Cobalt is a rare heavy metal, which occurs mostly only in combination with other elements. It is usually extracted from copper and nickel ores. In the past, cobalt was mainly used to produce colour pigments. Today this element is used in batteries and as an alloying element, among other things.
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Cobalt ore was often wrongly identified as silver ore in the Middle Ages. However, cobalt ores usually also contain sulphur and arsenic compounds, which caused bad smells during smelting. The miners believed that cobolts had eaten the precious silver and left the cheap cobalt behind.
The chemist Georg Brandt discovered the metal in 1735 while experimenting with "kobold ore". Inspired by this medieval story, he named the metal cobalt.
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