Iridosmine

Name:
Iridosmine
Detailed information:

Chemistry name:	osmiridium
Properties:
Tin-white to light steel gray in color; streak, same; metallic luster. D l8.8–21.12, Mohs hardness 6–7. Composition is variable ranging from 10.0–77.2% iridium, 17.2–80.0% osmium, 0–10.1% platinum, 0–17.2% rhenium, 0–8.9% ruthenium, 0–1.5% iron, 0.0.9% copper, trace, palladium. Unattacked by aqua regia.
Occurrence:
Alaska, South Africa.
Use:
Fountain-pen point tips, surgical needles, watch pivots, compass bearings, hardening platinum (standard weights, jewelry), source of iridium and osmium.