Cobalt is a transition metal which has the symbol Co and atomic number 27. It is a hard, lustrous, silver-gray metal that takes a high polish, resists corrosion, and has a high melting point. The name of the element comes from kobold, a goblin of German folklore.

Cobalt is used in many different alloys and compounds. The most popular being blue pigments for glass and ceramics called cobalt blue glass or cobalt blue glaze, which yields brilliant shades of blue on surfaces exposed to air.

Cobalt glass is also used as an electrical insulator in some types of batteries and in nuclear power plants. Cobalt compounds are used as a catalyst in the Haber Process to synthesize ammonia from nitrogen gas and hydrogen gas; they are also used in electrolytic refining of nickel, copper and other metals; as well as many other industrial processes.

Last modified: November 1, 2022