Vanadinite

vanadinite

wulfenite

hopeite

descloizite

Images

Formula: Pb5(VO4)3Cl
Anhydrous vanadate containing halogen, apatite group, apatite supergroup
Crystal System: Hexagonal
Specific gravity: 6.88 measured, 6.95 calculated
Hardness: 3
Streak: White, yellowish
Colour: Yellow, brown, orange, red
Solubility: Moderately soluble in hydrochloric acid; readily soluble in nitric acid
Common impurities: P,As,Ca
Environments:

Hydrothermal environments

Vanadinite is a rare secondary mineral found in the oxidation zone of high temperature hydrothermal lead deposits in arid climates, associated with other secondary lead minerals. The vanadium is leached from wall-rock silicates.
Associated minerals include mimetite, pyromorphite, descloizite, limonite, mottramite, wulfenite, cerussite, anglesite, calcite, baryte and iron oxides (HOM, Mindat).
Vanadinite crystallises in the hexagonal system, point group 6/m. Crystals are common, mostly prismatic with forms {1010} and {0001} or tabular parallel to {0001} (OJ).

Localities

At the Cruz del Sur mine, Veinticinco de Mayo Department, Río Negro Province, Argentina, The lead-zinc-copper deposits occur as fissure-filling veins at the boundary between andesite and rhyolite. The oxidation zone contains many secondary minerals including vanadinite (AM 63.1175-1181).

At the Braeside lead field, East Pilbara Shire, Western Australia, vanadinite occurs as a secondary mineral on exposed surfaces and in cavities, associated with pyromorphite, descloizite and mottramite. Some samples occur as hoppered prisms consisting party of a solid frame of vanadinite up to 10 microns wide filled by a mixture of iron oxides, pyromorphite, vanadinite and kaolinite (AJM 13.2.61-62).

At the Shangri La Mine, Kununurra, Wyndham-East Kimberley Shire, Western Australia, vanadinite occurs as mm sized crystals that encrust quartz, and may be associated with mottramite (AJM 16.1.22).

At the Apex mine, San Carlos, Manuel Benavides Municipality, Chihuahua, Mexico, well crystallised specimens of vanadinite to 6 cm occur as simple hexagonal prisms, in some cases modified by pyramid faces and commonly hoppered. The orange-red to red-brown or brown crystals of vanadinite are commonly intergrown with small translucent white calcite crystals (Minrec 39.6.62).

At Touissit, Oujda, Morocco, mimetite pseudomorphs after vanadinite have been found with mottramite (KL p207).

At the Abenab Mine, Grootfontein, Otjozondjupa Region, Namibia, the largest vanadinite crystals in the world, over 12 cm long, have been collected, The crystals tend to have an inner red vanadinite core with an outer coating of grey-green descloizite (BC).

At the Kafferskraal Farm, Ngaka Modiri Molema District, North West, South Africa, vanadinite crystals to 1 cm occur associated with cerussite, galena, minium, pyromorphite and massicot (BC).

At the Whitwell quarry, Derbyshire, England, UK, vanadinite occurs on a baryte-phosphohedyphane matrix (RES p139).

At the Judkins quarry, Nuneaton, Warwickshire, England, UK, vanadinite occurs with mottramite (RES p325).

From Wanlockhead, Dumfries and Galloway, Scotland, UK, sample BM.1964,R8179 from the Natural History Museum, London, features lustrous, pale brown, glogular aggregates of intergrown heagonal prismatic crystals of vanadinite, richly scattered over a matrix of cream to grey vanadinite and mottramite (RES2 p130).

At the Red Cloud mine, Arizona, USA, vanadinite pseudomorphs after wulfenite have been found (KL p207).

At the Kabwe mine, Central Province, Zambia, vanadinite is associated with hopeite and descloizite (R&M 94.2.142-143).

Back to Minerals