Spain, Brazil, USA, Sri Lanka, Burma, Color: strongly pleochroic, reddish brown, pink / yellowish green, Hardness: 7 7.5, Refractive index: 1.63 1.65, Density: 3.13 3.21, Chemical composition: Al2SiO5, Crystal structure: orthorhombic, Lustre: vitreous, greasy, Origins: Spain, Brazil, USA, Sri Lanka, Burma. Discovered in Andalusia (Spain), the andalusite stone is relatively rare, with big crystals over 10 ct. especially rare. Due to its remarkable pleochroism effect, the stone is highly valued by collectors., brown
USA, Southern and central Africa, green, blue, China, India, USA, Italy, green, blue, China, India, USA, Italy
Brown, pink, Violet, Yellow, Green, White, gray, Colorless, Green, gray, Brown, Red
White, Yellow
Uneven, Subconchoidal, Uneven, Subconchoidal, Splintery, UnevenArthur Thomas, Gemstones (2009)
Uneven, Uneven, Gemstones of the world (2001) More from other references
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references