enargite

{{Infobox mineral | name = Enargite | category = Sulfosalt mineral | boxwidth = | boxbgcolor = | image = Enargite-122840.jpg | imagesize = 260px | caption = | formula = Cu3AsS4 | IMAsymbol = Eng | strunz = 2.KA.05 | system = Orthorhombic | class = Pyramidal (mm2) H-M symbol: (mm2) | symmetry = Pmn21 | unit cell = a = 7.407(1), b = 6.436(1) c = 6.154(1) [Å]; Z = 2 | color = Grayish black to iron black; gray to pale pink-brown, deep red internal reflections in polished section | habit = Tabular to prismatic crystals, striated parallel to {001}; massive | twinning = Twin plane {320} common, rarely as interpenetrating pseudohexagonal trillings | cleavage = Perfect on {110}, distinct {100} and {010} | fracture = Uneven | tenacity = Brittle | mohs = 3 | luster = Metallic to dull | polish = | refractive = | opticalprop = | birefringence = | dispersion = | pleochroism = | fluorescence= | absorption = | streak = Black | gravity = 4.4 to 4.5 | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Opaque | other = | references = }} Enargite is a copper arsenic sulfosalt mineral with formula Cu3AsS4. It takes its name from the Greek word '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.