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

  • n. A bluish-white, hard metallic element, found in small amounts in osmiridium, nickel, and platinum ores. It is used as a platinum hardener and in making pen points, phonograph needles, and instrument pivots. Atomic number 76; atomic weight 190.2; melting point 3,000°C; boiling point 5,000°C; specific gravity 22.57; valence 2, 3, 4, 8. See Table at element.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. a heavy metallic chemical element (symbol Os) with an atomic number of 76

from the GNU version of the Collaborative International Dictionary of English

  • n. A rare metallic element of the platinum group with atomic number 76. It is found native as an alloy in platinum ore, and in iridosmine. It is a hard, infusible, bluish or grayish white metal, and the heaviest substance known. Its tetroxide is used in histological experiments to stain tissues. Symbol os. Atomic weight 190.2. Specific gravity 22.477.

from The Century Dictionary and Cyclopedia

  • n. Chemical symbol, Os; atomic weight, 191. One of the metals of the platina group.
  • n. This, the most refractory of the metals, has, though with difficulty, been completely fused into globules by means of the electric furnace.

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

  • n. a hard brittle blue-grey or blue-black metallic element that is one of the platinum metals; the heaviest metal known


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

From Greek osmē, smell (from the strong odor of osmium tetroxide).

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Ancient Greek ὀσμή ("smell") (because of the strong smell of its oxide) + -ium


  • I will go and personally sign out the osmium from the strategic metal and you can use it for your theses experiments.

    George F. Smoot - Autobiography

  • INTERNATIONAL CORRESPONDENT: Counterterrorism police have foiled an apparent plot to launch a chemical attack in Britain that according to U.S. and U.K. security sources who say the suspects had plans to lace a bomb with a chemical called osmium tetroxide.

    CNN Transcript Apr 6, 2004

  • The process removes sulfur present in the ore as sulfur dioxide and, at the same time, releases osmium, which is abundant in the ore.

    GEN News Highlights

  • We conclude that not all highly siderophile elements were affected by core formation in the same way, and that the abundances of elements such as osmium and iridium require the addition of a late veneer.

    Naturejobs - All Jobs

  • She took a deep breath to force herself to calm down, and then checked the microscopic particle of osmium on the transfer platform.

    365 tomorrows » 2010 » May : A New Free Flash Fiction SciFi Story Every Day

  • Company president Luke Nosek, a cofounder of PayPal, bragged that Halcyon would ultimately sequence complete human genomes in ten minutes for $100 or less, and at an astonishing 99.9999 percent accuracy.3 The scientific cofounders, the Andregg brothers, stretched out single strands of DNA on a sheet of carbon, attaching platinum atoms to the G bases and osmium to the T bases.

    The $1,000 Genome

  • We had determined that the most effective target for turning a positive kaon beam into a neutral kaon beam would be made of osmium.

    George F. Smoot - Autobiography

  • By early morning, we had a significant pile of silver colored aluminum chips and dust similar color to osmium.

    George F. Smoot - Autobiography

  • I told him how it did not fit and how we had to saw and file on the osmium all night.

    George F. Smoot - Autobiography

  • When he came in enthusiastically greeting us, I wiped my brow as I finished screwing back together the target box and complained how hard osmium was to work with.

    George F. Smoot - Autobiography


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  • Os.

    December 16, 2007