Southern and central Africa
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.
Green
Yellow, Brown, Colorless, White, gray, Brownish, Yellow
Uneven
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
K(Al,Cr) 3Si 3O 10(OH) 2Gemdat.org , Management Team (2012)
CaB 2(SiO 4) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references