Copper Carbonate – CuCO3 (m.p. 2100o F/1149o C) is the most common source for Copper Oxide and is used (2%-5%) as a colorant to produce greens, turquoise, and copper reds. It has a fine particle size that enhances the production Alkaline glazes: turquoise in oxidation, and copper red in reduction (also see Copper Oxide). It is volatile above cone 8.