Compounds of cobalt have proved useful throughout history, and it remains an important element to this day, with applications in chemical synthesis. The name is thought to derive from the German kobold, meaning 'goblin' or 'evil sprite'. The difficulty in isolating cobalt from its ore — and the release of arsenic oxide that often accompanied the smelting process — were both attributed to the work of evil spirits by the miners who were tormented by this element. Undoubtedly, cobalt's relative scarcity also played a part — it makes up only 29 ppm of the earth's crust and is the thirtieth most abundant element on earth; the second rarest transition metal after scandium.
- chemical synthesis