cobalt

Meanings

1. 1noununcountablechemistry

   A hard, silvery-white metallic chemical element used in alloys and batteries.

   Grammar: Uncountable: no plural. Chemical symbol Co.

   Patterns

   • cobalt in batteries
   • a cobalt alloy

   Cobalt is essential for making rechargeable batteries.

   The alloy contains cobalt to increase its strength.

   Mining cobalt has environmental and social impacts.

2. 2noununcountable

   A deep blue pigment made from cobalt compounds, used in glass, ceramics, and paint.

   Grammar: Uncountable: no plural. Often used before another noun: cobalt blue.

   Patterns

   • cobalt blue
   • a shade of cobalt

   The artist mixed cobalt with white to create a lighter blue.

   The vase was decorated with a rich cobalt glaze.

   Cobalt has been used for centuries to color glass deep blue.

3. 3noununcountable

   A strong blue color, like the pigment made from cobalt.

   Grammar: Uncountable: no plural. Often used in the phrase 'cobalt blue'.

   Patterns

   • in cobalt
   • cobalt blue

   She wore a dress in vibrant cobalt.

   The sky was a brilliant cobalt at noon.

   The team's new uniforms are cobalt and white.

Common combinations

cobalt blue

The painter chose cobalt blue for the ocean.

cobalt mining

Cobalt mining is concentrated in a few countries.

cobalt alloy

The turbine blades are made from a cobalt alloy.

cobalt salt

Cobalt salts are used to produce blue pigments.

Synonyms and how they differ

cerulean

A lighter, sky-blue color; cobalt is deeper and more intense.

navy

A very dark blue; cobalt is brighter and more vivid.

Word family

cobaltic adjective

Relating to cobalt, especially in its higher oxidation state.

cobaltous adjective

Relating to cobalt in its lower oxidation state.

Commonly confused: cobalt or copper?

Practice

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