Vanadium

Vanadium was first encountered in 1801 by the Spanish-Mexican mineralogist Andres Manuel del Rio, who believed he had found a new metal but was persuaded he had merely seen impure chromium and withdrew his claim. It was rediscovered in 1830 by the Swedish chemist Nils Gabriel Sefstrom, and isolated later by Henry Roscoe. Vanadium is a hard, silvery transition metal chiefly valued for the strength and resilience it lends to steel. Small additions of vanadium produce the tough vanadium steels used in tools, springs and structural parts, while vanadium compounds serve as industrial catalysts and are being developed for the large flow batteries proposed to store energy from wind and solar power.

Del Rio first called his discovery panchromium, for the many colours its salts displayed, and then renamed it erythronium, before French chemists persuaded him he had merely mistaken impure chromium and he withdrew the claim, a retraction he reportedly regretted for the rest of his life once Sefstrom's independent rediscovery three decades later proved him right all along. Henry Ford was an early and enthusiastic industrial adopter, using vanadium steel in the chassis of the 1908 Model T for its unusual combination of strength and light weight, a choice that helped establish vanadium alloys as a mainstay of the automotive and tool-making industries.

Sefstrom named the element vanadium after Vanadis, an Old Norse byname of Freyja, the Norse goddess of beauty, love and fertility. He chose her because vanadium forms compounds of striking and varied colour, running through greens, blues, violets and yellows depending on their oxidation state, a beauty he thought worthy of the goddess. The naming is a rare instance of Norse rather than Greek or Roman mythology entering the periodic table, and it stands alongside thorium, named for Thor, as a Scandinavian chemist's tribute to the gods of the north. The choice is symbolic and aesthetic, honouring the colours of the compounds rather than any property of the metal itself.

Freyja is one of the most vivid figures of Norse mythology, associated with love, beauty, war and seidr magic, and Vanadis was among her several bynames, so Sefstrom's choice drew on a genuinely different mythological well than the Greek and Roman names that dominate the rest of the table. Vanadium also has a strange foothold in biology: certain marine invertebrates called ascidians, or sea squirts, concentrate vanadium in their blood cells at levels far above that of seawater, for reasons still not fully understood, giving them blood that can appear green rather than the iron-based red of vertebrate blood.