Enargite

Enargite is a sulfosalt mineral that is an import ore of copper. Crystals are sometimes coated with a thin layer of Pyrite crystals, giving it a yellow appearance. Enargite is dimorphous with the mineral Luzonite, which forms in tetragonal crystals. Luzonite and Enargite sometimes form together in single altering crystals with different symmetry and cleavage habits.

Enargite is named for the Greek word enargos, meaning "distinct, in reference to its distinctive perfect cleavage.

Peru has produced some of the largest Enargite crystals, in a wide range of different localities. These include the Quiruvilca Mine, La Libertad Department; the Julcani Mine, Huancavelica Department; Casapalca, Lima Department; and the Morococha District, Junín Department. Other important worldwide localities include the Jinguashi Mine, Ruifang District, New Taipei City, Taiwan; and the Furtei Mine, Medio Campidano, Sardinia, Italy.

In the U.S., the premier locality for Enargite is the Butte District, Silver Bow Co., Montana, especially at the Leonard Mine and the East Colusa Mine. Good crystals have also from the Bingham Canyon Mine, Salt Lake Co., Utah; and from the Longfellow Mine, Red Mountain District, San Juan Co., Colorado.