SILVER ORES. 327 



Antimonial Silver, consists simply of silver and antimony (77 parts 

 to 23,) and has nearly a tin-white color. Gr=9 4 — 9*8. Before the 

 Dlowpipe gray fumes of antimony pass off, leaving finally a globule of 

 silver. Called also Discrasite. 



Polybasite is near brittle silver ore in color, specific gravity, and com- 

 position, but contains some arsenic and copper, with 75*2 per cent, of 

 silver. The crystals are usually in tabular hexagonal prisms, without 

 cleavage. From Mexico and Peru. 



Miargyrite is an antimonial sulphuret of silver, containing but 36*5 

 per cent, of silver, and having a dark cherry-red streak, though iron- 

 black in color. Before the blowpipe gives off fumes of antimony and 

 an odor of sulphur ; and with soda, a globule is left which finally yields 

 a button of pure silver. 



Dark Red Silver Ore, and Light Red Silver Ore, are two allied orea 

 rhombohedral in their crystals. The former contains silver (59 per 

 cent.,) antimony, and sulphur, and has a color varying from black to 

 cochineal red, a metallic adamantine luster, and a red streak. H=25. 

 Gr=57— 59. 



The latter consists of silver, (65 4 per cent.) arsenic, and sulphur. 

 Its color and streak are cochineal red, H= 2 — 2*5. Gr=5'4 — 

 5*6. Before the blowpipe these species fuse easily, give off fumes, one 

 of antimony, the other of arsenic ; and finally a globule of silver is ob- 

 tained. They are abundant ores in Mexico, and occur also in Saxony, 

 Hungary, and Bohemia. These ores have been called ruby silver. 



Eucairite is a seleniferous ore of silver and copper occurring in black 

 metallic films. It gives before the blowpipe fumes of selenium, having 

 an odor like that of decaying horse-radish. From Sweden. Another 

 6eleniferous ore, from the Hartz, called selensilver, contains silver 

 and selenium, with a little lead, and crystallizes in cubes. 



Telluric Silver is a Russian ore, of a steel-gray color, containing 

 6ilver 62*8, and tellurium 37/2. Another variety contains 18 per cent, 

 of gold. Gr=83 — 88. With soda, silver is obtained. 



Xanthocone is another silver ore, containing silver (66'2 per cent.) 

 combined wkh sulphur and arsenic. Color dull red to clove-brown ; 

 powder yellow. 



horn silver. — Chlorid of Silver. 



Monometric. In cubes, with no distinct cleavage. Also 

 massive, and rarely columnar ; often incrusting. 



Color gray, passing into green and blue, and looking 

 somewhat like horn or wax. Luster resinous, passing into 

 adamantine. Streak shining. Translucent to nearly opaque. 

 Cuts like wax or horn. 



Composition : when pure, silver 75*3, chlorine 24*7. 

 Fuses in the flame of a candle, and emits acrid fumes. A£ 

 ords silver easily on charcoal. The surface of a plate of 

 ron rubbed with it is silvered. 



Describe horn silver. Of what does it consist 2 



