Colorless, White, Brownish, Reddish, Black, Brownish, Black, Colorless, gray, White, Reddish, Brown
White, Colorless, Blue, Red, Green, Yellow, Violet
Uneven
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Na 3AlF 6Ulrich Henn and Claudio C.
(Ca,Mg,Mn)SiO 3Gemdat.org , Management Team (2012)