iridium
/ɪˈrɪdɪəm
/ /ʌɪˈrɪdɪəm/noun [mass noun]
The chemical element of atomic number 77, a hard, dense silvery-white metal. (Symbol: Ir) 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.
Origin
Early 19th century: modern Latin, from Latin iris, irid- 'rainbow' (so named because it forms compounds of various colours).