Cuprous sulfide occurs in the form of black powder or lumps and is found as the mineral chalcocite. Large quantities of the compound are obtained by heating cupric sulfide (CuS) in a stream ofhydrogen. Cuprous sulfide is insoluble in water but soluble in ammonium hydroxide and nitric acid. Its applications include use in solar cells, luminous paints, electrodes, and certain varieties of solidlubricants.
