Enargite

[2] It is a medium to low temperature hydrothermal mineral occurring with quartz, pyrite, sphalerite, galena, bornite, tetrahedriteā€“tennantite, chalcocite, covellite and baryte.

[4] It occurs in the mineral deposits at Butte, Montana, San Juan Mountains, Colorado and at both Bingham Canyon and Tintic, Utah.

It is also found in the copper mines of Canada, Mexico, Argentina, Chile, Peru, and the Philippines.

Enargite was originally described as a new species from the copper mines of the San Francisco vein, Junin Department, Peru.

[2][4] Enargite is related to lazarevicite (named after M. Lazarevic), which has the same chemical formula, but cubic crystalline structure.