Osmium (Os) sits at number 76 on the periodic table in group 8 and the 6th period. A heavy blue-grey metal, osmium atoms weigh out at 190.23.
In 1803, a scientist by the name of Smithson Tennant discovered osmium (and iridium) in dark residue left behind from crude platinum being dissolved in a mixture of hydrochloric and nitric acid called aqua regia.
Osmium is a largely useless metal, being too brittle at all temperatures to be used on it's own for anything. It's brittle nature notwithstanding, osmium is used in as an alloy with other platinum group metals in fountain pen tips, instrument pivots, and electrical contacts.
Osmium is a useless element in biology as many of it's isotopes are distinctly harmful in any amount to the eyes, lungs, and skin.
Where is it found?
The easiest way to extricate osmium for our purposes is from the ore iridosmium, a naturally occurring alloy of iridium and osmium.