Osmium

n. bluish-white metallic element of the platinum group that is often used in the manufacturing of pen tips and ball bearings

Osmium (IPA: ) is a chemical element that has the symbol Os and atomic number 76. A hard, brittle, blue-gray or blue-black transition metal in the platinum family, osmium is one of the densest natural elements and is used in some alloys with platinum and iridium. Osmium is found native as an alloy in platinum ore and its tetroxide has been used to stain tissues and in fingerprinting. Alloys of osmium are employed in fountain pen tips, electrical contacts and in other applications where extreme durability and hardness are needed.
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Noun
1. a hard brittle blue-gray or blue-black metallic element that is one of the platinum metals; the heaviest metal known
(synonym) Os, atomic number 76
(hypernym) metallic element, metal

n. Os, osmium, metallic chemical element of the platinum group

n. osmium, bluish-white metallic element of the platinum group that is often used in the manufacturing of pen tips and ball bearings