: the oxide Cu2O that occurs naturally as cuprite and is obtained as red or yellow crystals or powder by oxidation of copper in a furnace or by electrolysis and that is used chiefly as a pigment (as in ceramics and in antifouling paints) and as a seed disinfectant and fungicide
called alsocopper(I) oxide, cuprous oxide, red copper oxide
b
: the monoxide CuO that occurs naturally as paramelaconite and tenorite, is obtained usually in black amorphous form by oxidizing copper, and is used chiefly in preparing cuprammonium solution, as a pigment in ceramics, as a catalyst for hydrogenations, and in chemical analysis
called alsoblack copper oxide, copper(II) oxide, cupric oxide
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