Vanadinite
Vanadinite is an uncommon mineral, only occurring as the result of chemical alterations to a pre-existing material.He called the mineral "brown lead" and asserted that it contained a new element, which he first named pancromium and later, erythronium.Del Río's "brown lead" was also rediscovered, in 1838 in Zimapan, Hidalgo, Mexico, and was named vanadinite because of its high vanadium content.[6] Vanadinite occurs as a secondary mineral in the oxidized zone of lead-bearing deposits; the vanadium is leached from wall-rock silicates.[4] Deposits of vanadinite are found worldwide including Austria, Spain, Scotland, the Ural Mountains, South Africa, Namibia, Morocco, Argentina, Mexico, and four states of the United States: Arizona, Colorado, New Mexico, and South Dakota.Common impurities of vanadinite include phosphorus, arsenic and calcium, where these may act as an isomorphic substitute for vanadium (in the first two cases) or lead (in the second).[3][5] Vanadinite is usually bright-red or orange-red in colour, although sometimes brown, red-brown, grey, yellow, or colourless.[3][5][7] Along with carnotite and roscoelite, vanadinite is one of the main industrial ores of the element vanadium, which can be extracted by roasting and smelting.