In 1735 Georg Brandt (1694-1768) identified some properties of cobalt. Antoine Lavoisier (1743-1794) in his Traité Élémentaire de Chimie (Elementary Treatise of Chemistry, 1789) included a list of elements, or substances that could not be broken down further, which included cobalt.
Cobalt is a strategic metal with very important applications, including those requiring heat-resistant materials such as jet engines. The major source of cobalt is as a by-product of copper refining although it can also be obtained as a by-product of nickel and lead.
Cobalt(III) complexes display a range of colours including the pigment cobalt blue:
- [CoF6]3- - Green
- [Co(NH3)5Cl]2+ - Violet
- [Co(H2O)6]3+ - Blue
- [Co(NH3)5(H2O]3+ - Red
- [Co(NH3)6]3+ - Yellow-orange
- [Co(CN6]3- - Tail of absorption band in visible spectrum is yellow
To create coloured glass, required in the stained glass windows of Chartres Cathedral in France, metal oxide powders were added to the melted glass, their atoms bonding into the silicon/oxygen glass lattices: blue colours were provided by cobalt.