irid·​i·​um | \ i-ˈri-dē-əm How to pronounce iridium (audio) \

Definition of iridium

: a rare silver-white hard brittle very heavy metallic element — see Chemical Elements Table

Examples of iridium in a Sentence

Recent Examples on the Web Melted pottery shards, which melt at temperatures above 1500C. Mudbricks, that melt above 1400C. A host of melted elements and minerals, such as platinum, iridium, and quartz. Elizabeth Fernandez, Forbes, 23 Sep. 2021 In Colorado, for instance, 27 buildings house scary-sounding elements such as cesium 137, cobalt 60, americium 241 and iridium 192. Sarah Scoles, Scientific American, 11 Mar. 2022 What's more, the fish were found just beneath a layer of rock known as the iridium anomaly, which is rich in a dense element common in asteroids and rare on Earth. Katie Hunt, CNN, 23 Feb. 2022 In addition to iridium, the crater section showed elevated levels of other elements associated with asteroid material. David Bressan, Forbes, 24 Feb. 2021 Here’s the research setup: A woman speaks Dutch into a microphone, while 11 tiny needles made of platinum and iridium record her brain waves. Adam Rogers, Wired, 9 Nov. 2021 In addition, the surfaces of the pottery and meltglass are speckled with tiny melted metallic grains, including iridium with a melting point of 4,435 F (2,466 C), platinum that melts at 3,215 F (1,768 C) and zirconium silicate at 2,800 F (1,540 C). Christopher R. Moore, The Conversation, 20 Sep. 2021 The core helped to precisely date the sediments containing iridium-rich dust. David Bressan, Forbes, 24 Feb. 2021 The Census Bureau’s count for other precious metals includes silver, platinum, palladium and more obscure sources such as ruthenium and iridium. Dian Zhang, USA TODAY, 3 Mar. 2021 See More

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.

First Known Use of iridium

1804, in the meaning defined above

History and Etymology for iridium

Greek īrid-, îris "rainbow, iridescent halo around the moon, a flame, etc., iris entry 1" + New Latin -ium -ium; from the colors produced by dissolving it in hydrochloric acid

Note: The word iridium was introduced by the English chemist Smithson Tennant (1761-1815) in Philosophical Transactions of the Royal Society, 1804, Part II, p. 414: "As it is necessary to give some name to bodies which have not been known before, and most convenient to indicate by it some characteristic property, I should incline to call this metal Iridium, from the striking variety of colours which it gives, while dissolving in marine acid." See also osmium.

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The first known use of iridium was in 1804

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Cite this Entry

“Iridium.” Dictionary, Merriam-Webster, Accessed 14 Aug. 2022.

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More Definitions for iridium


irid·​i·​um | \ i-ˈri-dē-əm How to pronounce iridium (audio) \

Kids Definition of iridium

: a hard brittle heavy metallic chemical element


irid·​i·​um | \ ir-ˈid-ē-əm How to pronounce iridium (audio) \

Medical Definition of iridium

: a silver-white hard brittle very heavy metallic element of the platinum group used especially in hardening platinum for alloys (as for surgical instruments) symbol Ir — see Chemical Elements Table

More from Merriam-Webster on iridium

Nglish: Translation of iridium for Spanish Speakers Encyclopedia article about iridium


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