MINERALS OP CHILE. 59 



of the Andes, about forty miles east of Chilian, where it exists 

 to the depth of thirty-five feet, in a very fine yellow clay 

 mixed with black sand. The yield of gold is not very great. 



NATIVE COPPER. 



This is very commonly found in all the copper-mines of 

 Chile. In one specimen from Andacollo (Coquimbo) it was 

 found crystallized in modified octahedrons ; it is very com- 

 monly associated with the red oxide of copper, as beautifully 

 show j by a specimen from Illapel (Coquimbo). It is also 

 found in quartz at Andacollo (Coquimbo). Others of the speci- 

 mens came from San Jose, San Pedro Nolasco, Hinchado, 

 Higuera, and Aconcagua. 



RED COPPER. 



This mineral is found beautifully crystallized in octahedrons 

 more or less modified. The most beautiful specimens of this 

 description are from Coquimbo; other specimens are massive 

 and granular. 



Its hardness is 3.5; specific gravity 5.9. Its color is vari- 

 ous shades of bright-red, and the crystals are transparent, 

 although from the exceeding intensity of their color they 

 must be examined by a strong light. 



This mineral is quite brittle, and is composed of 



Copper 88.88 



Oxygen...... 11.12 



Formula is Cu2 0. 100 - 00 



It sometimes forms veins coated with green and blue sili- 

 cates of copper in the mines of Camarona and Cortadera, in 

 the province of Coquimbo. In the Andacollo mine it is found 

 pure and abundant below the oxysulphuret, resting on metallic 

 copper, with which it is very commonly mixed. Aconcagua 

 also afforded specimens. At Illapel it is found containing 

 native silver. 



CAPILLARY RED COPPER. 



This beautiful form of the oxide of copper is found in fine, 

 delicate rhombohedral crystals. It was found in the cavities 

 of massive specimens of the red copper from Aconcagua. The 

 crystals are as small as the finest hair, and sometimes half an 



