cobalt

[ koh-bawlt ]

noun

1. a silver-white metallic element with a faint pinkish tinge, occurring in compounds whose silicates afford important blue coloring substances for ceramics. : Co; : 58.933; : 27; : 8.9 at 20°C.

cobalt

/ ˈkəʊbɔːlt /

noun

1. 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

cobalt

/ kō′bôlt′ /

1. 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.
2. See Periodic Table

Word History and Origins

Origin of cobalt¹

1675–85; < German Kobalt, variant of Kobold kobold

Word History and Origins

Origin of cobalt¹

C17: German Kobalt, from Middle High German kobolt goblin; from the miners' belief that malicious goblins placed it in the silver ore

Example Sentences

While opening more facilities in California would help, the program uses cobalt to produce high-energy radiation to sterilize the bugs — which is expensive and requires the lab to take extensive safety and security measures.

From Los Angeles Times

Instead of using cobalt or other radioactive materials, Wilson’s team uses an X-ray machine to irradiate the pests.

From Los Angeles Times

Today’s battery technology — necessary for electric vehicles and energy storage — relies on minerals including cobalt, magnesium, nickel and graphite.

From Los Angeles Times

Of course, in the fashion world, an item of clothing can't just be blue, so Laws says he thinks cornflower and cobalt blue will make a particular appearance across shows.

From BBC

At New York Fashion week, coloured mascara was all the rage and the cobalt blue mascara was a particular stand out at LaQuan Smith's catwalk.

From BBC

Related Words

• blue-green