80 MINERALS OF CHILE. 



Oxide of iron 32.10 



Oxide of manganese 30.50 



Lime 2.75 



Magnesia trace. 



Carbonic acid 32.80 



Not dissolved 35 



98.50 

 OXLDE OF MANGANESE. 



This is found at Arqueros, near the silver-veins in secondary 

 porphyry. The varieties that appear to exist there are psilom- 

 elane and pyrolusite. 



SMALTINE— ARSENICAL COBALT. 



This mineral of cobalt is found in Atacama, in transition 

 and secondary formation, often accompanying ruby-silver, na- 

 tive arsenic, and arsenical nickel. It occurs both crystallized 

 and massive, possessing all the properties peculiar to this min- 

 eral. The composition of the specimen examined was 



Arsenic 70.85 



Cobalt 24.13 



Iron 4.05 



Copper 41 



Nickel 1.23 



Sulphur 08 



100.75 

 The formula of the mineral is Co As, part of the cobalt 

 being frequently replaced by other metals. 



COBALTINE — SULPHO-ARSENICAL COBALT. 



This is found in Coquimbo, in small, brilliant octahedral 

 crystals, with truncated corners. It is also found granular and 

 massive, in pieces of considerable size. The specimens from 

 the mines of Yolcan and San Simon are of a steel-gray color, 

 imperfect foliated structure, metallic luster, hard, amorphous, 

 accompanied with arseniuret of copper. It is also found asso- 

 ciated 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 



Cobalt 34.12 



Iron 3.01 



The formula is Co 1 S 2 +Co As. 10L18 



