USA, Zambia, Madagascar, India, Sri Lanka, Russia, Australia, Color: violet, purple-violet, Hardness: 7, Refractive index: 1.54 1.55, Density: 2.65 2.66, Chemical composition: SiO2, Crystal structure: hexagonal, Lustre: vitreous, Origins: Widespread; main sources are Brazil, Uruguay, Bolivia, Argentina, USA, East Africa, Zambia, Namibia, Madagascar, India, Sri Lanka, Russia, Brazil, Uruguay, Bolivia, Argentina, Australia, Brazil, Uruguay, Bolivia, Argentina, Australia