Definitions

from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun A very dense, hard, and brittle, exceptionally corrosion-resistant, whitish-yellow metallic element occurring in platinum ores and used principally to harden platinum and in high-temperature materials, electrical contacts, and wear-resistant bearings. Atomic number 77; atomic weight 192.22; melting point 2,446°C; boiling point 4,428°C; specific gravity 22.562 (at 20°C); valence 2, 3, 4, 6. cross-reference: Periodic Table.

from The Century Dictionary.

  • noun Chemical symbol, Ir; atomic weight, 193. A metal of silver-white color, belonging to the platinum family, and, so far as known, always present in native platinum.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Chem.) A rare metallic element of atomic number 77, of the same group as platinum, which it much resembles, being silver-white and indifferent to most corrosive agents, but harder, more brittle, and with a higher melting temperature (2410° C, versus platinum 1772° C). With the exception of osmium, it is the heaviest substance known, its specific gravity being 22.4. Symbol Ir. Atomic weight 192.22.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun A metallic chemical element (symbol Ir) with an atomic number of 77.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium

Etymologies

from The American Heritage® Dictionary of the English Language, 4th Edition

[From Latin īris, īrid-, rainbow (from the colors produced by dissolving it in hydrochloric acid); see irido– + –ium.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Ancient Greek ἶρις ("rainbow") (because of the bright colour of many of iridium's salts).

Examples

  • The more common thicker photovoltaics contain iridium and other rare and expensive materials.

    BRITISH TEAM DEVELOPS THIN SOLAR PHOTOVOLTAICS | Inhabitat

  • Maganda ba? mga sir, ito po ang cdi na gamit ko ngyn. .naka iridium nako at blue thunder ignition coil. .pero bkit parang wala akong na-feel na dagdag power or speed?

    Motorcycle Philippines

  • Ionizing radiation can also come from industrially produced radioactive materials (such as iridium-192); nuclear medicine (such as thyroid cancertreatment with iodine-131 and thyroid scans using iodine-125, or bone scans using technetium-99m); biological and medical research using carbon-14, tritium, and phosphorus-32; the nuclear fuel cycle (producing fission products such as cesium-137 and activation products such as cobalt-60); and production and testing of nuclear weapons.

    Public Health Statement for Ionizing Radiation

  • "They indicate there was an extra-terrestrial event on Earth 12,900 years ago .." impact material such as iridium and magnetic microspherules - as well as an NY Times report.

    Slugger O'Toole

  • "They indicate there was an extra-terrestrial event on Earth 12,900 years ago .." impact material such as iridium and magnetic microspherules - as well as an NY Times report.

    Slugger O'Toole

  • Scientists last year reported the discovery of five types of nano-diamonds along with impact material such as iridium and magnetic microspherules in the Younger Dryas impact layer,

    The Unreasonable Man

  • "They indicate there was an extra-terrestrial event on Earth 12,900 years ago .." impact material such as iridium and magnetic microspherules - as well as an NY Times report.

    Slugger O'Toole

  • "They indicate there was an extra-terrestrial event on Earth 12,900 years ago .." impact material such as iridium and magnetic microspherules - as well as an NY Times report.

    Slugger O'Toole

  • "They indicate there was an extra-terrestrial event on Earth 12,900 years ago .." impact material such as iridium and magnetic microspherules - as well as an NY Times report.

    Slugger O'Toole

  • "They indicate there was an extra-terrestrial event on Earth 12,900 years ago .." impact material such as iridium and magnetic microspherules - as well as an NY Times report.

    Slugger O'Toole

Comments

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  • Ir.

    December 16, 2007