Definition of "iridium" [i•rid•i•um]

• A very 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 192.2; melting point 2,410°C; boiling point 4,130°C; specific gravity 22.42 (at 17°C); valence 3, 4. See Table at element. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

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