Cobalt is a transition metal first isolated by Swedish chemist George Brandt in 1735. Previously it has been used for centuries as a blue glaze for pottery. Persian’s used cobalt blue dating back to the 3rd millenium BC. The name cobalt is derived from the German ‘kobalt’ which means goblin used by the miners who found Cobalt ores. Georg Brandt found that cobalt was the blue colour in glass which had previously been identified as Bismuth. Cobalt is widely used in aircraft parts and alloys to prevent corrosion. It is also used in the production of batteries. The radioactive Cobalt-60 is used in the treatment of cancer. Cobalt is not found as a free element in nature it is found in mineral ores, most commonly those identified by the Assyrians who used them in painting. It is located in Group 9 and it has a melting point of 1495°c and a boiling point of 2927°c being a solid metal at room temperature.
Used in many hard alloys; for magnets, ceramics and special glasses. Remains hard up to 982°C. Radioactive cobalt-60 is used in cancer therapy.
Occurs in compounds with arsenic, oxygen and sulfur as in cobaltine (CoAsS) and linneite (Co3S4). Pure cobalt is obtained as a byproduct of refining nickel, copper and iron.