(Gr. osme, a smell) Discovered in 1803 by Tennant in the residue left when crudeplatinum is dissolved by aqua regia.

Osmium occurs in iridosule and in platinum-bearing river sands of the Urals, NorthAmerica, and South America. It is also found in the nickel-bearing ores of Sudbury,Ontario region along with other platinum metals. While the quantity of platinum metals inthese ores is very small, the large tonnages of nickel ores processed make commercialrecovery possible.