covellite, a sulfide mineral that is a copper ore, cupric sulfide (CuS). It typically occurs as an alteration product of other copper sulfide minerals (chalcopyrites, chalcocite, and bornite) present in the same deposits, as at Leogang, Austria; Kawau Island, N.Z.; and Butte, Mont., U.S. Covellite forms crystals that belong to the hexagonal system. For detailed physical properties, see sulfide mineral (table).