1 in stock
Mineral : Vanadinite Crystals 23
Size Matrix 2″ x 1 1/2 ”
Crystals are the brightly red xls but in this case they are brown that is why the price is lower and the color red is not that common in the mineral world
Location: Mibladen and Touisset
Vanadinite is a mineral belonging to the apatite group of phosphates, with the chemical formula Pb5(VO4)3Cl. It is one of the main industrial ores of the metal vanadiumand a minor source of lead. A dense, brittle mineral, it is usually found in the form of red hexagonal crystals. It is an uncommon mineral, formed by the oxidation of lead ore deposits such as galena. First discovered in 1801 in Mexico, vanadinite deposits have since been unearthed in South America, Europe, Africa, and in other parts of North America.
Vanadinite is an uncommon mineral, only occurring as the result of chemical alterations to a pre-existing material. It is therefore known as a secondary mineral. It is found in arid climates and forms by oxidation of primary lead minerals. Vanadinite is especially found in association with the lead sulfide, galena. Other associated minerals include wulfenite, limonite, and barite.
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. In 1830, Nils Gabriel Sefström discovered a new element, which he named vanadium. It was later revealed that this was identical to the metal discovered earlier by Andrés Manuel del Río. Del Río’s “brown lead” was also rediscovered, in 1838 in Zimapan, Hidalgo, Mexico, and was named vanadinite because of its high vanadium content. Other names that have since been given to vanadinite are johnstonite and lead vanadate
Vanadinite occurs as a secondary mineral in the oxidized zone of lead-bearing deposits, the vanadium is leached from wall-rock silicates. Associated minerals includemimetite, pyromorphite, descloizite, mottramite, wulfenite, cerussite, anglesite, calcite, barite, and various iron oxide minerals.
Deposits of vanadinite are found worldwide including Austria, Spain, Scotland, the Ural Mountains, South Africa, Namibia, Morocco, Argentina, Mexico, and 4 states of the United States: Arizona, Colorado, New Mexico, and South Dakota. Vanadinite deposits are found in over 400 mines across the world. Notable vanadinite mines include those at Mibladen and Touisset in Morocco; Tsumeb, Namibia;Cordoba, Argentina; and Sierra County, New Mexico, and Gila County, Arizona, in the United States
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. Vanadinite is also occasionally used as a source of lead. A common process for extracting the vanadium begins with the heating of vanadinite with salt (NaCl) or sodium carbonate (Na2CO3) at about 850 °C to produce sodium vanadate (NaVO3). This is dissolved in water and then treated with ammonium chloride to give an orange-colored precipitate of ammonium metavanadate. This is then melted to form a crude form of vanadium pentoxide (V2O5). Reduction of vanadium pentoxide with calcium gives pure vanadium
|Colour||Bright red, orange-red, red-brown, brown, yellow, grey or colourless, may be concentrically zoned|
|Crystal habit||Prismatic or nodular; may be acicular, hairlike, fibrous; rarely rounded, globular|
|Crystal system||Hexagonal dipyramidal 6/m|
|Dimensions||2 × 2 × 2 in|