Osmiridium
Appearance
Osmiridium, also called iridosmium, is a natural alloy of osmium and iridium, with traces of other platinum group metals, found naturally or man-made. Osmiridium contains about 50% iridium, while iridosmium contains about 70% iridium.[1]
Occurrence
Osmiridium is very rare, but it can be found in mines of other platinum group metals. It can be isolated by adding a piece to aqua regia, which has the ability to dissolve gold and platinum but not osmiridium. It occurs naturally as small, extremely hard, flat metallic grains with hexagonal crystal structure.
References
- ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.