iridium
n. uncountablen. a very hard and heavy metal that is almost impossible to melt. It is one of the rarest elements on Earth and is often used in special tools and jewelry.
n. a hard, silvery-white, corrosion-resistant transition metal of the platinum group. It is the most corrosion-resistant and the second-densest element in the periodic table.
The scientist used a tiny amount of iridium to make the pen tip.
Because of its extreme durability, iridium is often alloyed with platinum to create spark plugs for high-performance engines.
The geological layer rich in iridium found at the Cretaceous-Paleogene boundary provides strong evidence for the impact hypothesis regarding the extinction of the dinosaurs.
From international scientific vocabulary, from the New Latin.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Last updated May 28, 2026