70 MINERALS OF CHILE. 



high metallic luster. The only analysis we have of this variety 



of bismuth-silver is one by M. Domeyko ; the following are the 



results : 



Silver 60.1 



Bismuth 10.1 



Copper 7.8 



Arsenic 2.8 



Gangue 19.2 



100.0 

 HORN-SILVER, CHLORIDE OF SILVER. 



This is one of the most abundant silver minerals in Chile, 



as it is found there in quantities far exceeding any thing that 



is elsewhere known. It is commonly massive, resembling wax 



of a grayish color, when the surface is freshly broken ; but 



soon tarnishes on the exposure to light, acquiring a purplish 



tint. Sometimes it is of a greenish tint. Its luster is resinous ; 



easily cut with a knife ; specific gravity 5.4. It possesses all 



the properties of the artificial chloride. Its composition is 



Silver 75.33 



Chlorine 24.67 



Formula, Ag 01. 100 - 00 



Several very fine specimens were brought by the expedition 

 from the Chanarcillo, Yalenciana mines, in Atacama, and other 

 localities. 



BROMIC SILVER. 



This compound of silver is likewise found in Chanarcillo, 

 and in many respects resembles the chloride ; its color is 

 greener, and it never occurs in such masses as the chloride. 

 It is equally soft, having a little higher specific gravity — 5.8. 

 Composition when pure : 



Silver 58 



Bromine 42 



Formula, Ag Br. 

 EMBOLITE, CHLORO-BROMIDE OF SILVER. 



This mineral is found both crystallized and massive in 

 several of the mines of Chile, in the provinces of Atacama 

 and Coquimbo. It is less abundant than the chloride, although 

 more so than the bromide. Externally it is greenish, internally 



