Osmium (Os)

Osmium is a hard, brittle, bluish-white transition metal in the platinum group; it is the densest naturally occurring element.

Core Principles & Analysis

• Smithson Tennant discovered osmium in 1803 in the acid-insoluble residue of platinum ore, naming it from the Greek for smell after its pungent oxide.
• At 22.59 grams per cubic centimeter it is the densest naturally occurring element.
• Osmium alloys tip fountain pen nibs and instrument pivots, and osmium tetroxide stains specimens for electron microscopy and reveals fingerprints.

Specifications & Metrics

• NUM: 76
• SYMBOL: Os
• CATEGORY: Transition Metal