Vanadinite on a goethite matrix.These beautiful orange crystals are the main source of Vanadium and

Vanadinite on a goethite matrix.These beautiful orange crystals are the main source of Vanadium and a minor source of lead, being a lead-vanadium chloride within the apatite group. They are rare, only forming when lead ore deposits such as galena are oxidised, usually in arid climates, as circulating fluids alter the original rocks forming secondary minerals. The vanadium is leached from the wall rocks, and mixed with the lead before precipitation. Morocco is the best source for spectacular mineral specimens like this one, but it also occurs in Europe and the Americas. Discovered in Mexico in 1801, and originally named brown lead, their analysis led to the discovery of the element Vanadium. The mineral has also been known as Johnsonite. Crystallising in the hexagonal system, they usually have a six sided shape. It is both brittle and dense, and only has a hardness of 4 (same as a copper coin) on the Mohs scale. It gradually darkens on exposure to light, so specimens should be kept in a dark cabinet.LozLocation: Taouz Er Rachidia Province, Meknès-Tafilalet Region, MoroccoImage credit: Gery Parenthttp://webmineral.com/data/Vanadinite.shtmlhttp://www.mindat.org/min-4139.htmlhttp://www.minerals.net/mineral/vanadinite.aspx -- source link

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