Iridium (Ir)

Iridium ([Xe]4f¹⁴5d⁷6s²) (CAS 7439-88-5) a precious metal, has an appearance similar to platinum in that it is white, but with a slightly yellowish tint. It is the most corrosion-resistant metal known, is very hard, brittle, and has a low ductility, making it difficult to machine, form, or work. Its principle use is as a hardening agent for platinum, though it is frequently found in crucibles and other high temperature devices.