osmium [Os]

Introduction

From the Greek osme meaning smell. Discovered in 1803 by the English chemist Smithson Tennant in the residue obtained after dissolving crude platinum.

Occurrence

• occurs in iridosule & platinum-containing river sands

Characteristics

• a hard, brittle blue-gray or blue-black lustrous metal element of the platinum group
• high melting point
• heaviest metal known
• lustrous
• metal is not toxic, but volatile oxide (OsO4) is
  • OsO4 slowly released from powdered osmium
  • OsO4 has a strong smell

Uses

• catalyst
• alloys
• OsO4 is used as a fixitive for electron microscopy

More general terms

• chemical element
• metal

Additional terms

• periodic table

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=23937