Platinum
Native platinum and its iron alloys, found as tiny grains in chondrites and in iron meteorites.
Key facts
- Formula
- (Pt,Fe)
- Family
- Metals and alloys
- Crystal system
- Cubic
What it is
Platinum is a heavy, unreactive precious metal. In meteorites it is usually alloyed with iron and with the other platinum-group metals, which dissolve readily in iron–nickel metal. Most of Earth's platinum sank into its core, and much of what is mined may have been added later by meteorites.
Where it is found
Platinum-rich alloys occur in refractory metal nuggets in calcium-aluminium-rich inclusions, and as tiny grains in the metal of some chondrites and irons. Iron meteorites are rich in platinum-group metals overall, though spread through the metal rather than as visible grains.
How it is recognised
It is found with the scanning electron microscope as bright, metal-rich specks, and analysed with the microprobe.
Did you know?
Platinum was first recognised as a separate metal in the eighteenth century, from river sands in South America.
Some scientists have proposed mining metal-rich asteroids for platinum-group metals.