Osmium (Os)

One of the platinum group metals, osmium ([Xe]4f¹⁴5d⁶6s²) (CAS 7440-04-2) is bluish-white, lustrous, extremely hard, and brittle. Its properties make it ideal for combining with other platinum metals to produce very hard alloys. Osmium has the highest melting point and lowest vapor pressure of the platinum group and it is very difficult to fabricate. While osmium powder or sponge is affected by air at room temperature, the metal is relatively inert in ambient conditions.