Enargite

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Enargite
Category Minreral: Sulfide
Chemical formula Cu3AsS4
Identification
Molecular Weight 393.82 gm
Color Greyish Black to Black
Crystal habit massive to well crystaline
Crystal system Orthorhombic
Cleavage Perfect [110], Distinct [100] & [010]
Fracture uneven
Tenacity Brittle
Mohs Scale hardness 3
Luster Metallic
Ultraviolet fluorescence None
Streak Black
Specific gravity 4.4 to 4.5
Diaphaneity Opaque
References [1][2][3]

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. It is a medium to low temperature hydrothermal mineral occurring with quartz, pyrite, as well as other copper sulfides. 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

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