Russia, Southern and central Africa, Color: green, yellowish green, Hardness: 6.5, Refractive index: 1.88 1.89, Density: 3.82 3.85, Chemical composition: Ca3Fe2(SiO4)3, Crystal structure: isometric, Origins: Russia, Namibia
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.