White, Colorless, Blue, Red, Green, Yellow, Violet
Green, White, gray, Green, White, gray
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Fibrous, Difficult, Fibrous
(Ca,Mg,Mn)SiO 3Gemdat.org , Management Team (2012)
Al(OH)3