Specifications: Iridium Iridium is a chemical element that has the symbol Ir and atomic number 77. A dense, very hard, brittle, silvery-white transition metal of the platinum family, iridium is used in high-strength alloys that can withstand high temperatures and occurs in natural alloys with platinum or osmium. Iridium is notable for being the most corrosion-resistant element known and for its significance in the determination of the probable cause of the extinction, by a meteorite strike, of the dinosaurs. It is used in high-temperature apparatuses, electrical contacts, and as a hardening agent for platinum.
