cobalt

Hard, lustrous, grey, metallic element, atomic number 27, relative atomic mass 58.933. It is found in various ores and occasionally as a free metal, sometimes in metallic meteorite fragments. It is used in the preparation of magnetic, wear-resistant, and high-strength alloys; its compounds are used in inks, paints, and varnishes.

The isotope Co-60 is radioactive (half-life 5.3 years) and is produced in large amounts for use as a source of gamma rays in industrial radiography, research, and cancer therapy. Cobalt was named in 1730 by Swedish chemist Georg Brandt (1694-1768); the name derives from the fact that miners considered its ore malevolent because it interfered with copper production.

Cobalt

Town in Timiskaming District, southeastern Ontario, Canada, on the western side of Lake Timiskaming, 113 km/70 mi north-northwest of North Bay and 411 km/255 mi north of Toronto; population (1991) 1,500. The site of a strike in 1903 that revealed one of the world's richest silver deposits, it developed as a boomtime service centre; the cobalt and other minerals found in the ore began to be exploited as well.

This was one of the first important mineral strikes in Canada, giving impetus to further exploration of the Canadian Shield.