COPPER ORES. 49 



the following are a few examples of the position of certain 

 deposits. 



In the Eastern States there are deposits in the New Eed 

 Sandstone, also in the Carboniferous Limestone and Silurian 

 rocks. In the Lake Superior district, where so much 

 native copper is found, deposits occur in sandstones and 

 shales, underlying greenstone, &c. There are also lodes 

 running through the various strata. Deposits of ruby copper 

 ore occur in Arizona between quartzose and hornblendic 

 rocks and limestone. Lodes and deposits in Chili are 

 worked in hornblendic and felspathic quartz rocks. The 

 celebrated Burra Burra mine in Australia, from which 

 splendid lumps of malachite are familiar objects in museums, 

 consists of an immense irregular deposit of malachite and 

 other copper ores in limestone and harder rocks, as well as 

 in the soil. Copper deposits occur elsewhere in schistose, 

 hornblendic, quartzose rocks, &c., and pyrites-bearing lodes 

 through rocks of various ages. 



Copper sulphides (with or without antimony, arsenic, &c.) 

 often occur in gold and silver-bearing lodes ; and, therefore, 

 though neither free gold nor a silver compound may be 

 noticed on the outcrop, assays should certainly be made. 



1C 



