Enargite on Pyrite

A columnar 2cm enargite centers this complex of distorted crystals which also have an area with a herringbone pattern. The matrix of enargite hosts a mound of small pyrites. It appears some exposure to the elements dulled the surfaces a bit. Ex Jim and Paula Wilson

Locality: Butte Mining District, Silver Bow County, Montana

Composition: copper arsenic sulfosalt and iron sulfide