[koh-bawlt] /ˈkoʊ bɔlt/
a silver-white metallic element with a faint pinkish tinge, occurring in compounds whose silicates afford important blue coloring substances for ceramics. Symbol: Co; atomic weight: 58.933; atomic number: 27; specific gravity: 8.9 at 20°C.
a brittle hard silvery-white element that is a ferromagnetic metal: occurs principally in cobaltite and smaltite and is widely used in alloys. The radioisotope cobalt-60, with a half-life of 5.3 years, is used in radiotherapy and as a tracer. Symbol: Co; atomic no: 27; atomic wt: 58.93320; valency: 2 or 3; relative density: 8.9; melting pt: 1495°C; boiling pt: 2928°C
1680s, from German kobold “household goblin,” Harz Mountains silver miners’ term for rock laced with arsenic and sulfur (so called because it degraded the ore and made the miners ill), from Middle High German kobe “hut, shed” + *holt “goblin,” from hold “gracious, friendly,” a euphemistic word for a troublesome being. The metallic element was extracted from this rock. It was known to Paracelsus, but discovery is usually credited to the Swede George Brandt (1733), who gave it the name. Extended to a blue color 1835 (a mineral containing it had been used as a blue coloring for glass since 16c.). Cf. nickel.
cobalt co·balt (kō’bôlt’)
A metallic element, used chiefly for magnetic and high-temperature alloys and in the form of its salts for blue glass and ceramic pigments. Atomic number 27; atomic weight 58.9332; melting point 1,495°C; boiling point 2,930°C; specific gravity 8.9; valence 2, 3.
A silvery-white, hard, brittle metallic element that occurs widely in metal ores. It is used to make magnetic alloys, heat-resistant alloys, and blue pigment for ceramics and glass. Atomic number 27; atomic weight 58.9332; melting point 1,495°C; boiling point 2,900°C; specific gravity 8.9; valence 2, 3. See Periodic Table.
noun, Chemistry. 1. a radioactive isotope of cobalt having a mass number of 60 and a half-life of 5.2 years, used chiefly in radiotherapy. cobalt 60 [(koh-bawlt)] A radioactive isotope produced when neutrons bombard atoms of the element cobalt. Note: Cobalt 60 is a common substance used in radiation therapy for cancer.
[koh-bawlt-am-een, -uh-meen] /ˌkoʊ bɔltˈæm in, -əˈmin/ noun 1. any of the various complex derivatives of cobalt containing one or more molecules of ammonia bonded to the cobalt.
noun, Mineralogy. 1. (def 1) noun 1. another name for erythrite (sense 1)
noun 1. a deep blue to a strong greenish-blue color. 2. any of a number of pigments containing an oxide of cobalt. noun 1. Also called Thénard’s blue. any greenish-blue pigment containing cobalt aluminate, usually made by heating cobaltous sulphate, aluminium oxide, and phosphoric acid together 2.