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[ir-i-doz-min, -dos-, ahy-ri-] /ˌɪr ɪˈdɒz mɪn, -ˈdɒs-, ˌaɪ rɪ-/
a native alloy of iridium and osmium, usually containing some rhodium, ruthenium, platinum, etc., used especially for the points of gold pens.
Also, iridosmium
[ir-i-doz-mee-uh m, -dos-, ahy-ri-] /ˌɪr ɪˈdɒz mi əm, -ˈdɒs-, ˌaɪ rɪ-/ (Show IPA)
Also called osmiridium.
1820-30; irid- + osm(ium) + -ine2 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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British Dictionary definitions for iridosmine


/ˌɪrɪˈdɒsmaɪn; ˌaɪrɪ-/
other names for osmiridium
Word Origin
C19: from irido- + osm(ium) + ine-²
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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Encyclopedia Article for iridosmine

mineral consisting of an alloy of iridium and a smaller proportion of osmium. It occurs in gold-bearing conglomerates, as at the Witwatersrand in South Africa, and in gold sands, as in California and Oregon, U.S. Because of their hardness and resistance to corrosion, both natural and synthetic iridosmine are used for tips of pen nibs, surgical needles, and sparking points in engines. Similar alloys composed of more osmium than iridium are called siserskite. Both iridosmine and siserskite crystallize in the hexagonal system. For detailed properties, see native element (table)

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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