Page:Encyclopædia Britannica, Ninth Edition, v. 16.djvu/419

MINERALOGY 401 acid with effervescence. C. c. : sulphate of lead 57 6, oxide of lead dyeing, and in manufacturing ink, Prussian blue, and sulphuric 42 -4. Leadhills ; rare. acid. HYDROUS SULPHATES. 318. MIRABILITE (Glauber Salt), Na.,S + 10H 2 . Oblique prismatic, C 72 15 . Cl. orthodiagonal ; fracture conchoidal. H. -1 5 to 2 ; G. -T4 to 1 5. Pellucid and colour less. C.c. : 19 2 soda, 24 8 sulphuric acid, and 56 water. As an efflorescence in quarries, on old walls, or on the ground ; in the waters of lakes and springs in Russia and Egypt, and on Vesuvius on lava. 319. GYPSUM, CaS + 2H 2 . Oblique prismatic, C 80 57 . The most common forms are ooPlll30 ; P 138 40 ; - P143 30 ; and ooP c oo. Two common combinations are ooP(/), ooP c oo (p), - P (I) (fig. 129), and this with P. Lenticular crystals often occur ; hemitropes frequent (figs. 161, 150, 151); also granular, compact, fibrous, scaly, or pulverulent. Cl. clinodiagonal perfect, along P much less perfect ; sectile ; thin plates flexible. H. =1 5 to 2 (lowest on P) ; G. =2 2 to 2 4. Transparent or translucent ; vitreous, on cleavage pearly or silky. Colourless, and snow-white, but often red, grey, yellow, brown, and more rarely greenish or bluish. In the closed tube yields water. B.B. becomes opaque and white; soluble in 400 to*500 parts of water, scarcely more so in acids. C.c.: 46 "5 sulphuric acid, 32 - 6 lirne, and 20 - 9 water. Transparent crystals, or Selenite, occur in the salt-mines of Bex in Switzerland, of the Tyrol, Salzburg, and Bohemia, in the sulphur- mines of Sicily, at Lockport in New York, in porphyry at Gourock, in the clay of Shotover Hill near Oxford, at Chatley near Bath, and many other localities. Fibrous gypsum at Campsie, Matlock in Derbyshire, and at Ilfeld in the Harz. Compact gypsum in whole beds in many parts of England, Germany, France, and Italy, at Vol terra in Tuscany (Alabaster) often with rock-salt. The finer qualities (or alabaster) are cut into various ornamental articles. Cl. 320. KIESERITE, Rhombic, but chiefly massive. G. =2 52. Pellucid; greyish white. C.c. : magnesia 29, sulphuric acid 58, water 13. In beds at Stassfurt. 321. EPSOMITE (Epsom Salt), MgS + 7H 2 . Right prismatic. P mostly hemihedric ; ooP 90 38 . ooP (J/), oo Poo (o), P (1) (fig. 399). Granular, fibrous, or earthy. braehydiagonal, perfect. H. = 2 to 2 - 5 ; G. = 1 75. Pellucid ; vitreous ; and white. Taste bitter. C.c.: 16 32 magnesia, 32 53 sulphuric acid, and 51 15 water. Efflorescence on various rocks, as at Hurlet near Paisley, Idria, Montmartre, and Freiberg ; on the gronnd in Spain and the Russian steppes ; in mineral waters, as at Epsom in Surrey, Saidschitz and Seidlitz in Bohemia. Used in medicine. 322. GOSLARITE 7H 2 . Right prismatic. (White Vitriol), ZnS ooP 90 42 ; isomor- M phous with epsomite. ooP, ooPoo , P (M, o, I) (fig. 399). Mostly granular or stalactitic ; Fi S- 3 99 ( S P- 321). reniform and incrusting. Cl. braehydiagonal, perfect. H. =2 to 2 5 ; G. =2 to 2*1. Pellucid ; vitreous. White, inclining to grey, yellow, green, or red. Taste nauseous-astringent. C.c. : 28 2 zinc oxide, 27 9 sulphuric acid, and 43 - 9 water. Holywell in Flintshire, Cornwall, Ram- melsberg near Goslar in the Harz, Falun, Schemnitz. Used in dyeing and medicine. 323. MORENOSITE, Acicular, fibrous, and as an efflorescence. H. =2 to 2 25; G. =2. Lustre vitreous. Apple-green ; streak white. Soluble. Mor- vern in Argyllshire, Cape Ortegal (Spain), Lake Huron, Pennsylvania. 324. MELANTERITE (Green Vitriol, Cop peras), FeS + 7H 2 . Oblique prismatic, C 75 45 . ooP (/) S2 22 ; -P (P) 101 34 ; Poo(o) 67 30 (fig. 400); chiefly stalactitic, reniform, or in crusts. Cl. basal, perfect; prismatic less so. Translucent, rarely transparent ; vitreous. Leek- orinountain-green, often with a yellowish coating; streak white. C.c. : 26 protoxide of iron, 29 sulphuric acid, and 45 water. Hurlet near Paisley, Bodenmais, Rammelsberg, Falun, Schemnitz, Bilin. Used in 325. SMIKITE, il Stalactitic aggregates. Rose to white. Felsobanya (Hungary). 326. MALLARDITE, MnS-f-7H 2 . Crystalline foliated masses ; apparently oblique prismatic. Lucky Bay mine in Utah. 327. BIEBERITE (Cobalt Vitriol), Co S + 7H 2 . Oblique prismatic ; usually stalactitic, or an efflorescence. Pale rose-red. C.c. : 20 cobalt oxide, 4 magnesia, 29 sulphuric acid, and 47 water. Bieber near Haiiau, and Leogang. 328. ALUNOGENE (Hair-Salt), Al a S + 18H 2 . Capillary or acicular, in crusts or reniform masses. H. = 1 5 to 2; G. =1 6 to 17. Silky. White, inclining to green or yellow. C.c. : 36 sulphuric acid, 15 4 alumina, 48 6 water. Volcanoes of South America, in coal and lignite in Germany, and on old walls. 329. ALUMINITE ( JVebsleritc), A1 2 S"+9H. Reniform, and very fine scaly, or fibrous. Fracture earthy ; sectile or friable. H. = 1 ; G. = 1 7. Opaque ; dull or glimmering ; snow-white or yellowish white. C.c.: 29 8 alumina, 23 2 sulphuric acid, and 47 water. Newhaven in Sussex ; Epernay, Auteuil, and Lunel Vieil in France ; Halle and Mori in Prussia. Felsdbanyile, from Hungary, in rhombic tubes, is similar, but has 10 per cent, of water. Fl S- 40 < S P- 324 )- H. =- 2 ; G. = 1 8 to 1 9. 330. COQUIMBITE, Fe 2 3S + 9H 2 . Hexagonal. P 58. Crystals OP; with P and P; usually granular. Cl. o>P, imperfect. H. =2 to 2 5 ; G. -2 to 21. White, also brown, yellow, red, and blue. C.c. : 28 5 iron peroxide, 42-6 sulphuric acid, and 28 9 water. Copiapo in Chili, and Calaina in Bolivia. 331. COPIAPITE, 2Fe 2 5S +13H 2 . Six-sided tables, but system uncertain ; also granular. Cl. per fect. Translucent; pearly. Yellow. C.c.: 34 iron peroxide, 42 sulphuric acid, and 24 water. Copiapo in Chili. Also radiated- nbrous masses, dirty greenish yellow, incrusting the former, with 32 sulphuric acid and 37 water. Both probably mixtures. Fibroferrite, also from Chili, and Yellow Iron Ore, from the brown coal at Kolosoruk in Bohemia and Modum in Norway, are both reniform, or compact and earthy. H. =2 5 to 3 ; G. =27 to 2 9. Colour ochre-yellow. Apatclite, reniform-earthy, yellow, from Auteuil near Paris, is similar ; also Vitriol Ochre from Falun. Misy, from Rammelsberg in the Harz, containing sulphates of iron, copper, zinc, and other metals, is a product of decomposition. 332. PISSOPHANE, (Al a Fe 2 ). j S +15H 2 . Stalactitic ; fracture conchoidal ; very easily frangible. H. = 2 ; G. = 1 9 to 2. Transparent or translucent ; vitreous. Olive-green to liver-brown ; streak greenish white to pale yellow. C.c. : 7 to 35 alumina, 10 to 40 iron peroxide, 12 sulphuric acid, and 41 water. Saalfeld and Reichenbach in Saxony. Carphosiderite, reniform, opaque, resinous, and straw-yellow, with a greasy feel, is related. H. = 4 5 ; G. = 2 - 5. Consists of hydrous sulphate of iron. Labrador. , 333. CHALCANTHITE, CuS + 5H 2 . Anorthic. oopoo (n) : oopoo (r) 79 19 . P (P): oo P (T) 127 40 . P : n 120 50 . P : r 103 27 . ooF (T) : oo P (M) 123 10 (fig. 401). Generally incrusting. Cl. T and M, im perfect. II . = 2-5; G. =2-2. Blue. C.c.:32 protoxide of copper, 32 sulphuric acid, 36 water. Cornwall, Wicklow, Hungary, Tyrol, Falun, and on lava of Vesuvius. 334. BKOCHANTITE, CuS + 3CuH 2 . Right prismatic, ooP 104 32 ; Poo 152 37 ; and ooPoo ; also reniform. Cl. braehydiagonal, perfect. H. 3 5 to 4; G. =375 to 39. Transparent or trans lucent ; vitreous. Emerald or blackish green; streak bright green. C.c.: 70 Fig. 402 (sp. 334). copper protoxide, 18 sulphuric acid, and 12 water. Sandlodge (Unst), Roughton Gill in Cumber- XVI. -- 51

Fig. 401 (sp. 333).