Vanadium

Vanadium is a chemical element (atomic number 23). It was first discovered in lead bearing minerals in 1801. Originally named Erthronium (from "red"), it was mistakenly thought to be identical to chromium and was later "re-discovered" and given it's current name, derived from "Vanadis" a Scandinavian goddess of fertility and beauty. In 1867, it was isolated in pure form for the first time. Like aluminum, it is never found in it's pure state in nature, but once isolated as a metal, it forms an oxide that prevents further corrosion. 
Vanadium's role in living organisms is poorly understood. Although some vanadium compound are toxic, it also appears to be used as a micronutrient in some enzymes.
The current medical consensus is that all vanadium compounds should be considered toxic. However, it is sold in low concentrations as a health supplement, although its effeictiveness is very much in question.
Vanadium at Wikipedia
Category:Chemistry