Cobalt

Cobalt is a hard, lustrous metal, grey in color. It has been used as a coloring agent for centuries, without being noticed. Its discovery was relatively recent with respect to other elements, and credited for a Swedish chemist, Georg Brandt, in 1735.

Cobalt, like nickel, has a wide range of application areas. It is commonly used in petroleum and ceramic industries, also in super alloys used in jet turbines, high capacity batteries used in electronic appliances and coloring pigment used in dye industry. Furthermore, the radioisotope of cobalt (Co-60) is used in radiation therapy (radiotherapy).

Resource: Cobalt Development Institute http://www.thecdi.com/