Osmium is very hard and has the highest specific weight of all elements (twice as heavy as lead). It has the highest melting point in the platinum metals group. Its bulk modulus is the highest of all known metals and compounds; thereby it is even less compressible than diamond. Osmium is considered as chemically inert.
The technical applications for Osmium are relatively scarce due to its rarity and its complicated manufacturing process. It is partly used in catalysts for the synthesis of fine chemicals and organometallic compounds. Osmium is processed into crystals in the jewelry industry.