Cobalt

How to spell cobalt

6 letters · 2 syllables

How to pronounce cobalt

Say the part in capitals loudest.

What does cobalt mean?

1. nounA hard, silvery-grey metallic chemical element (symbol Co) used in alloys, magnets and rechargeable batteries.
2. nounA deep, vivid blue, named after the pigment produced from cobalt compounds.

Cobalt in a sentence

• The new battery packs rely heavily on cobalt mined overseas.

• She painted the front door a striking cobalt to stand out on the street.

• Engineers chose a cobalt alloy because it keeps its strength at high temperatures.

• The dinner plates were glazed in a rich cobalt that caught the light.

Where does cobalt come from?

Language of origin: Germanic

Cobalt comes from the German word Kobalt, an alteration of Kobold, which meant a mischievous goblin or household sprite. Medieval German silver miners gave the name to a troublesome bluish ore that yielded no useful metal and gave off poisonous, arsenic-laden fumes when smelted, so they blamed it on these underground goblins. The Swedish chemist Georg Brandt isolated the metal from that ore around 1735 and kept the folkloric name, and English adopted the word in the mid-eighteenth century. The same Germanic root for a goblin or spirit also lies behind the English word 'kobold' used in fantasy and gaming. The pure metal turned out to be valuable after all, and its compounds produce the famous deep blue used in glass and ceramics, which is why the word now names both a metal and a colour. The unexpected single 'b' and the '-alt' ending trip people who expect a Latinate spelling.

How the word is built

• cobalt (from German Kobold: goblin) treated as a single root, no separable prefix or suffix