Cobalt

related topics
{acid, form, water}
{@card@, make, design}
{disease, patient, cell}
{country, population, people}
{land, century, early}

Cobalt (play /ˈkbɒlt/ or /ˈkbɔːlt/)[3][4] is a chemical element with symbol Co and atomic number 27. It is found naturally only in chemically combined form. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.

Cobalt-based blue pigments have been used since ancient times for jewelry and paints, and to impart a distinctive blue tint to glass, but the color was later thought by alchemists to be due to the known metal bismuth. Miners had long used the name Kobold ore (German for goblin ore) for some of the blue-pigment producing minerals; they were named because they were poor in known metals, and gave poisonous arsenic-containing fumes upon smelting. In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), and this was ultimately named for the Kobold.

Today, some cobalt is produced specifically from various metallic-lustered ores, for example cobaltite (CoAsS), but the main source of the element is as a by-product of copper and nickel mining. The copper belt in the Democratic Republic of the Congo and Zambia yields most of the cobalt metal mined worldwide.

Full article ▸

related documents
Argon
Solid-state chemistry
Metal
Hydride
Bioleaching
Gadolinium
Smoke
Chemical vapor deposition
Rust
Tritium
Acid–base reaction
Miller-Urey experiment
Garnet
Halogen lamp
Disulfide bond
Ammonium nitrate
Clathrate hydrate
Agarose gel electrophoresis
Alpha helix
Fluorocarbon
Hydrocarbon
Molybdenum
Osmium tetroxide
Genetic code
Tin
Osmium
Sputtering
Ubiquitin
Cell (biology)
Materials science