Discovery date : 1739
Discovered by: Georg Brandt
Origin of the name: The name is derived from the German word 'kobald', meaning goblin.
Allotropes :
~>COBALT is a chemical element with symbol Co and atomic number 27. Like nickel, cobalt is found in the crust only in chemically combined form, save for small deposits found in alloys of natural meteoric iron.
| FACT BOX | |||
| Group | 9 | Melting point | 1495°C, 2723°F, 1768 K |
| Period | 4 | Boiling point | 2927°C, 5301°F, 3200 K |
| Block | d | Density (g cm−3) | 8.86 |
| Atomic number | 27 | Relative atomic mass | 58.933 |
| State at 20°C | Solid | Key isotopes | 59Co |
| Electron configuration | [Ar] 3d74s2 | CAS number | 7440-48-4 |
| ChemSpider ID | 94547 | ChemSpider is a free chemical structure database | |
The tomb of Pharaoh Tutankhamen, who ruled from 1361-1352 BC, contained a small glass object coloured deep blue with cobalt. Cobalt blue was known even earlier in China and was used for pottery glazes.
In 1730, chemist Georg Brandt of Stockholm became interested in a dark blue ore from some local copper workings and he eventually proved that it contained a hitherto unrecognised metal and he gave it the name by which its ore was cursed by miners in Germany, where it was sometimes mistaken for a silver ore. He published his results in 1739. For many years his claim to have uncovered a new metal was disputed by other chemists who said his new element was really a compound of iron and arsenic, but eventually it was recognised as an element in its own right.