Formula: Cu3AsS4 Orthorhombic
Description:
Enargite is a rare hydrothermal mineral found associated with other copper minerals.
FOREST COUNTY: Small grains of enargite occur with bornite and digenite replacing chalcopyrite at the Crandon deposit near Little Sand Lake. (Lambe and Rowe, 1989)
GRANT COUNTY: Tiny tabular prismatic crystals of enargite was found at the Piquette #2 mine in the SW NE Sec. 36 T.3N R.3W. Here it occurs in vugs perched on sphalerite and chalcopyrite and associated with calcite, marcasite, pyrite, galena and millerite. The enargite crystals are up to 0.5 mm. long and are dominated by the {110}, {100} and {001} forms with subordinate {010} and {011} forms (Heyl, 1964).
IOWA COUNTY: Small prismatic crystals, likely enargite, occur at the Ivey mines near Mineral Point (Heyl, 1964).