COPPER PYRITES. 

 Freiberg, in Saxony ; Querbach, in Silesia ; 



, Toacbimstahl, in Bohemia ; Saalfield, in 

 Thuringia ; in Swabia, Styria, Hessia. Alle- 

 Awnt, in Daupbine; and Aragon, in Spain. 



Copper Nickel may be distinguisbed from 

 ^opper, to Avhicb it bears a striking resem- 

 nlance, by its brittleness. The name is de- 



,1 rived from its copper-red colour, and its 



\ constituent parts. 

 Brit. Mus., Case 4. 



: M. p. G. Principal FlooV, Wall-cases 9 



I (British) ; 20 (Foreign). 



j Copper Pyrites, J(i?«esow, P/a7Z?>s. See 



,: Chalcopyrite. 



I Copper Vitriol, Jameson. See Cyano- 



' SITE. 



!j Copper Ura>'ite, Naumann. See Chal- 

 colite. 



Copperas, Dana. Oblique: primary 

 form an oblique rhombic prism. It occurs 



[ massive, pulverulent, botryoidal, reniform, 



; stalactitic, and crystallized. Colour various 



: shades of green, but generally of a yellow 

 or yellowish -brown col our externally. Trans- 



j kicent. Lustre vitreous. Streak white. 



I Taste metallic and astringent. Brittle. 



i Fracture conchoidal, H. 2. S.G. 1'83. 



Fig. 131. 



Comp. Heptahydrated protosulphate of 



iron or Fe S + 7 H = sulphuric acid 28'9, pro- 

 toxide of iron 25-7, water 45'4 = 100-0. 



BB on charcoal, becomes magnetic ; with 

 borax affords a green glass. On exposure 

 to the air, becomes covered with a yellow 

 powder, which is sulphate of peroxide of iron. 



Soluble in 1-6 parts of cold, and 0-3 of 

 boiling water, and the solution turns black 

 on the addition of tincture of galls. 



This salt is generally produced by the de- 

 composition of Iron Pyrites ; and in Great 

 Britain is found in Lower Bagshot Clays in 

 Branksea Island, in Dorsetshire ; in Fullers 

 Earth at Widcombe, near Bath ; in Alum- 

 shale at Whitby, in Yorkshire; and Hurlet, 

 near Paisley ; at Castleton, in Derbyshire, 

 in small crystals ; and in some of the 

 Gwennap Mines in Cornwall. It also occurs 

 in the Rammelsberg Mine, near Goslar, in 

 the Harz; at Gieshiibl ; near Bodenmais, 

 in Bavaria ; at Schwartzenberg, in Saxonj' ; 

 and Schemnitz, in Hungary, and in the 

 United States at Copperas Mount, a few 

 miles east of Bainbridge, Ohio. 



Copperas is employed in dyeing and tan- 



CORACITE. 95 



ning, in the manufacture of writing-ink, of 

 Prussian blue, and sulphuric acid The re- 

 sidue of the latter process (colcothar of iron) 

 is used as a red paint, and, when washed, for 

 polishing glass, steel, &c. (See Vitriolite.) 



Brit. Mus., Case 55. 



31. P. G. Horse-shoe Case, No. 233. 



CoppERASiNE. The name proposed by 

 Prof. C. U. Shepard for a h3'drated ferrous 

 cuprous, and ferric sulphate from Ducktown 

 copper mine, in Eastern Tennessee. 



Coouimbite, Brooke ^ Milier, Dufrenoy. 

 Hexagonal ; occurs in prisms, with the ter- 

 minal edges deeply replaced, and in fine 

 granular masses. Colour violet-white, yel- 

 lowish, or brownish. Fracture conchoidal. 

 Taste astringent. H. 2 to 2o. S.G. 2 

 to 2-1. 



Comp. Tersulphate of 



iron, or Fe fe^ + 9 



H = peroxide of iron 28 



5, sulphuric acid 



42-7, water 28-8 = 100-0. 





Analysis by H. Rose : 





Peroxide of iron . 



. 24-11 



Alumina 



. 0-92 



Sulphuric acid 



. 43-55 



Lime . 



. 0-73 



Magnesia 



. 0-32 



Silica . 



. 0-31 



Water . . 



. 30-10 ■ 



100-04 

 Dissolves in muriatic acid or in cold 

 water, with the exception of the silica ; the 

 latter solution deposits a large quantity of 

 peroxide of iron on boiling. 



Coquimbite appears to have been pro- 

 duced by the weathering of Iron Pyrites. It 

 is found in crystals, and massive, with other 

 ores of iron, in a felspathic rock, in the pro- 

 vince of Coquimbo, about half a day's 

 journey from Copiapo, in Chili. It also 

 forms the greater part of a large hill near 

 Calama in Bolivia. 



Coracite, Leconte. An amorphous mine- 

 ral, resembling Pitch-blende, of a pitch- 

 black colour. H. 3. 



Analysis by J. D. Whitney : 



Peroxide of uranium . . 72-60 

 Oxide of lead . . . 6-56 



Lime 5*99 



Peroxide of iron . . . 2-74 

 Alumina .... I-IO 



Silica 5-33 



Water 5-68 



100-00 

 BB gives the action of uranium with the 

 fluxes. On account of the read}' solubility 



