A tough, lustrous, nickel-white or silvery-gray, metallic element. Symbol, Co. Occurs in the minerals cobaltite, smaltite, and erythrite; often associated with nickel, silver, lead, copper, and iron ores, from which it is most frequently obtained as a byproduct. Its alloys have unusual magnetic strength and are used for high-speed, heavy-duty, hightemperature cutting tools, and for dies, in jet turbines and gas turbine generators. Its salts are used in porcelain, glass, pottery, tiles, and enamels to produce brilliant blue colors.