Vanadinite: Gemstones Information

Vanadinite is Pb5(VO4)3Cl and forms subtransparent to opaque redorange, deep red or brownish red well-developed hexagonal prismatic crystals of the hexagonal system with subresinous to adamantine lustre,hardness 2.5–3 and SG in the range 6.5–7.1.The RI for the ordinary and extraordinary rays is 2.416 and 2.350, uniaxial negative with birefringence 0.066. Vanadinite occurs as a secondary mineral in the oxidized zone of lead-bearing deposits. Fine crystals are found at a number of locations, including the Red Cloud mine, Silver district, Yuma County,Arizona, USA and at Mibladen, Morocco.