Enargite Locality: North Ore Body, Longfellow Mine, Red Mountain Pass, San Juan County, Colorado Specimen Size: 3.8 x 2.9 x 0.9 cm Largest Crystal: 7 mm © minclassics

Chemical Formula: Cu3AsS4
Locality: Butte, Montana, USA.
Name Origin: From the Greek enarges – “obvious.”

Enargite is a copper arsenic sulfosalt mineral with formula: Cu3AsS4. It takes its name from the Greek word enarge, “distinct.” Enargite is a steel gray, blackish gray, to violet black mineral with metallic luster. It forms slender orthorhombic prisms as well as massive aggregates. It has a hardness of 3 and a specific gravity of 4.45.

Enargite is dimorph of the tetragonal luzonite.

Physical Properties

Cleavage: {110} Perfect, {100} Distinct, {010} Distinct
Color: Steel gray, Blackish gray, Violet black.
Density: 4.4 – 4.5, Average = 4.45
Diaphaneity: Opaque
Fracture: Uneven – Flat surfaces (not cleavage) fractured in an uneven pattern.
Hardness: 3 – Calcite
Luminescence: Non-fluorescent.
Luster: Metallic
Magnetism: Nonmagnetic
Streak: black


Enargite Furtei Mine, Province of Medio Campidano, Sardinia – Italy Overall size: 140mm x 120 mm x 80 mm © minservice
PYRITE with Enargite Locality: Quiruvilca mine (Asarco mine), Quiruvilca District, Santiago de Chico Province, La Libertad Department, Peru Specimen Size: 5 x 5 x 2.5 cm © minclassics
Enargite Julcani District, Peru Overall size: 80mm x 55 mm x 40 mm © minservice
Julcani Mine, Julcani District, Angaraes Province, Huancavelica Department, Peru © 2003 John H. Betts