The chemical element of atomic number 77, a hard, dense silvery-white metal.
Iridium is a member of the transition series and is one of the densest metals. Iridium–platinum alloys are hard and corrosion-resistant and are used in jewellery and for electrical contacts‘Jewellery made of platinum, iridium and palladium gleamed majestically, now and then emitting flashes of brilliant light from the studded diamonds.’
- ‘The new electrochemical system is based on a magnesium anode, a seawater/catholyte electrolyte and an electrocatalyst of palladium and iridium catalyzed on carbon paper.’
- ‘The earth's crust is depleted in iridium and other platinum group elements, while meteorites are enriched in them.’
- ‘Previously, it was thought that any asteroid or comet collision would leave strong evidence of the element iridium, the signal found in the sedimentary layer from the time of the dinosaur extinction.’
- ‘They found the rare element iridium in the thin clay layer that caps the rocks of the Cretaceous era.’
Early 19th century modern Latin, from Latin iris, irid- ‘rainbow’ (so named because it forms compounds of various colours).