Word origin: COBALT Deep blue

Cobalt is a dangerous element. Not in itself, but because of its sneaky habit of combining with arsenic and releasing a deadly gas when heated.

17th century miners were well aware of the hazards of cobalt. They would routinely heat rock in order to make the precious underground substances they were mining easier to extract. They realised that when veins of a mysterious blue mineral were present, this heating process would sometimes cause a toxic vapour to fill the mine. The vapour could cause serious long-term health problems. It could even kill.

The reputation of this unknown blue substance spread. It became known as ‘kobold’ – a German word meaning ‘evil goblin’. It looked a bit like copper, but bluer, and it was a whole lot more deadly.

It wasn’t until 1735 that a scientist called Georg Brandt examined the blue rock with state-of-the-art equipment and realised that he’d discovered an entirely new element. By this time, the brighter side of ‘kobald’ had been discovered and it was highly sought after to add a vivid blue stain to ceramics, paint and glass.

Georg didn’t want to name his new discovery after an evil goblin. So he altered the word a little and cobalt was born. In everyday use, the word is now most often used to describe the bright blue pigment that signified death for people working in mines hundreds of years ago.

Posted in Etymology