THE MINERALS OF CHILE. 103 



consideraUe size. The specimens from tlie mines of Volcan and San Simon are of a steel-gray- 

 color, imperfect foliated structure, metallic lustre, hard, amorphous, accompanied with arseniuret 

 of copper. It is also found associated with copper pyrites ; and there is one vein of it running 

 parallel to a vein of copper pyrites. Its composition is — 



Arsenic - - - - - - - 44.23 



Sulphur 19.82 



Cohalt - - 34.12 



Iron - - 3.01 



101.18 



The formula is CqI S' + Co As. 



Cohalt Bloom — Arseniate of Cobalt. — It is found in all the veins containing the arseniurets 

 of cobalt, and also in most of the silver veins, hut never in any considerable quantity. At 

 Arqueros it is found with the native amalgam, and with native and horn silver, in the mines 

 of Argua Amarga, Chaiiarcillo, Punta Brava, Tunas, &c. It is crystallized in radiating crys- 

 tals of a peach-blossom color, and consists of — 



Arsenic acid ______ 38.21 



Oxide of cobalt ------ 35.92 



Oxide of nickel ------ .08 



Oxide of iron ------ 2.13 



Lime ---___- .32 



Water ------- 23.16 



99.82 



The formula is Co^ Is -(- 8 fl. 

 NICKEL. 



Nickel Glance — Arsenical Nickel. — This is found in Atacama. It is of a steel-gray color ; 

 freshly broken surfaces soon tarnish. No analysis was made of this mineral from the above 

 locality ; and we know of none that has been made. When pure, its constitution should be — 

 Arsenic ------- 45.16 



Sulphur ------- 19.33 



Nickel - - - - - - - 35.51 



100.00 



Its formula is Ni S^ -{- Ni As. Other metals, especially iron, frequently replace the nickel 

 to some extent. 



BISMUTH. 



Native Bismuth. — This is found, alloyed with silver, in the San Antonio mine, Atacama. 

 The mineral has already been described, under the head of the silver minerals. It commonly 

 contains from 14 to 15 per cent, of bismuth. 



ANTIMONY. 



Native Antimony. — This is found in considerable quantity in the silver veins in the mines 

 of Carriso. It is disseminated in small irregular veins, and inlaminas, like galena. The most 

 constant companions of it are native silver, ruby silver, gray antimony, gra.y copper, &c. 

 The gangue is carbonate of lime and heavy spar. 



