It falls between platinum and osmium in group VIII of the periodic table . It is not certain whether osmium or iridium is the most dense element.
Iridium is found uncombined in nature as the metal and in combination with osmium and platinum.
It is obtained commercially from osmiridium, a byproduct of platinum production. The metal is used in pivot bearings and in scientific and other special equipment, such as surgical tools. It is also used in making chemical crucibles. Iridium is used principally in alloys. An alloy with osmium is used to make fountain-pen nibs.