A Geoscience Digital Image Library

TitleChalcocite from Butte, Montana
DescriptionChalcocite, Cu2S (copper sulfide), is an important copper mineral ore. Although relatively rare, it is one of the most profitable copper ore minerals because it contains lots of copper and is easy to process. Just like native copper deposits, the richest chalcocite deposits have probably been mined out, so most copper today comes from other minerals. This specimen, from the famous mining district near Butte, Montana, is about 9 cm across. If you look closely at it, you will see that the gray chalcocite is accompanied by a small amount of golden yellow chalcopyrite (CuFeS2), and some bornite (purplish tarnish), Cu5FeS4.
LocationUSA ▹ Montana. Near Butte.
PhotographerNessa Eull. 2001-07-10.
CollectionUniversity of North Dakota Mineralogy Collection #155.
Key wordschalcocite, Montana
Tech details718 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens.
GeoDIL number1085