Definition of iridium
: a rare silver-white hard brittle very heavy metallic element — see element table
Recent Examples of iridium from the Web
Rhodium, iridium and ruthenium count among the precious metals that are more rare than gold, according to the U.K.’s Royal Mint.
Paleontologists tell us of five major extinctions, the last of which was brought to a head, in theory, by a mischievous asteroid that did in the dinosaurs and coated the world in a thin layer of iridium-rich sediment 66 million years ago.
Iridium provides communication services including satellite telephones through its network of satellites circling the Earth at an altitude of 485 miles.
The rock layer marking the end of the Cretaceous period was rich in iridium, a metal that is rare in Earth’s crust but more common in meteorites and asteroids.
With its standard-setting platinum-iridium meter bars and kilogram nuggets stored in safes, this institution worships accuracy.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'iridium'. Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
Origin and Etymology of iridium
New Latin, from Latin irid-, iris; from the colors produced by its dissolving in hydrochloric acid
First Known Use: 1804See Words from the same year
IRIDIUM Defined for Kids
Definition of iridium for Students
: a hard brittle heavy metallic chemical element
Seen and Heard
What made you want to look up iridium? Please tell us where you read or heard it (including the quote, if possible).