Vanadinite

Vanadinite

Vanadinite is an uncommon mineral, only occurring as the result of chemical alterations to a pre-existing material. 

It was originally discovered in Mexico by the Spanish mineralogist Andrés Manuel del Río in 1801. He called the mineral "brown lead" and asserted that it contained a new element, which he first named pancromium and later, erythronium. However, he was later led to believe that this was not a new element but merely an impure form of chromium (Later named Vanadium)