Colorless, Colorless, Violet, White
Yellow, Green, Blue
Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references
Ca 3Al 2(SO 4)(F,OH) 10Ulrich Henn and Claudio C.
SiO 2 · nH 2OGemdat.org , Management Team (2012)