chalcocite
Chal"co*cite, n. Etym: [Gr. (Min.) Defn: Native copper sulphide, called also copper glance, and vitreous copper; a mineral of a black color and metallic luster. [Formerly written chalcosine.]
Chal"co*cite, n. Etym: [Gr. (Min.) Defn: Native copper sulphide, called also copper glance, and vitreous copper; a mineral of a black color and metallic luster. [Formerly written chalcosine.]