Origin
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
  
USA, Mexico, Brazil, Switzerland, Sri Lanka, Burma, Madagascar, Color: colorless, light yellow, light pink, Hardness: 7, Refractive index: 1.63 1.64, Density: 2.98 3.03, Chemical composition: Ca(B2Si2O8), Crystal structure: orthorhombic, Origins: USA, Mexico, Brazil, Germany, Switzerland, Sri Lanka, Burma, Madagascar, Japan. Colorless danburites are common, with light pink or yellowish stones being more rare and expensive. Only eye clean pieces are valuable.
  
Color
Violet, White, Colorless, Blue, Red, Green, Yellow, pink, Violet, pink
  
Yellow, Brown, Colorless, White, gray, Brownish, Yellow
  
For which Rashi?
Pisces, Scorpio, Sagittarius, Pisces, Scorpio, Sagittarius, Pisces, Scorpio, Sagittarius
  
Not Available
  
Fracture
Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001)
  
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle