diallagic ; contains green or 
 metalloidal diallage. e. Chromiferous; contains chromite, a chromium 
 ore belonging to serpentine regions. f. Bastitic ; contains bastite or 
 enstatite. g. Garnetiferous ; contains garnet, as at Zoblitz. h. Chry- 
 solitic ; contains chrysolite. i. Brecciated ; consists of united frag- 
 ments. (See also page 808.) Serpentine has been made by the altera- 
 tion of chrysolite beds, and of chondrodite and other magnesian sili. 
 cates. A rock consisting of serpentine and saussurite is true Gabbro. 
 
 6, Ophiolyte (Verd-Antique Marble).—-A mixture of ser- 
 pentine with limestone, dolomite, or magnesite, having a 
 mottled green color. Often contains disseminated magne- 
 tite or chromite. Metamorphic. 
 
 VARIETIES.—a. Calcarcous ; the associated carbonate being calcite. 
 b. Dolomitic ; the associated carbonate, dolomite. c. Magnesitic ; the 
 associated carbonate, magnesite. Hither of these kinds may contain 
 chromite or magnetite. Handsome verd-antique marble has been ob- 
 tained near New Haven and Milford, Conn. A beautiful variety, hav: 
 ing pure serpentine disseminated in grains or spots through a whitish 
 calcite, occurs at Port Henry, Hssex County, N. Y., and is worked. 
 
KINDS OF ROCKS. 455 
 
 7, Pyrophyllyte and Pyrophyllite Slate.— Like the preced- 
 ing in appearance and soapy feel, but having the composi- 
 tion of pyrophyllite (p. 306). The color is white and gray 
 or greenish white. Occurs in North Carolina. One of the 
 varieties from the Deep River region is used for slate pen- 
 cils. Metamorphic. 
 
 9. IRON-ORE ROCKS. 
 
 1. Hematyte. (Specular Iron Ore).—Hematite (p. 176), in 
 metamorphic beds. Color iron gray, and lustre bright me- 
 tallic, but varying to red and jaspery. Has the hardness of 
 crystallized hematite and its red streak. Constitutes beds 
 of great thickness in Archean regions and thinner beds in 
 formations of later geological age; alternates with horn- 
 blendic, chloritic, micaceous, and gneissoid, and sometimes 
 calcareous rocks, and often contains siliceous or jaspery 
 layers. 
 
 VARIETIES.—a. Jvon-gray; the ordinary massive kind. b. Red ; 
 resembling a hard red jasper, into which it sometimes passes. c. Con- 
 taining martite; the octahedral crystals of martite having originally 
 been magnetite, and showing that they are changed to hematite by 
 their red streak. d. Foliated ; sometimes called micaceous iron ore, 
 in allusion to the foliation. e. Hpidotic. 
 
 In large beds in the Archean of Canada, St. Lawrence Co., N. Y., 
 at Marquette, Northern Michigan, Missouri. At Nictaux, in Nova 
 Scotia, in semi-metamorphic fossiliferous Devonian there is a bed six 
 feet thick. 
 
 2. Itabyryte.—A mica schist consisting largely of hema- 
 tite in lamine of bright metallic lustre. 
 
 3. Magnetyte. (Magnetic Iron Ore).—Magnetite (p. 178), 
 in metamorphic beds. Color iron gray to grayish black, 
 and lustre metallic; never bright red. Strongly attracted 
 by the magnet, and hence often separated from the gangue, 
 after crushing it, by means of large electro-magnets. Con- 
 stitutes, like hematite, thick beds in Archean regions, and 
 thinner in rocks of other periods. 
 
 VARIETIES.—a. Massive. b. Granular. c. Epidotic. d. Hornblendic. 
 e. Ohloritic. f. Titanic. g. Ohondroditic ; as near Brewster, N. Y., 
 where chondrodite is the ‘‘ gangue” of the ore. 
 
 Metamorphic magnetite constitutes thick beds in the Archean of 
 Canada, Northern New York, Orange Co., N. Y., Sussex Co., N. J., 
 and occurs also in Virginia, east of the Blue Ridge, in Albermarle, 
 
456 DESCRIPTIONS OF ROCKS. 
 
 Essex, and Nelson counties, and elsewhere. Formsasmall bed in the 
 Upper Silurian of Bernardston, Mass., and in Devonian, at Moose River, 
 in Nova Scotia. 
 
 4, Menaccanyte. (Titanic Iron Ore).—Resembles massive 
 hematite, but consists chiefly of titanic iron (p. 178). Oc- 
 curs in the Archean of Canada, as in the parish of St. Ur- 
 bain, at Bay St. Paul, where the bed is ninety feet thick. 
 
 5. Franklinyte—Resembles massive magnetite, but con- 
 sists of franklinite (p. 179), which differs from magnetite in 
 containing more or less zinc and manganese. 
 
 Occurs at Mine Hill, in Hamburg, N. J., and also at Stirling Hill, in 
 the same region, constituting a bed of great thickness, It is mixed 
 with zinc ores, zincite and willemite, besides other minerals, and asso- 
 ciated with granular limestone, in an Archean region of hornblendic 
 and gneissoid rocks. 
 
 For non-metamorphic kinds of iron ores, see under HEMATITE 
 (p. 176), LrmoNITE (p. 181), and SIDERITE (p. 185). Beds of magne- 
 tite occur only in metamorphic regions, 
 
GENERAL INDEX. 
 
 Acadialite, 300. 
 Acanthite, 118. 
 Acmite, 247. 
 
 Actinolite, 249. 
 Actinolyte, 446. 
 Adamantine spar, 193. 
 Adamite, 156. 
 Adularia, 278. 
 Aigirine, Aigyrite, 247. 
 AEschynite, 202, 260. 
 Agalmatolite, 306, 312. 
 Agate, 236. 
 
 Aikinite, 136, 149. 
 Akanthit, v. Acanthite. 
 Alabandite, 188. 
 Alabaster, 210. 
 Albertite, 326. 
 
 Albite, 2777. 
 Alexandrite, 196. 
 Algodonite, 135. 
 Alipite, 168. 
 
 Alisonite, near Covellite, 133. 
 Allanite, 203, 263. 
 Allemontite, 101. 
 Allopalladium, 127. 
 Allophane, 296. 
 Allophite, 318. 
 Alluaudite, 191. 
 Alluvium, 429. . 
 Almandin, Almandite, 257. 
 Altaite, 149. 
 
 Alum, native, 198. 
 Alum shale, 428. 
 
 Alum stone, 198. 
 Aluminite, 199. 
 
 Aluminum, Compounds 192. 
 
 fluorides, 197. 
 Alunite, 198. 
 Alunogen, 197. 
 Amalgam, 117, 128. 
 Amazonstone, 278. 
 
 tw 
 
 Amber, 825. 
 Amblygonite, 44, 199. 
 Ambrite, 325. 
 Amethyst, 235, 289. 
 Oriental, 198. 
 Amianthus, 250, 308. 
 Ammonium alum, 198, 231. 
 Ammonium, Salts of, 230. 
 Amphibole, 249. 
 Amphibolyte, 446. 
 Amphigene, 271. 
 Amphigenyte, 452. 
 Amygdaloid, 418, 451. 
 Analcite, Analcime, 69, 299. 
 Anatase, 451. 
 Anamesite, 163. 
 Ancramite, 159. 
 Andalusite, 284. 
 Andesine, Andesite, 276. 
 Andesyte, 447. 
 Andradite, 258. 
 Andrewsite, 185. 
 Anglesite, 150. 
 Anhydrite, 211. 
 Ankerite, 186, 220. 
 Annabergite=Nickel arsenate. 
 Annite, 266. 
 Anorthite, 44, 275. 
 Anthophyllite, 252. 
 Anthracite, 327. 
 Anthraconite, 217. 
 Antigorite, 308. 
 Antillite, 309. 
 Antimonate, Calcium, 214. 
 Copper, 189. 
 Lead, 152. 
 Antimonial copper ores, 135, 106. 
 lead ores, 149. 
 nickel ores, 166. 
 silver ores, 119, 120. 
 Antimonite, 
 45% 
 
458 
 
 Antimony, Native, 100. 
 glance, v. Stibnite. 
 
 Apatite, 46, 48, 49, 67, 212. 
 
 Aphanesite, 189. 
 Aphrodite, 307. 
 Aphrosiderite, 319. 
 Aphthitalite, 227. 
 Apjohnite, 198. 
 Aplome, 258. 
 Apophyllite, 294. 
 Aquamarine, 252. 
 Aragonite, 218. 
 Aragotite, 324. 
 Arcanite, 227. 
 Arfvedsonite, 252. 
 Argentine, 121, 216. 
 Argentite, 117, 121. 
 Argillyte, 428. 
 Arkansite, 163. 
 Arkose, 436. 
 Arksutite, 197. 
 Arquerite, 117. 
 Arragonite, 218. 
 Arsenate, Calcium, 214. 
 Cobalt, 167, 168. 
 Copper, 1389. 
 Tron, 185. 
 Lead, 152. 
 Uranium, 170, 171. 
 Zinc, 156. 
 Arsenic, Native, 98. 
 Arsenic group, 98. 
 sulphide, 99. 
 White, 99. 
 Arsenical antimony, 101. 
 cobalt, 165, 166. 
 iron ore, 175, 176. 
 lead ores, 149. 
 nickel, 165, 166. 
 
 Arsenide, Cobalt, 165, 166. 
 
 Copper, 1385. 
 
 Iron, 175, 176. 
 
 Manganese, 188. 
 
 Nickel, 165, 166. 
 Arseniosiderite, 185. 
 Arsenolite, 99. 
 Arsenopyrite, 175. 
 Asbestus, 246, 250. 
 
 Blue, v. Crocidolite. 
 Asbolan, Asbolite, 167. 
 Asmanite, 241. 
 Asparagus-stone, 218. 
 Aspasiolite, 315. 
 
 GENERAL INDEX. 
 
 Asphaltum, 826. 
 Aspidolite, 266. 
 Astrakanite, v. Blédite. 
 Astrophyllite, 266. 
 Atacamite, 1386. 
 Atopite, 214. 
 Auerbachite, 260. 
 Augite, 245. 
 
 andesyte, 450. 
 Augitic trachyte, 448. 
 Aurichalcite, 141, 157. 
 Auriferous pyrite, 173. 
 Auripigmentum, 99. 
 Automolite, 196. 
 | Autunite, 170. 
 Aventurine quartz, 280. 
 
 feldspar, 279. 
 Axinite, 44, 264. 
 Azurite, 141. 
 
 
 
 
 
 
 
 
 
 Babingtonite, 247. 
 
 | Boer v. Allanite. 
 
 Baltimorite, 308. 
 
 Banatite, 447. 
 
 Barite, 220. 
 
 Barium, Compounds of, 220. 
 
 Barytes, 220. 
 
 Barytocalcite, 222. 
 
 Basalt, 451. 
 
 Basanite, 237. 
 
 Bastite, 309. 
 
 Bathvillite, 325. 
 
 Beaumontite, 304. 
 
 Bechilite, 212. 
 
 Benzole, 324. 
 
 Berthierite, 176. 
 
 Beryl, 46, 2682. 
 
 Berzelianite, 135. 
 
 Beyrichite, 165. 
 
 Bieberite, 168. 
 
 Biharite, 312. 
 
 Bindheimite, 152. 
 
 Binnite, 136. 
 
 Biotite, 266. 
 
 Bismite, 1.02. 
 
 Bismuth, 101. 
 
 Bismuth glance, v. Bismuthinite. 
 
 Bismuth ores, 102. 
 carbonate, 102. 
 
 Bismuth nickel, 166. 
 
 Bismuth silver, 116. 
 
 Bismuthinite, 102. 
 
 Bismutite= Bismuth carbonate. 
 
 
 
 
 
Bismutoferrite, 256. 
 Bitter spar, v. Dolomite. 
 Bitumen, 326. 
 
 Elastic, 324. 
 
 Bituminous coal, 327. 
 
 Bituminous shale, 428. 
 
 Black cobalt, 167. 
 copper, 137. 
 jack, 155. 
 lead, 107. 
 silver, 119. 
 
 Blende, 154. 
 
 Blédite, 206, 227. 
 
 Blomstraudite, 170. 
 
 Bloodstone, 287. 
 
 Blue iron earth, 185. 
 copper, 133. 
 vitriol, 137. 
 
 Bodenite, 263. 
 
 Bog iron ore, 181. 
 manganese, 190. 
 
 Bole, Halloysite, 312. 
 
 Boltonite, 256. 
 
 Boracic acid, 97. 
 
 Boracite, 206. 
 
 Borate, Ammonium, 231. 
 Calcium, 212. 
 Hydrogen, 98. 
 Tron, 182. 
 Magnesium, 206. 
 Sodium, 212, 227. 
 
 Borax, 227. 
 
 Bornite, 134. 
 
 Borocalcite, 212. 
 
 Boronatrocalcite, 212. 
 
 Boron group, 97. 
 
 Bort, 108. 
 
 Bosjemanite, 198. 
 
 Botryogen, 182. 
 
 Botryolite, 289. 
 
 Boulangerite, 149. 
 
 Bournonite, 136. 
 
 Boussingaultite, 231. 
 
 Bowenite, 309. 
 
 Bragite, 260. 
 
 Branchite, 324. 
 
 Brandisite, 320. 
 
 Brass, composition of, 144. 
 
 Braunite, 189. 
 Bravaisite, 302. 
 
 Breccia, 426. 
 Bredbergite, 258. 
 Breislakite, v. Pyroxene. 
 
 GENERAL INDEX. 459 
 
 Breithauptite, 166. 
 
 Breunerite = Ferriferous Magne- 
 site. 
 
 Brewsterite, 304. 
 
 Brittle silver ore, 119. 
 
 _| Brochantite, 188. 
 
 Bromargyrite, 121. 
 Bromic silver, 121. 
 Bromlite, 222. 
 Bromyrite, 121. 
 Brongniardite, 120, 149. 
 Bronze, 144. 
 Bronzite, 244. 
 Brookite, 168. 
 Brown coal, 327. 
 hematite, 181. 
 iron ore, 181. 
 ochre, 181. 
 spar, 219. 
 stone, 427. 
 Brucite, 204. 
 Brushite, 214. 
 Bucholzite, 285. 
 Bucklandite, 262. 
 
 4 Bubrstone, 437. 
 
 Buratite, 141, 157. 
 
 Cacholong, 240. 
 Cacoxenite, Cacoxene, 185. 
 Cadmium, Ores of, 159. 
 Cairngorm stone, 235. 
 Caking coal, 327. 
 Calaite, v. Callaite. 
 Calamine, 157, 296. 
 Calaverite, 115. 
 Calcite, 49, 50, 215. 
 Calcium, Compounds of, 207. 
 Calc spar, 215. 
 Caledonite, 149. 
 Callainite, 200. 
 Callais, Callaite, 200. 
 Calomel, 129. 
 Canaanite— White Pyroxene, 245, 
 Cancrinite, 270. 
 Cannel coal, 327, 
 Cantonite, near Covellite, 133. 
 Caoutchouc, Mineral, 324. 
 Capillary pyrites, 164. 
 Carbonaceous shale, 428. 
 Carbonado, 108. 
 Carbonate, Ammonium, 231. 
 
 Barium, 221. 
 
 Calcium, 215, 218, 219. 
 
460 GENERAL INDEX. 
 
 Carbonate, Bismuth, 102. 
 Cerium, 203. 
 Copper, 140, 141. 
 Tron, 185. 
 Lanthanum, 208. 
 Lead, 152. 
 Magnesium, 207, 219. 
 Manganese, 191. 
 Sodium, 229, 280. 
 Strontium, 228. 
 Uranium, 171. 
 Yttrium, 203. 
 Zinc, 156. 
 
 Carbonic acid, 108, 423. 
 
 Carburetted hydrogen, 821. 
 
 Carnallite, 205. 
 
 Carnelian, 236. 
 
 Carpholite, 296. 
 
 Carrara marble, 483. 
 
 Cassiterite, 160. 
 
 Castor, Castorite, 249. 
 
 Catapleiite, 295. 
 
 Cataspilite, 312. 
 
 Catlinite, 429. 
 
 Cat’s-eye, 236. 
 
 Celadonite, 307. 
 
 Celestite, Celestine, 222. 
 
 Cerargyrite, 120, 121. 
 
 Cerite, 296. 
 
 Cerium ores, 201. 
 
 Cerolite, 309. 
 
 Cerussite, 152. 
 
 Cervantite, 101. 
 
 Chabazite, 800. 
 
 Chaleanthite, 137. 
 
 Chalcedony, 285. 
 
 Chalcocite, 182. 
 
 Chalcodite, 307. 
 
 Chalcolite, 170. 
 
 Chalcomorphite, 296. 
 
 Chalcophanite, 189. 
 
 Chalcophyliite, 139. 
 
 Chalcopyrite, 133. 
 
 Chalcosiderite, 185. 
 
 Chalcosine, 182. 
 
 Chalcostibite, 136. 
 
 Chalcotrichite=Capillary Cuprite, 
 
 136. 
 Chalk, 215, 482. 
 Chalybite=Siderite. 
 Chathamite, 0. Chloanthite. 
 Chert, 237, 436. 
 Chessy Copper, v. Azurite, 
 
 Chesterlite, v. Microcline. 
 Chiastolite, 285. 
 Childrenite, 200. 
 Chiolite, 197. 
 Chloanthite, 165. 
 Chlor-apatite, 213. 
 Chlorastrolite, 296. 
 Chloride, Ammonium, 280. 
 
 Copper, 136. 
 
 Lead, 149, 153. 
 
 Magnesium, 205. 
 
 Mercury, 129. 
 
 Potassium, 224. 
 
 Silver, 120. 
 
 Sodium, 224. 
 Chlorite argillyte, 454. 
 
 Group, s 
 
 schist, 453. 
 Chloritoid, 320. 
 Chlormagnesite, 205. 
 Chloropal, 307. 
 Chloropheite, 318. 
 Chlorophane, 208. 
 Chlorophyllite, 265, 215. 
 Chlorotile, 1389. 
 Chodneffite, 197. 
 Chondrodite, 281. 
 Chonicrite, 317. 
 Chromate, Lead, 150, 151. 
 Chrome yellow, 151. 
 Chromic iron, 180. 
 Chromite, 180. 
 Chrysoberyl, 196. 
 Chrysocolla, 142, 295. 
 Chrysolite, 205. 
 
 rock, 453. 
 Chrysolyte, 453. 
 
 | Chrysoprase, 236. 
 
 Chrysotile, 308. 
 Churchite, 203. 
 Cimolite, 307. 
 Cinnabar, 128. 
 Cinnamon stone, 257. 
 Cipolin marble, 434. 
 Citrine, 235. 
 Claudetite, 100. 
 Clausthalite, 149. 
 Clay, 429. 
 
 iron-stone, 177, 181, 186. 
 
 slate, 428. 
 Cleavelandite, 278. 
 Cleiophane, 155. 
 Cleveite, 170. 
 
GENERAL INDEX. 
 
 Clingmanite, 319. 
 Clinkstone, 444. 
 Clinochlore, 319. 
 Clinoclasite, 139. 
 Clinohumite, 281. 
 Clintonite, v. Seybertite. 
 Coal, Mineral, 327. 
 Brown, 828. 
 Cannel, 327. 
 Cobalt bloom, 167. 
 glance, 165. 
 Ores of, 163. 
 pyrites, 164. 
 vitriol, 168. 
 Cobaltite, Cobaltine, 165. 
 Coccolite, 246. 
 Coke, 828. 
 Collyrite, 296. 
 Colophonite, 258. 
 Coloradoite, 129. 
 Colorados, 121. 
 Columbates, 170, 1838, 202, 208, 
 214. 
 Columbite, 183. 
 Columbiu 1 184, 
 Comptonite, 298. 
 Conglomerate, 426. 
 Connellite, 47 (f. 11), 188. 
 Cookeite, 314. 
 Copal, Fossil. 
 Copaline, Copalite, 320. 
 Copiapite, 182. 
 Copper, Native, 131. 
 froth, 1389. 
 glance, 182. 
 Gray, 185. 
 mica, 180. 
 nickel, 166. 
 Ores of, 180. 
 pyrites, 133, 184. 
 vitriol, 137. 
 Copperas, 182. 
 Coprolites, 213. 
 Coquimbite, 182. 
 Cordierite, 264. 
 Corneous lead, 158. 
 Cornwallite, 139. 
 Corsyte, 448. 
 Corundellite, 319. 
 Corundophilite, 319. 
 Corundum, 192. 
 Cossaite, 314. 
 Cotunnite, 149. 
 
 | Covellite, Covelline, 133. 
 Crednerite=Cu;Mn,Og. 
 Crichtonite, 0. Menaccanite. 
 Crocidolite, 252. 
 
 Crocoite, Crocoisite, 150. 
 Cronstedtite, 319. 
 
 1 Crookesite, 185. 
 _|Cryolite, 197. 
 
 Cryophyliite, 268. 
 Cryptolite, 203. 
 Cryptomorphite, 212. 
 Cubanite, 184. 
 
 Cube ore, 185. 
 
 Cubic nitre, 229. 
 Culsageeite, 317. 
 Cummingtonite, 250. 
 Cuprite, 186. 
 Cuproscheelite, 212. 
 Cuprotungstite, 188. 
 Cyanite, 286. 
 Cyanotrichite, 138. 
 Cymatolite, 293. 
 Cyprine, 261. 
 
 Daleminzite, 118. 
 Damourite, 313. 
 
 slate, 441. 
 Danaite, 175. 
 Danalite, 256. 
 Danburite, 264. 
 Datholite, Datolite, 289. 
 Daubreelite, 180. 
 Daubreite,=Bismuth oxichloride. 
 Dawsonite, 201. 
 Dechenite=Lead vanadate. 
 Degeroite, 315. 
 Delessite, 318. 
 Delvauxite, v. Dufrenite. 
 Derbyshire spar, 209. 
 Descloizite, 
 Desmine, 303. 
 Deweylite, 309. 
 Diabantachronyn, 318. 
 Diabantite, 318. 
 Diabase, 452. 
 Diallage, Green, 246. 
 Diallogite, v. Rhodochrosite. 
 Diamond, 103. 
 Dianite, v. Columbite. 
 Diaphorite = Trimetric Freiesleb- 
 
 enite. 
 Diaspore, 194. 
 Dichroite, 264. 
 
462 GENERAL INDEX. 
 
 Dickinsonite, 191. 
 Didymium ores, 201, 203. 
 Dibydrite, 139. 
 Dinite, 324. 
 Diopside, 246. 
 Dioptase, 141, 256, 295. 
 Dioryte, 446. 
 Diphanite, 319. 
 Dipyre, 269. 
 Disterrite, 320. 
 Disthene, 286. 
 Ditroyte, 444. 
 Dog-tooth Spar, 215. 
 Dolerophanite, 188. 
 Doleryte, 451. 
 pitchstone, 452. 
 Dolomite, 207, 219. 
 Dolomyte, 482, 484, 
 Domeykite, 135. 
 Domyte, 448. 
 Dreelite, 221. 
 Dry-bone, 158, 364. 
 Dudleyite, 320. 
 Dufrenite, 185. 
 Dufrenoysite, 149. 
 Dunyte, 453. 
 Durangite, 199. 
 Dutch white, 221. 
 Dysanalyte, 202, 214. 
 Dyscrasite, 119. 
 Dysluite, 196. 
 Dysodile, 825. 
 Dysyntribite, 312. 
 
 Earthy cobalt, 167. 
 Ecdemite, 152. 
 Eclogyte, 453. 
 Edelforsite, 245. 
 Edenite, 251. 
 Fdingtonite, 296. 
 Edwardsite, v. Monazite. 
 Ehlite, 139. 
 Ekebergite, 269. 
 Ekmannite, 316. 
 Eleolite, 269. 
 Elaterite, 324. 
 Electro-silicon, 480. 
 Electrum, 110. 
 Eliasite, 170. 
 ‘Embolite, 121. 
 Embrithite, v. Boulangerite. 
 Emerald, 252. 
 
 Oriental, 193. 
 
 Emerald, nickel, 168. 
 Emery, 193. 
 
 Emerylite, 319. 
 Emplectite, 136. 
 
 Enargite, 136. 
 
 Enceladite, 0. Warwickite. 
 Enstatite, 244. 
 
 Enysite, 138. 
 
 Eosite, near Vanadinite. 
 Eosphorite, 200. 
 Epichlorite, 316. 
 Epidosyte, 453. 
 
 Epidote, 262. 
 
 i Kpistilbite, 802, 304. 
 Epsom salt, Epsomite, 205. 
 Erbium ores, 201. 
 Erdmannite, 296. 
 
 Erinite, 1389. 
 Erubescite, 134. 
 Erythrite, 167. 
 Esmarkite, 265, 315. 
 Eucairite, 118, 185. 
 Euchroite, 189. 
 Euclase, 288. 
 
 Eucolite, 254. 
 Eucrasite, 296. 
 Eucryte, 452. 
 Eudyalite, Kudialyte, 254, 260. 
 Eudnophite, 300. 
 Eukairite, v. Eucairite. 
 Eulysyte, 453. 
 Eulytite, Eulytine, 102, 256. 
 Euosmite, 325. 
 Euphotide, 449. 
 Euphyliite, 314. 
 Eupyrchroite, 213. 
 Euralite, 318. 
 
 Euryte, 442. 
 
 Euxenite, 202. 
 
 Fahlerz, 135. 
 Fahlunite, 265, 314. 
 Fairfieldite, 191. 
 Fassaite, 246. 
 Faujasite, 300. 
 Fayalite, 256. 
 Feather ore, v. Jamesonite. 
 Feldspar Group, 272. 
 Felsite, 280. 
 
 Felspar, v. Feldspar. 
 Felsyte, 442. 
 Fergusonite, 202, 260. 
 Fibroferrite, 182, 
 
GENERAL INDEX. 
 
 Fibrolite, 285. 
 
 Fichtelite, 324. 
 
 Fiorite, 240. 
 
 Fioryte, 437. 
 
 Fireblende v. Pyrostilpnite. 
 
 Fire-marble, 4381. 
 
 Fire-opal, 239. 
 
 Fischerite, 200. 
 
 Flint, 237. 
 
 Float-stone, 241. 
 
 Flos ferri, 218. 
 
 Fluellite, 197. 
 
 Fluidal texture, 418. 
 
 Fluocerine, 202. 
 
 Fluocerite, 202. 
 
 Fluor-apatite, 2138. 
 
 Fluor, Fluorite, 208. 
 
 Fluor spar, 208. 
 
 Fluorides, Aluminum, 197, 
 
 Calcium, 208. 
 
 Foliated tellurium, 149. 
 
 Fontainebleau limestone, 216. 
 
 Foresite, 304. 
 
 Forsterite, 256. 
 
 Fowlerite, 247. 
 
 Foyayte, 446. 
 
 Franklinite, 158, 179, 456. 
 
 Free-stone, 427. 
 
 Freibergite=Argentiferous Tetra- 
 hedrite. 
 
 Freieslebenite, 120, 121, 149. 
 
 Frenzelite, 102. 
 
 Friedelite, 256. 
 
 Gabbro, 449, 450, 454. 
 Gadolin, Gadolinite, 203, 263. 
 Gagates, 828. 
 Gahnite, 196. 
 Galena, Galenite, 121, 145. 
 Galmei, 157. 
 Ganomalite, 158. 
 Garnet, 256. 
 
 rock, 452. 
 Garnetyte, 452. 
 Garnierite, 168. 
 Gastaldite, 252. 
 Gay-Lussite, 230. 
 Gearksutite, 197. 
 Gehlenite, 284. 
 Genthite, 168, 309. 
 Geocerite, 325. 
 Geocronite, 149. 
 Geomyricite, 325. 
 
 463 
 
 Gersdorffite, 166. 
 Geyserite, 240, 437. 
 Gibbsite, 194. 
 Gieseckite, 270, 312. 
 Gigantolite, 265 815. 
 Gillingite, 316. 
 Girasol, 239. 
 Gismondite, Gismondine, 296. 
 Glagerite, 312. 
 Glaserite, ». Arcanitc. 
 Glass, 416. 
 Glauber salt, 41, 68, 226. 
 Glauberite, 227. 
 Glaucodot=Cobaltic Arsenopyrite, 
 Glaucolite, 269. 
 Glauconite, 307, 429. 
 Glaucophane, 252, 446. 
 Globulites, 416. 
 Gmelinite, 301. 
 Gneiss, 439. 
 Gold, 109. 
 Goslarite, 156. 
 Géothite, 182. 
 Grahamite, 326. 
 Gramenite, 307. 
 Grammatite, 249. 
 Granite, 487. 
 Granitone, 449, 450. 
 Granular quartz, 435. 
 Granulyte, 439. 
 Graphic granite, 438, 439. 
 
 tellurium, 118 
 Graphite, 107. 
 Grastite, 319. 
 Gray antimony, 2. Stibnite, 
 
 copper, 135. 
 Green earth, 307. 
 
 sand, 429. 
 Greenockite, 159. 
 Greenovite, 290. 
 Greenstone, 446, 448. 
 Greisen, 441. 
 Grindstones, 427. 
 Grit, 426. 
 Grochauite, 319. 
 Groppite, 314. 
 Grossularite, 257. 
 Griinauite, 166. 
 Guadalcazarite, 129. 
 Guanajuatite, 102. 
 Guano, 213. 
 Guarinite, 291. 
 Gumumite, 170. 
 
464. GENERAL INDEX. 
 
 Gurhofite, 219. 
 Guyaquillite, 325. 
 Gymnite, 309. 
 Gypsum, 56, 210. 
 Gyrolite, 293. 
 
 Haidingerite, 214. 
 Hair-salt, 205. 
 
 Halite, 224. 
 
 Hallite, 318. 
 Halloysite, 312. 
 Halotrichite, 182, 198. 
 Hamburg white, 221. 
 Harmotome, 301. 
 Harrisite, 183. 
 
 Hartite, 324. 
 Hatchettite, Hatchettine, 824. 
 Hatchettolite, 170, 214. 
 Hauerite, 188. 
 Haureaulite, 191. 
 Hausmannite, 189. 
 Hatiyne, Haiiynite, 270. 
 Hauynophyre, 482. 
 Haydenite, 301. 
 Hayesine, 212. 
 
 Heavy spar, 220. 
 Hebronite, 199. 
 Hedenbergite, 246. 
 Hedyphane, 152. 
 Heliotrope, 237. 
 Helminthe, 319. 
 Helvite, Helvin, 256, 
 Hematite, 176, 455. 
 
 Brown, 181. 
 
 Red, 176. 
 Henwoodite, 200. 
 Hercynite, 196. 
 Herderite, 199. 
 Herschelite, 301. 
 Hessite, 118. 
 Heterolite, 189. 
 Heterosite, 191. 
 Heulandite, 303. 
 Hisingerite, 315. 
 Heoernesite, 207. 
 Homilite, 289. 
 Honey-stone, 201. 
 
 - Hopeite, 158. 
 Hornblende, 249, 251, 
 
 schist, 446. 
 
 Horn quicksilver, 129. 
 
 silver, 120. 
 Hornstone, 2387, 
 
 Horse-flesh ore, v. Bornite. 
 Hortonolite, 256. 
 Houghite, 194. 
 
 Howlite, 212. 
 Huascolite, 155. 
 Hiibnerite, 183. 
 Hudsonite, 246. 
 Humboldtilite, 261. 
 Humboldtite, 289. 
 Humite, 281. 
 Hureaulite, 191. 
 Hyacinth, 259, 260, 284. 
 Hyalite, 240. 
 Hyalomelan, 452. 
 Hyalophane, 276. 
 Hyalosiderite, 255. 
 Hyalotecite, 153. 
 Hydrargillite, 194. 
 Hydraulic limestone, 217, 481, 
 Hydroboracite, 212. 
 Hydrocarbons, 320. 
 Hydrocerussite, 153. 
 Hydrochloric acid, 238L 
 Hydrocyanite, 188. 
 Hydrodolomite, 220. 
 Hydrogen, 231. 
 Hydromagnesite, 204, 207. 
 Hydro-mica Group, 312. 
 Hydromica schist, 440. 
 Hydrophane, 240. 
 Hydrophite, 309. 
 Hydrotalcite, 194. 
 Hydrozincite, 157. 
 Hypersthene, 244. 
 Hypersthenyte, 450, 451. 
 Hyperyte, 450. 
 
 Iberite, 315. 
 Ice, crystallization of, 4, 
 Iceland spar, 215. 
 Idocrase, 261. 
 Idrialine, Idrialite, 324. 
 Thleite, 182. 
 Ilmenite, 178. — 
 Ilvaite, 2638. 
 Inclusions, 428. 
 Indianite, 275. 
 Indicolite, 2838. 
 Infusorial earth, 241. 
 Iodargyrite, 121. 
 Iodide, Mercury, 129, 
 Silver, 121. 
 Iodyrite, 121, 
 
GENERAL INDEX. 
 
 Tolite, 264. 
 Hydrous, 315. 
 Tonite, 325. 
 Tridosmine, 127. 
 Iron, 171. 
 Iron, Ores of, 171, 455. 
 Magnetic, 178, 455. 
 -pyrites, 172. 
 sinter, 185. 
 Ironstone, Clay, 177, 181. 
 Isenite, 448. 
 Iserine, v. Menaccanite. 
 Isoclasite, 189. 
 Itabyrite, 440, 455. 
 Itacolumyte, 104, 486. 
 Ittnerite, 270. 
 Ixolyte, 824. 
 
 Jade, 250. - 
 Jadeite, 268. 
 Jamesonite, 149. 
 Jargon, 260. 
 Jarosite, 182. 
 Jasper, 237. 
 rock, 437 
 Jaspery clay 1ron-stone, 177. 
 Jefferisite, 317. 
 Jeffersonite, 246. 
 Jelletite, 258. 
 Jenkinsite, 309. 
 Jenzschite, 241. 
 Jet, 328. 
 Johannite, 171. 
 Jollyte, 316. 
 Joseite, 102. 
 
 Kalinite, 198. ; 
 Kimmererite, 318. 
 Kaneite, 188. 
 
 _ Kaolin, Kaolinite, 280, 310. 
 Karyinite, 152. 
 Keilhauite, 2038, 291, 
 Kermesite, 101. . 
 Kerrite, 318. ° @ 
 Kersanton, 444. 
 Kersantyte, 448. 
 Kerstenite, 150. 
 Kieserite, 205. 
 Kinzigyte, 444. 
 Kjerulfine, 207. 
 Knebelite, 256. 
 Kobellite, 149. 
 Kochelite, 202. 
 
 Kongsbergite, 117. 
 Konigite, Kénigine, 188. 
 Konlite, 324. 
 
 Kottigite, 156, 167. 
 Kotschubeite, 319. 
 
 Kreittonite, 196. 
 
 Krennerite, 116. 
 Krisuvigite, 138. 
 Kronkite, 188. 
 Kupfferite, 252. 
 Kyanite, 286. 
 
 Labradioryte, 448. 
 Labrador feldspar, 276. 
 Labradorite, 276. 
 Labradorite-dioryte, 448. 
 Lagonite, 182. 
 Lampadite, 190. 
 Lanarkite, 151. 
 Langite, 138. 
 Lanthanite, 2038. 
 Lanthanum ores, 201. 
 Lapis-lazuli, 270. 
 Lapis ollaris, 304. 
 Larderellite, 231. 
 Latrobite, ». Anorthite. 
 
 Laumontite, Laumonite, 298. 
 
 Laurite, 127. 
 Lazulite, 199. 
 Lead, ores of, 145 
 Leadhillite, 151. 
 Lecontite, 231. 
 Lederite, 291. 
 Lebrbachite, 149. 
 Lenzinite, 312. 
 Leopoldite, v. Sylvite. 
 Lepidokrokite, 182. 
 Lepidolite, 268. 
 Lepidomelane, 266. 
 Leptinyte, 439. 
 
 Lettsomite, ». Cyanotrichite. 
 
 Leuchtenbergite, 319. 
 Leucite, 271 
 Leucitophyre, 452. 
 Leucityte, 443. 
 Leucophanite, 256. 
 Leucopyrite, 176. 
 Levyne, Levynite, 301. 
 Lherzolyte, 453. 
 Libethenite, 189. 
 Liebigite, 171. 
 Lievrite, v. Ilvaite. 
 Lignite, 828. 
 
 30 
 
 465 
 
466 
 
 Lillite, 316. 
 
 Limbachite, 309. 
 Limburgyte, 453. 
 Lime-titanate, v. Perofskite. 
 Limestone, 216, 480, 482. 
 Limnite, 182. 
 
 Limonite, 181. 
 
 Linarite, 138. 
 Lindackerite, 168. 
 Linnezite, 164. 
 Liroconite, 139. 
 Lithiophilite, 190. 
 Lithium phosphates, 190, 199. 
 Lithographic stone, 217. 
 Lithomarge, 312. 
 
 Liver ore, 129. 
 Livingstonite, 101. 
 Lodestone, 141, 179. 
 Leess, 429. 
 
 Loganite, 318. 
 Léllingite, 176. 
 Lophoite, 319. 
 
 Loéweite, 227, 206. 
 Loéwigite, 199. 
 Loxoclase, 278. 
 Ludlamite, 185. 
 Ludwigite, 206. 
 Lumachelle, 431. 
 Liineburgite, 207. 
 Lydian stone, 237. 
 Lyncurium, 284. 
 
 Macle, 285. 
 
 Maconite, 318. 
 
 Magnesite, 207. 
 
 Magnesium, Compounds of, 204. 
 
 Magnetic iron ore, 178, 455. 
 pyrites, 174. 
 
 Macgnetite, 59, 178, 423. 
 
 Maenoferrite, 204. 
 
 Magnolite, 129. 
 
 Malachite, Blue, 141. 
 Green, 140, 200. 
 
 Malacolite, 246. 
 
 Malacon, 260. 
 
 Maldonite, 110. 
 
 Malinowskite, 136. 
 
 Manganblende, 188. 
 
 Manganepidot, v. Epidote. 
 
 Manganese ores, 188. 
 spar, 247. 
 
 Manganite, 189. 
 
 Marble, 216, 481, 482. 
 
 GENERAL INDEX. 
 
 Marble, Verd-antique, 454. 
 
 Marcasite, 174. 
 
 Margarite, 319. 
 
 Margarodite, 313. ; 
 
 Margarophyllite Section, 304. 
 
 Marialite, 269. 
 
 Marl, 482. 
 
 Marmatite, ». Sphalerite. 
 
 Marmolite, 308. 
 
 Marsh gas, 321. 
 
 Martite, 177. 
 
 Mascagnite, Mascagnine, 281. 
 
 Masonite, 320. 
 
 Matlockite=Lead oxichloride. 
 
 Medjidite, 171. 
 
 Meerschaum, 306. 
 
 Meionite, 269. 
 
 Melaconite, 137. 
 
 Melanite, 258. 
 
 Melanochroite, 151. 
 
 Melanolite, 315. 
 
 Melanophlogite, 241. 
 
 Melanterite, 182. 
 
 Melaphyre, 450. 
 
 Melilite, Mellilite, 261. 
 
 Melinophane, 256. 
 
 Meliphanite, 256. 
 
 Mellite, 201. 
 
 Menaccanite, 178. 
 
 Mendipite, 149. 
 
 Mendozite, 198. 
 
 Meneghinite, 149. 
 
 Menilite, 240. 
 
 Mercury, Ores of, 128. 
 Native, 128. 
 
 Mesitine, Mesitite, 186. 
 
 Mesolite, 299. 
 Mesotype v. Natrolite. 
 Metabrushite, 214. 
 Metachlorite, 319. 
 Metacinnabarite, 129. 
 Metadoleryte, 452. 
 Metaxite, 308. 
 Metaxoite, 317. 
 Miargyrite, 120. 
 Miarolyte, 488. 
 Miascyte, 444. 
 Mica, 265. 
 Mica-argillyte, 441, 
 dioryte, 444. 
 phyllyte, 441. 
 schist, 440. 
 Michaelsonite, 268. 
 
GENERAL INDEX. 467 
 
 Natrolite, 299. 
 
 Natron, 229. 
 
 Naumannite, 118. 
 
 Needle ore, v. Aikinite. 
 Neft-gil, 324. 
 
 Nemalite, 204 
 
 Neotocite, 316. 
 Nepheline-doleryte, 452. 
 Nephelinyte, 452. 
 Nephelite, Nepheline, 269. 
 
 Microcline, 278. 
 
 Microlite, 202, 214. 
 Microlites, 416, fig. 6. 
 Microsommite, 270. 
 Middletonite, 325. 
 
 Milarite, 252. 
 
 Millerite, 164. 
 
 Millstone grit, 426. 
 Mimetene, Mimetite, 46, 152. 
 Mineral coal, 327. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 oil, 321. Nephrite, 250. 
 pitch, 326. Newjanskite, 127. 
 Minette, 441. Niccolite, 166. 
 Minium, 149. Nickel glance, v. Gersdorflite. 
 
 Mirabilite, 41, 226. 
 Misenite, 227. 
 Mispickel, 175. © 
 Mizzonite, 269. 
 Mocha stone, 2386. 
 Molybdate, Lead, 151. 
 Molybdenite, 96. 
 Molybdite, 97. 
 
 Nickel-gymunite, 309. 
 Nickel, Ores of, 164. 
 stibine, 166. 
 Nigrine, 162. 
 Niobite, 0. Columbite. 
 Niobium, Compounds of, 184. 
 Nitrate, Calcium, 214. 
 Potassium, 228. 
 
 Monazite, 41, 203. Sodium, 229. 
 Monimolite, 152. _| Nitratine, 229. 
 Monradite, 295. Nitre, 228. 
 
 -Montanite, 102. 
 Monticellite, 256. 
 Montmartite, v. Gypsum. 
 Montmorillonite, 307. 
 Montronite, 307. 
 Moonstone, 277, 279. 
 Mordenite, 304. 
 Morenosite, 168. 
 Mosandrite, 263. 
 Moss agate, 236. 
 Mottramite, 139. 
 Mountain cork, 250. 
 leather, 250. 
 tallow, 324. 
 Muller’s glass, 240. 
 Mundie, 174. 
 Muntz metal, 144. 
 Muriatic acid, 231. 
 Muromontite, 263. 
 Muscovite, 267. 
 Muscovy glass, 268. 
 Miisenite, v. Siegenite. 
 
 Nitrocalcite, 214. 
 Vitromagnesite, 206. 
 Nohlite, 202. 
 
 Noryte, 450. 
 
 Nosean, Nosite, 270. 
 oumeite, 168. 
 Yovaculyte, 486, 453. 
 Nuttalite, 269. 
 
 A IA'A 
 
 
 
 AAA, 
 
 Ochre, Red, 167, 176. 
 Yellow, 181. 
 Octahedrite, 163. 
 (EHllacherite, 314. 
 Cirstedite, 260. 
 Ogcoite, 319. 
 Okenite, 293. 
 Oligoclase, 44, 276. 
 Olivenite, 139. 
 Olivine, 255. 
 Onyx, 236. 
 Odlite, 216. 
 Opal, 239. 
 Opal, Jasper, 240. 
 Ophiolite, 308. 
 Ophiolyte, 454. 
 Ophite, 447. 
 Orangite, 296. 
 Orpiment, 99. 
 
 Nadorite, 152. 
 Nagyagite, 116, 149. 
 Naphtha, 321. 
 Naphthaline, 324. 
 Natroborocalcite, 212. 
 
468 GENERAL INDEX. 
 
 Orthite, 263. Phacolite, 301. 
 Orthoclase, 44, 278. Pharmacolite, 214. 
 Osteolite, 2138. Pharmacosiderite, 185. 
 Ottrelite, 320. Phenacite, 254. 
 Ouvarovite, 258. Phillipite, 138. 
 Oxide, Cobalt, 167. Phillipsite, 302. 
 
 Iron, 176. Phlogopite, 68, 266. 
 
 Lead, 149. Pheenicochroite, 151. 
 
 Magnesium, 204. Pholerite, 312. 
 
 Manganese, 188. Phonolyte, 444. 
 
 Tin, 160. Phosgenite, 153. 
 
 Uranium, 169. Phosphate, Aluminum, 199, 200. 
 
 Zinc, 155. Ammonium, 281. 
 Ozarkite, 298. Calcium, 212, 214. 
 Ozocerite, Ozokerite, 324. Cerium, 208. 
 
 Copper, 1389. 
 
 Pachnolite, 197. Tron, 184, 185, 191. 
 Pacos, 121. Lead, 151. 
 Pagodite, 312. Manganese, 190, 191. 
 Palagonite, 312. Uranium, 170. 
 Palladium, 127. Yttrium, 203. 
 Paraffin, 324. Phosphochalcite, 139. 
 Paragonite, 314. Phosphorite,213. 
 
 schist, 441. Phrenite, 295. 
 Paranthine, 269. Phylilite, 320. 
 Parasite, v. Boracite. Phyllyte, 428. 
 Pargasite, 251: Physalite, 287. 
 Parisite, 203. Pickeringite, 198. 
 Parophite, 314. Picotite, 195. 
 Parophite schist, 441. Picrolite, 308. 
 Pattersonite, 319. Picromerite, 205, 227, 
 Pealite, ». Geyserite. Picrophyll, 295. 
 Pearl sinter, 437. Picrosmine, 295. 
 
 spar, 219. Picryte, 453. 
 
 stone, 443. Piedmontite, 262. 
 Pectolite, 293. Pilinite, 304. 
 Peganite, 200. Pimelite, 168. 
 Pegmatolite, v. Orthoclase. Pinguite, 307. 
 Pegmatyte, 438, 439. Pinite, 312. 
 Pelagite, 189. Pinitoid, 312. 
 Pelhamite, 318. Pipe-clay, 427. 
 Pencil-stone, 306. Pipestone, 429. 
 Pennine, Penninite, 318. Pisanite, 182. 
 Pennite, 220. Pisolite, 216. 
 Peperino, 429. Pistacite, 262. 
 Periclase, Periclasite, 204. Pitchblende, 169. 
 Peridot, ». Chrysolite. Pitkarandite, 295. 
 Peridotyte, 451. Pitticite, v. Iron Sinter. 
 Perofskite, Perowskit, 163. Plagioclase, 275, 425. 
 Petalite, 248. Plagionite, 149. 
 Petroleum, 321. Plasma, 237. 
 Petrosilex, 442. Plaster of Paris, 211. 
 
 Petzite, 116, 118. Platinum, Native, 124. 
 
GENERAL INDEX. 469 
 
 Platiniridium, 127. Pyrargyrite, 119, 121. 
 Pleonaste, v. Spinel. Pyreneite, 258. 
 Plumbago, 107. Pyrite, 5, 6, 172. 
 Plumbic ochre, 149. Pyrites, Arsenical, 175. 
 Plumbogummite, 149. Auriferous, 173. 
 Plumose mica, 267. Capillary, 164. 
 Polianite, v. Pyrolusite. Cobalt, 164. 
 Polishing powder, 480. Cockscomb, 174, 
 Pollucite, Pollux, 254. Copper, 183. 
 Polyargite, 312. Hepatic, 174. 
 Polyargyrite, 120. Iron, 172. 
 Polybasite, 120, 186. Magnetic, 174. 
 Polycrase, 202. Radiated, 174. 
 Polyhalite, 205, 227. Spear, 174. 
 Polylite, 246. Variegated, 134, 
 Polymignite, 202, 260. White iron, 174. 
 Porcelain jasper, 442. Pyrochlore, 202, 214. 
 Porcelanyte, 442. Pyrochroite, 189. 
 Porcellophite, 308. Pyrolusite, 188. 
 Porfido verde antico, 452. Pyromorphite, 151. 
 Porpezite, 127. Pyrope, 258. 
 Porphyrite, 447. Pyrophosphorite, 214. 
 Porphyritic structure, 415. Pyrophyllite, 306. 
 Porphyry, 417, 442, 448. slate, 455. 
 Antique green, 452. Pyrophyllyte, 455, 
 Antique red, 415, 447. Pyrophysalite, 287. 
 Porphyryte, 447. Pyrosclerite, 317. 
 Portor, 431. Pyrosmalite, 296. 
 Potassium, Compounds of, 223. Pyrostilpnite, 120. 
 Potstone, 304. Pyroxene, 245. 
 Potter’s clay, 429. Pyroxenyte, 452. 
 Pozzuolana, 428. Pyrrhopeecilon, 445. 
 Prase, 235. Pyrrhosiderite, 182. 
 Pregattite, 314. Pyrrhotite, 174. 
 Prehnite, 295. 
 Priceite, 212. Quartz, 58, 54, 58, 283, 238, 435. 
 Prochlorite, 54, 319. andesyte, 447. 
 Propylyte, 447. dioryte, 446. 
 Protogine, 440. felsyte, 442. 
 Protovermiculite, 318. propylyte, 447. 
 Proustite, 119, 121. syenyte, 445. 
 Przibramite, 159. trachyte, 442. 
 Psammite, v. Sandstone. Quartzyte, 435. 
 Pseudomalachite, 139. Quick lime, 217. 
 Pseudophite, 318. Quicksilver. See Mercury. 
 Pseudotriplite, 191. 
 Psilomelane, 189. Raimondite, 182. 
 Psittacinite, 139. Realgar, 99. 
 Pudding-stone, 426. Red antimony, 101. 
 Purple copper, v. Bornite. chalk, 177. 
 Pycnite, 287. copper ore, 136. 
 Pyrallolite, 295. hematite, 176. 
 
 Pyrargillite, 315. lead, 149, 
 
470 
 
 Red ochre, 167, 176. 
 silver ore, 119. 
 zinc ore, 155. 
 
 Reddingite, 191. 
 
 Redruthite, 132. 
 
 Refdanskite, 308. 
 
 Remingtonite, 168. 
 
 Rensselaerite, 805, 454. 
 
 Retinalite, 308. 
 
 Rhabdophane, 203. 
 
 Rheetizite, 286. 
 
 Rhodium gold, 110. 
 
 Rhodizite, 206. 
 
 Rhodochrome, 818. 
 
 Rhodochrosite, 191. 
 
 Rhodonite, 191, 247. 
 
 Rhodophyllite, 318. 
 
 Rhomb-spar, 219. 
 
 Rhyolyte, 418, fig. 8. 
 
 Ripidolite, 318. 
 
 Rittingerite, near Freieslebenite. 
 
 Rivotite, 139. 
 Rock cork, v. Hornblende. 
 
 crystal, 234. 
 
 meal, 216. 
 
 milk, 216. 
 
 salt, 224. 
 Reepperite, 256. 
 Reesslerite, 207. 
 Rogersite, 203. 
 Romeine, Romeite, 214. 
 Roscoelite, 314. 
 Roselite, 168. 
 Rosite, 312. 
 Rosso antico, 415, 447. 
 Rothoffite, 258. ; 
 Rottisite, 168, 310. 
 Rubellite, 283. 
 Ruby, Spinel, 198. 
 
 Ruby-blende, v. Pyrargyrite, 
 
 Ruby silver, 119. 
 
 Ruin marble, 431. 
 Ruthenium, Ores of, 127. 
 Rutherfordite, 203. 
 Rutile, 57, 162. 
 
 Safflorite, 165. 
 
 Sahlite, 246. 
 
 Sal ammoniac, 280. 
 Salmiak, 280. 
 
 Salt, Common, 29, 224. 
 Samarskite, 170, 202. 
 Sandstone, 426. 
 
 GENERAL INDEX. 
 
 Sanidin, 278. 
 
 Saponite, 310. 
 
 Sapphire, 198. 
 Sarcolite, 269. 
 
 Sard, 236. 
 
 Sardonyx, 236. 
 Sartorite, 149. 
 
 Sassolite, Sassolin, 97. 
 Satin-spar, 210, 215. 
 Saussurite, 263, 410, 449. 
 Saussurite group, 410. 
 Savite, o. Natrolite. 
 Scapolite, 268. 
 Scarbroite, 296. 
 Sceleretinite, 325 
 Scheelite, 212. 
 Schiller-spar, 309. 
 Schorl (pron. Shor), 283. 
 Schorlomite, 292. 
 Schreibersite, 175. 
 Schriétterite, 296. 
 Scolecite, Scolezite, 299. 
 Scorodite, 185. 
 Scotiolite, 315. 
 
 Selenate, Copper, 1385. 
 
 Lead, 150. 
 Selenide, Lead, 149. 
 
 Mercury, 149. 
 
 Silver, 118. 
 Selenite, 210. 
 Selenpalladite, 127. 
 
 ‘| Semiopal, 240. 
 Senarmontite, 101. 
 Sepiolite, 306. 
 Sericite, 314. 
 
 slate, 441. - 
 Serpentine, 307, 454. 
 Severite, 312. 
 Seybertite, 320. 
 
 Shale, 427. 
 
 Siderite, 185. 
 
 Siegenite, 164. 
 
 Silaonite, 102. 
 
 Silex, v. Quartz. 
 
 Silica, 233. 
 
 Silicate, Copper, 141, 142. 
 
 Lead, 153. 
 
 Nickel, 168. 
 
 Zine, 157. 
 Silicates, 242. 
 Siliceous sinter, 240, 487. 
 
 slate, 486. 
 Silicified wood, 288. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
GENERAL INDEX. 471 
 
 Silicoborocalcite, 212. 
 
 Sillimanite, 285. 
 
 Silt, 429. 
 
 Silver, 116, 121. 
 Compounds of, 216. 
 glance, 117. 
 
 Sinter, Siliceous, 240. 
 
 Sipylite, 202. 
 
 Sisserskite, 127. 
 
 Skutterudite, 166. 
 
 Smaltite, Smaltine, 165. 
 
 Smectite, 307, 312. 
 
 Smithsonite, 156. 
 
 Snow, crystals of, 4. 
 
 Soapstone, 304, 454. 
 
 Soda nitre, 229. 
 
 Sodalite, 270. 
 
 Sodium, Compounds of, 228. 
 
 Sommite, 269. 
 
 Spaniolite, 136. 
 
 Spathic iron, 185. 
 
 ' Spear pyrites, 174. 
 
 Speckstein, v. Steatite. 
 
 Specular iron, 176, 455. 
 
 Speculum metal, 144. 
 
 Spelter, 158. 
 solder, 144. 
 
 Spessartite, 258. 
 
 Spherosiderite, 186. 
 
 Sphalerite, 154. 
 
 Sphene, 290. = 
 
 Spherocobaltite, 168. 
 
 Spilite, 451. 
 
 Spinel, 194, 204. 
 
 Spinthere, v. Titanite. 
 
 Spodumene, 248. 
 
 Stalactite, 216. 
 
 Stalagmite, 216, 482. 
 
 Stannite, 159. 
 
 Staurolite, Staurotide, 291. 
 
 Steatite, 304. 
 
 Steatyte, 454. 
 
 Stephanite, 119, 121. 
 
 Stercorite, 2381. 
 
 Sterlingite, ». Damourite. 
 
 Sternbergite, 118. 
 
 Stibnite, 100. 
 
 Stilbite, 302. 
 
 Stilpnomelane, 307. 
 
 Stinkstone, 217. 
 
 Stolpenite, 307. 
 
 Stolzite, 151. 
 
 Strakonitzite, 295. 
 
 Stratopeite, 316. 
 
 Strengite, 185. 
 
 Strigovite, 316. 
 
 Stromeyerite, 118. 
 Strontianite, 223. 
 
 Strontium, Compounds of, 220. 
 
 Struvite, 231. 
 
 Stiibelite, 316. 
 Stylotypite, 136, 149. 
 Succinum, 325. 
 Sulphate, Aluminum, 197, 198. 
 
 Ammonium, 231. 
 
 Barium, 220. 
 
 Calcium, 210, 211. 
 
 Cobalt, 168. 
 
 Copper, 187, 188. 
 
 Iron, 182. 
 
 Lead, 150. 
 
 Magnesium, 205. 
 
 Nickel, 168. 
 
 Potassium, 227. 
 
 Sodium, 226, 227. 
 
 Strontium, 222. 
 
 Uranium, 171. 
 
 Zinc, 156. 
 
 Sulphide, Antimony, 100. 
 Arsenic, 99. 
 Bismuth, 102. 
 Cadmium, 159. 
 Cobalt, 164. 
 
 Copper, 182, 138, 184. 
 
 Iron, 172, 174. 
 
 Lead, 145, 149. 
 
 Manganese, 188. 
 
 Mercury, 128, 150. 
 
 Molybdenum, 96. 
 
 Nickel, 164. 
 
 Ruthenium, 127. 
 
 Silver, 117, 118. 
 
 Tin, 159. 
 
 Zinc, 154, 155. 
 Sulphur, Native, 37, 94. 
 Sulphuret, see Sulphide. 
 Sulphuric acid, 96. 
 Sulphurous acid, 96. 
 Sunstone, 277, 279. 
 Susannite = Rhombohedral Lead- 
 
 hillite. 
 
 Sussexite, 206. 
 
 Syenites, 445. 
 
 Syenyte, 445. 
 
 gneiss, 446. 
 
 Sylvanite, 116, 118. 
 
472 GENERAL INDEX. 
 
 Sylvine, Sylvite, 224. 
 Syngenite, 227. 
 Szaibelyte, 206. 
 
 Tabasheer, 241. 
 
 Tabular spar, 244. 
 
 Tachhydrite, 205. 
 
 Tachyaphaltite, 260. 
 
 Tachylyte, 452. 
 
 Tagilite, 139. 
 
 Talc, 304. 
 
 Talcose schist, 454. 
 slate, 441. 
 
 Tantalates, 170, 184, 202, 214. 
 
 Tantalite, 184. 
 Tapalpite, 118. 
 Tasmanite, 326. 
 Tellurate, Bismuth, 102. 
 Mercury, 129. 
 Telluride, Bismuth, 102. 
 Gold, 115, 116, 118. 
 Lead, 149. 
 Mercury, 129. 
 Silver, 118. 
 Tellurite, 96. 
 Tellurium, Bismuthic, 102. 
 Foliated, v. Nagyagite. 
 Graphic, 118. 
 Native, 96. 
 Tellurous acid, 96. 
 Tengerite, 203. 
 Tennantite, 135. 
 Tenorite, 137. 
 Tephroite, 256. 
 Terenite, 312. 
 Teschemacherite, 281. 
 Teschenite, 448. 
 Tetradymite, 102. 
 Tetrahedrite, 121, 135. 
 Thenardite, 227. 
 Thermonatrite, 230. 
 Thomsenolite, 197. 
 Thomsonite, 298. 
 Thorite, 296. 
 Thraulite, 316. 
 Thulite, 263. 
 Thumite, 264. 
 Thuringite, 319. 
 Tiemannite, 129. 
 Tile ore, 187, 160. 
 Till, 429. 
 Tin, Native, 159. 
 Tin ore, Tin stone, 160. 
 
 Tin pyrites, 159. 
 Tinkal, 227. 
 Titanic iron, 178, 456. 
 Titanite, 290. 
 Titanium, Ores of, 162. 
 Tiza, v. Ulexite. 
 Tocornalite, 121. 
 Tonalyte, 447. 
 Topaz, 286. 
 
 False, 235. 
 
 Oriental, 193. 
 Topazolite, 258. 
 Torbanite, 325, 329. 
 Torbernite, 170, 139. 
 Touchstone, 237. 
 Tourmaline, 282. 
 Trachydoleryte, 447. 
 Trachyte, 442. 
 Tractolyte, 450. 
 Trap, 451. 
 Traversellite, 295. 
 Travertine, 482. 
 Tremolite, 249. 
 Trichites, 416. 
 Triclasite, 315. 
 Tridymite, 88, 241. 
 Tripestone, 212. 
 
 Triphylite, Triphyline, 184, 190. 
 
 Triplite, 191. 
 Triploidite, 191. 
 Tripolite, 241. 
 Tripolyte, 430. 
 Tritomite, 296. 
 Trégerite, 171. 
 
 Troilite, 175. 
 
 Trona, 280. 
 
 Troostite, 157. 
 Tscheffkinite, 203, 291. 
 Tschermakite, v. Oligoclase. 
 Tschermigite, 198, 231. 
 Tufa, Tuffe, 428. 
 
 Tufa, Calcareous, 216. 
 Tungstate, Copper, 138. 
 
 Iron, 183. 
 
 Lead, 151. 
 
 Lime, 212. 
 Tungstic ochre, 97. 
 Tungstite, 97. 
 
 Turgite, 182. 
 Turquois, 200. 
 Tyrolite, 139. 
 
 Ulexite, 212. 
 
GENERAL INDEX. AY 
 
 Ulmannite, 166. 
 Ultramarine, 270. 
 Unakyte, 446. 
 Unghwarite, 307. 
 Unionite, v. Zoisite. 
 Uraconise, Uraconite, 171. 
 Uralite, 247. 
 
 Uranin, Uraninite, 169. 
 Uranite, 170. 
 Uranium, Ores of, 169. 
 Uranmica, 170. 
 Uranochalcite, 171. 
 Uranocircite, 171. 
 Uranospinite, 170. 
 Uranotantalite, 170. 
 Uranvitriol, 171. 
 Urpethite, 324. 
 
 Valentinite, 101. 
 Vanadate, Copper, 139. 
 Lead, 152. 
 -Vanadinite, 152. 
 Variolyte, 449. 
 Variscite, 200. 
 Vauquelinite, 151. 
 Velvet copper ore, 138. 
 Venerite, 319. 
 Venice white, 221. 
 Verd-antique, 308, 454. 
 Oriental, 415. 
 
 Verde di Corsica duro, 449. 
 
 Vermiculite, 317. 
 Vermilion, 129. 
 Vesuvianite, 261. 
 Veszelyte, 139. 
 Villarsite, 296. 
 Viridite, 317. 
 Vitreous copper, 182. 
 silver, 117. 
 Vitriol, Blue, 137. 
 Green, 182. 
 Tron, 182. 
 White, 156. 
 Vivianite, 184. 
 Voglianite, 171. 
 Voglite, 171. 
 Volborthite, 139. 
 Volknerite, 194. 
 Voltaite, 182. 
 Voltzite, 155. 
 Vorhauserite, 308, 
 Vulpinite, 212. 
 
 Wacke, 428. 
 
 Wad, 190. 
 
 Wagnerite, 206. 
 
 Walchowite, 325. 
 Walpurgite, 171. 
 Warringtonite, v. Brochantite. 
 Warwickite, 206. 
 Washingtonite, 178. 
 
 Water, 4, 281. 
 
 | Wavellite, 201. 
 
 Websterite, 199. 
 Webhrlite, 102. 
 Wernerite, 268. 
 Westanite, v. Fibrolite. 
 Wheel-ore, 136. 
 Whetstone, 486, 453. 
 White vitriol, 156. 
 
 arsenic, 99. 
 Whitneyite, 185. 
 Wichtine, Wichtisite, 252. 
 Willcoxite, 320. p 
 Willemite, 157, 256. 
 Williamsite, 308. 
 Wilsonite, 312. 
 Winkworthite, v. Howlite. 
 Witherite, 221. 
 Wittichenite = Cu,Bi8s. 
 Wittingite, 316. 
 Wohlerite, 256, 260. 
 Wolfram, Wolframite, 183. 
 Wollastonite, 244. 
 Wollongongite, 326. 
 Wood-opal, 240. 
 Wood tin, 160. 
 Woodwardite, near Cyantrochite. 
 Wulfenite, 151. 
 Wurtzite, 155. 
 
 Xanthophyllite, 320. 
 Xanthosiderite, 182. 
 Xenotime, 208. 
 Xylotine, 299. 
 
 Yenite, 263. 
 Youngite, 155. 
 Ytter-garnet, 258. 
 Yttrium ores, 201. 
 Yttrocerite, 201. 
 Yttroilmenite, 170. 
 Yttrotantalite, 202. 
 
 Zaftre, 168. 
 31 
 
A” 
 
 Zaratite, 168. 
 Zeagonite, 296. 
 
 Zeolite Section, 297. 
 Zepharovichite, 201. 
 
 Zeunerite, 170. 
 
 Zietrisikite, 324. 
 
 Zinc, ores of, 154. 
 blende, 154. 
 
 GENERAL INDEX, 
 
 | Zinkenite, 149. 
 Zinnwaldite, 268. 
 Zippeite, 171. 
 Zircon, 259. 
 Zirconite, 260. 
 Zircon-syenyte, 446, 
 
 , | Zéblitzite, 309. 
 
 Zoisite, 268. 
 
 bloom, ‘v. Hydrozincite. Zonochlorite, 296. 
 
 Zinc ore, red, 155. 
 Zincite, 155. 
 
 Zorgite, 149. 
 Zwieselite, v. Triplite. 
 
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