Stolzite: Gemstones Information
Stolzite is PbWO4 and is dimorphous with raspite. It forms translucent reddish brown to yellow, sometimes bright orange dipyramidal crystals of the tetragonal system with hardness 3 and SG 8.3–8.4. The RI for the ordinary and extraordinary rays is 2.27 and 2.18–2.19, uniaxial negative with birefringence 0.080. Stolzite occurs as an uncommon mineral in the oxidized zone of hydrothermal tungsten-bearing lead deposits.Localities include the Kola peninsula, Russia and Broken Hill, New South Wales.