Enargite, mineral sulfosalt, copper arsenic sulfide (Cu3AsS4), which is sometimes a significant copper ore. Enargite is named in reference to its distinctive flawless cleavage, for the Greek term enargos, meaning “distinct”. To violet-black mineral with a metallic luster, it is a steel stone, blackish gold. It shapes both slender orthorhombian prisms and massive aggregates. It has a hardness of 3 and a gravity level of 4.45.
Crystals are sometimes coated with a skinny layer of Pyrite crystals, giving it a yellow appearance. Enargite is a dimorph of the tetragonal luzonite. Economically valuable deposits are found within the Balkans; at several places in Peru; Chuquicamata, Chile; and Butte, Mont. Enargite is dimorphous with the mineral Luzonite, which forms in tetragonal crystals. Often crystals are covered with a thin layer of Pyrite crystals which gives it a yellow appearance. Enargite is tetragonally luzonite dimorphic. Deposits of economic value are found in the Balkans; in many places in Peru; in Chuquicamata, Chile; and in Butte, Mont. Enargite is dimorphous with the tetragonal crystals produced by the mineral Luzonite.
Enargite is a hydrothermal mineral of medium to a low temperature that occurs with quartz, pyrite, sphalerite, galena, bornite, tetrahedrite-tennantite, chalcocite, covellite, and barite. It forms crystals of orthorhombic origin. Luzonite and Enargite often form together with different symmetry and cleavage patterns, in single altering crystals. It occurs in the mineral deposits at Butte, Montana, San Juan Mountains, Colorado and Bingham Canyon and Tintic, Utah, both.
Peru has produced some of the largest Enargite crystals, in a wide variety of locations. Originally Enargite was described as a new species from the San Francisco vein copper mines, Junin Department, Peru. The name derives from Greek έναργής (distinct), referring to the distinct cleavage thereof. The Jinguashi Mine, Ruifang District, New Taipei City, Taiwan, and the Furtei Mine, Medio Campidano, Sardinia, Italy are other important locations worldwide.
Enargite is similar to lazarevicite (named after M. Lazarevic), which contains the same chemical formula but has a cubic crystalline structure. The Bingham Canyon Mine, Salt Lake Co., Utah; and the Longfellow Mine, Red Mountain District, San Juan Co., Colorado have strong crystals as well.