To make osmium, you put platinum in aqua regia, then you take the residue it makes to get osmium.
Osmium is the densest element at 22.59 g/cm³.
When osmium is exposed to oxygen it can form osmium tetroxide which is poisonous.
Osmium has the 4th highest boiling point and melting point.
Osmium cost about $400 per troy ounce.
Osmium is only found at 0.05 parts per billion of earth