What in the Word?! Mining the roots of ‘cobalt’
Cobalt is quite the mischievous word. It immediately conjures up the striking blue of fine china, jewellery, and art, like the swirls of Starry Night or swells of the Great Wave Off Kanagawa. But etymologically, cobalt conjures up something, well, not quite so fine: nasty little German goblins.
Ancient pigment, modern element
Cobalt has been used for colouring since antiquity. Ancient Egyptians, for instance, were painting with cobalt-derived pigments as far back as 2500 BCE. But it wasn’t until the 1730s that anyone isolated and purified cobalt, as it naturally occurs in nickel and copper-based ores. That was Swedish chemist Georg Brandt, who is credited with its discovery as a distinct chemical element. (Cobalt was earlier known to the great Swiss physician and alchemist Paracelsus in the 16th century.)
Brandt wanted to know what was giving certain ores a bluish tint. Previously, people had suspected it was the element bismuth, but he demonstrated that the mystery metal was something else. Writing in Latin, Brandt referred to the metal as regulus cobalti, or ‘regulus of cobalt’. Regulus is an old chemistry term for the metallic form of a substance obtained by smelting or reduction. As for cobalt, Brandt adapted a nickname used by German miners: Kobold, a ‘demon’ or ‘goblin’.
What could be so diabolical about cobalt?
Cobalt has long caused a lot of trouble for miners deep down in the silver-rich veins of the northern Germany. Its ore, especially when combined with arsenic and sulphur, can look a lot like silver ore. Miners would extract it from the earth only to discover it yielded no precious metal when they smelted it. What’s more, the exposure to arsenic vapours during processing could prove harmful, if not deadly.
So, these early miners blamed their subterranean pains on the Kobolds. In German folklore, Kobolds are fickle sprites – much like pucks – that dwell in people’s houses, ships, caves, or mines. Treat them well, and they might give you a hand with small jobs and chores. But cross them, and they might steal from you, among other forms of mischief. (Cornish folklore features a similar tradition with its mine-haunting knockers.)
Ekkehard Schwab, a research director at German chemical-producing giant BASF, offers one tale of Kobold mine-meddling:
At the end of the 16th century, the yield of the silver mines in the German region of Saxony declined from year to year. Kobold was blamed for stealing the silver and leaving behind worthless rock. Around this time, a young man skilled in the art of smelting arrived in Schneeberg, one of the main mining towns, and started to experiment with the strange dead rock that was assumed to be silver ore. Because he often did this at night and behind closed doors, he aroused the suspicions of the townspeople. They were just about to arrest and sentence him as a wizard when he found a way to prepare a brilliant blue pigment. The people of Schneeberg quickly realized that although the young man had not found silver, he had discovered a valuable new material – cobalt blue, which is still one of the technical uses for cobalt.
Compound chemical, compound word
The brilliant pigment of cobalt blue is obtained from cobalt aluminate, a compound of cobalt, oxygen, and aluminum. But what about the German word Kobold?
Etymologists like Walter Skeat and Ernest Klein have supposed Kobold – this German word for ‘goblin’ – is itself related to that very word goblin, whose ultimate root is the ancient Greek kobalos, ‘rogue’ or ‘knave’.
In fact, some of the earliest evidence the Oxford English Dictionary finds for Kobold alludes to mining and kobalos. In his 1638 Hierarchy of the Blessed Angels, English playwright Thomas Heywood writes: ‘The Parts Septentrionall are with these Sp’ryts Much haunted… About the places where they dig for Oare. The Greekes and Germans call them Cobali’. (Septentrional is an old, obscure word meaning ‘northern’.) Heywood elsewhere called them Kibaldi.
Others, as we see in Robert Barnhart’s etymological dictionary, have mined a different vein. He breaks down Kobold into the German roots Kobe, a ‘hut’ or ‘shed’ and hold, ‘gracious’ or friendly’. Barnhart explains the counterintuitive hold as ‘from the superstitious practice of referring to evil beings by complimentary names to avoid their wrath’.
Some German philologists – notably Rudolf Hildebrand in the Grimm brother’s landmark Deutsches Wörterbuch, the OED of the German language – also root Kobold in Kobe. But for the second component, he speculates walten, ‘to rule over’, making a Kobold a kind of ‘ruler of the house’ and keeping with the home-inhabiting species of the fabled being.
An expanding palette
Whatever Kobold’s deeper origins, the mythical mining moniker stuck for the troublesome metal – and spread. The OED first finds cobalt in English some 50 years after Heywood’s Cobali, in Englishman John Pettus’s 1683 metallurgic treatise, Fleta Minor: ‘Concerning the Cobolt oars, there are many sorts of them’. (As a name for the element itself, cobalt is attested as early as 1863.)
And indeed there are many sorts – word-wise, too. In the OED, cobalt comes in a veritable rainbow, not just its distinctive blue. There’s grey cobalt and red cobalt. There’s tin-white cobalt and silver-white cobalt. There’s cobalt violet, cobalt yellow and the lovely cobalt ultramarine.
And just as many cobalt colours are cobalt’s uses: magnets, jet turbines, electroplating. Cobalt is even used for cancer treatment. Here, it comes in the form of the radioactive isotope cobalt-60, stored in a container called a cobalt bomb. Cobalt, no doubt, has come a long way from its colourful origins.