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Enargite

Enargite
2cm specimen of Enargite crystals on pyrite from Butte, Montana
General
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.

Additional recommended knowledge

References

^ http://www.mindat.org/min-1380.html Mindat
^ http://webmineral.com/data/Enargite.shtml Webmineral
^ http://mineral.galleries.com/minerals/sulfides/enargite/enargite.htm Mineral galleries

Categories: Copper minerals | Sulfosalt minerals | Sulfide minerals