Cobalt has been used to colour pottery and glass for at least 2600 years, as evidenced by cobalt-containing glazes that having been found in Ancient Egyptian tombs. Chinese pottery from the Tang (600–900 AD) and Ming dynasties (1350–1650 AD) also contained blue colours made from cobalt-containing minerals.
Cobalt has increasingly been used in specialist applications, where it is difficult to substitute with alternative materials. In some applications, such as in medical diagnostics, pharmaceuticals and fermentation processes (for example, bio-mass), cobalt is essential. Demand for cobalt has now moved away from the traditional metal applications (superalloys, medical prosthetic alloys, hard metals, diamond tools, magnets) and towards chemical applications mainly as a result of the large increase in demand for rechargeable batteries.