Chemistry

Cobalt



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Atomic Symbol: Co
Atomic Number: 27
Atomic Weight: 58.9332
Atomic Category: Transition metals
Melting Point: 1495 degrees Celsius
Boiling Point: 2927 degrees Celsius
Appearance: Metallic with gray tinge

One of the oldest known transition metals, Cobalt has been around for centuries. Sculptures and jewelry from the ruins of Pompeii (destroyed 79 C.E.) and from both the Tang (618-907 C.E.) and Ming (1368-1644 C.E.) dynasties have been found with glazes created from cobalt. There have even been some ingots with cobalt glass found in wrecks dating from the time of the Minoans.

Even with being used in glasses, glazes, and ceramics early on, it wasn't until 1735 that cobalt was isolated by George Brandt. Previously it had been believed that it was the bismuth found with cobalt that was coloring glass blue, which was not the case. Brandt was able to prove that the blue was caused by cobalt, not bismuth. His initial discover helped pave the road for John Livingood and Glenn Seaborg's discovery of cobalt-60 in 1938. Cobalt-60 was then in turn used as a key element in nuclear weapons.

Cobalt, like many other transitional metals, is not found naturally by itself. It is usually found in the form of an ore that is mined and produced as a by-product of copper and nickel. The main ores that cobalt can be found in include erythrite, skutterdite, glaucodot, and cobaltite. While it is not found naturally, it does play an essential part for many living organisms as it not only improves the health of grazing animals, but is also a component of the vitamins cobalamin and B12.

While it is needed to help sustain life, cobalt at high levels shows similar mutagenic and carcinogenic properties as nickel. Cobalt can enter into a humans body through ingestion, inhalation, injection, or through the skin. Because of the last of these means of transportation, potters are the most at risk for cobalt poisoning due to the large usage of cobalt blue. However, studies have shown that cobalt poisoning is less dangerous than lead poisoning due to the fact that cobalt can be expelled from the body, unlike lead. While it poses less of a threat, those in certain industries should be aware of the possibility for cobalt poisoning.

Current uses of cobalt and its isotopes:
* Glazes
* Glass coloring
* Inks
* Paints
* Varnish
* Alloys (high speed steels, carbides, and diamond tools
* Magnets (recording media)
* Catalysts for petrol
* Drying agents for varnish and paint
* Lithium ion battery electrodes
* Steel-belted radial tires

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