Ir - Iridium
(L. iris, rainbow) Tennant discovered iridium in 1803 in the residue left when crudeplatinum is dissolved by aqua regia. The name iridium is appropriate because itssalts are highly colored.
Iridium occurs uncombined in nature with platinum and other metals of this family inalluvial deposits. It is recovered as a by-product from the nickel mining industry.