osmiridium
/ˌɑzmɪˈrɪdiəm/
noun
- A hard, dense natural alloy of osmium and iridium, used for pen nibs and instrument bearings.
- Osmiridium is valued for its resistance to wear in scientific instruments.
- Miners occasionally find osmiridium in platinum deposits.
- The vintage fountain pen had a tip made of osmiridium for durability.