Discovered : 1735 by G. Brandt Isolated in Stockholm, Sweden Origin : The name is derived from the German ‘Kobald’, meaning goblin. Description : A lustrous, silvery metal with a blue cast. It can be magnetised like iron and so is used to make magnets, as well as in ceramics and paints. The radioactive isotope cobalt-60 is used in medical treatment and, in some countries, to irradiate food to preserve it. Cobalt is an essential element for humans since it is part of vitamin B12. The amount needed is very small and the body contains only about 1 milligramme (less than 1/30,000th of an ounce). Image : China blue.