The densest substance known and the hardest of all platinum group metals, osmium has become a central material in many everyday and innovative items.

Having discovered platinum and palladium, William Hyde Wollaston handed over the remaining residues of ore to his commercial partner Smithson Tennant, a fellow Cambridge graduate with whom he had forged a partnership in 1800.
In 1804, Tennant isolated osmium (and iridium) from the residues and, due to the distinctive chlorine-like odour of its oxide, named it after the Greek for smell, "osme".

Originally, it was osmium's density and hardness that led to its widespread use - in everyday objects such as fountain pen nibs, styluses, electrical contacts and other tools where frictional erosion is likely to occur. By 1906, it was used in the filaments for incandescent lighting and is from where the company Osram derives it name.
In metal form, osmium's brittleness and hardness made it extremely difficult to work with and it is usually produced as a powder. This powder emits osmium tetroxide which is used in the detection of fingerprints and as a forensic stain for DNA samples.

Osmium occurs in a natural alloy with iridium called iridosule, in the platinum-bearing river sands of the Urals and North and South America, and as a by-product of nickel mining in Ontario's copper-nickel sulfide region, Sudbury.