SILVER. 129 



Lustre unmetallic, of crystals adamantine ; often dull. 

 Color bright red to brownish reel, and brownish black. 

 Streak scarlet-red. Sub transparent to nearly opaque. II. = 

 22-5. G. =8-5-9. Sectile. 



Composition. Hg S, = Sulphur 13*8, mercury 86-2. It 

 often contains impurities. The liver 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 olf 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. 



Metacinnaoarite is the same compound with cinnabar, but differs in 

 crystallization ; it is from Redington Mine, Lake County, California. 



Guadalcazarite, of Mexico, is Hg S in which, a little 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 131 per cent, of chlorine, and 84*9 

 of mercury. 



Iodic 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 0< Te, from Magnolia dis- 

 trict, Colorado. 



General Remarks. — The following are the regions of the principal 

 mines of mercurv. At Idria, in Austria (discovered in 1407), 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 Estremadura, 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, 100 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 



