(Gr. osme, a smell) Discovered in 1803 by Tennant. Found in iridosmine and with platinum-bearing sands and ores. The powdered or spongy metal slowly gives off osmium tetroxide, a powerful oxidizing agent with a strong odor, and is highly toxic. Low concentrations cause lung congestion, skin and eye damage.The densest element known.
osmium tetroxide used to detect fingerprints, to stain tissue for electronmicroscopy, alloying for hardness, pen tips, instrument pivots, phonograph needles, electrical contacts