The word cobalt comes from the German Kobald which means goblin or evil spirit (cobalt is toxic).
Atomic Number: 27
Atomic Mass: 58.9332 u
Number of Protons/Electrons: 27
Number of Neutrons: 32
Boiling Point: 2870.0 °C (3143.15 K, 5198.0 °F)
Classification: Transition Metal
Crystal Structure: Hexagonal
Cobalt compounds have been used since ancient times to give a distinctive blue color to porcelain, glass, ceramics, inks, paints and varnishes.
It was found:
- in Ancient Egyptian sculptures
- in Persian jewelry from the third millennium BC
- in the Roman Empire, ruins of Pompeii (destroyed in 79 AD)
- in China dating from the Tang dynasty (618-907 AD)
The most common is the cobalt blue, but there are also ceruleum, new blue, smalt, cobalt yellow and cobalt green.
Cobalt around us
- in Universe 0.0003%
- in Sun 0.0004%
- in Meteorites 0.059%
- in Humans 2×10-6%
In addition to being used as a dye, cobalt is also important to nutrition being an essential part of vitamin B12.
Twenty-six isotopes of cobalt have been identified, from which the only stable one is cobalt-59. Cobalt-60 is an important radioisotope, used as a radioactive tracer and in the production of gamma rays.
Cobalt is a hard, lustrous, silver-gray metal and is used in the preparation of magnetic, high-strength alloys.