أكسيد النحاس (II).

Copper(II) oxide is used as pigments for coloring glass, ceramics, porcelain and artificial gems; in batteries and electrodes; in antifouling paints; in electroplating; in welding fluxes for bronze; in the production of rayons; for removal of sulfur from oils; in phosphor mixtures; for polishing optical glass; and as a catalyst. It also is used to prepare various copper compounds.Copper(II) oxide is found in nature as the minerals tenorite and paramelaconite. They differ in crystalline structure: tenorite exists as triclinic crystals while paramelaconite consists of tetrahedral cubic crystals.
Black monoclinic crystal or black to brown-black amorphous crystalline powder; Insoluble in water and alcohol; soluble in dilute acid, ammonium chloride, ammonium carbonate and potassium cyanide.