Colorless, Blue, Violet, White, Brown, Colorless, Blue, Violet, White, rose, Brown, gray, Colorless, White, Violet, gray, Colorless, White, Violet, gray
Yellow, Brownish, Reddish, Green, Brownish, Yellow, Green, Yellow, Red
Conchoidal, Brittle, Conchoidal, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Uneven
CaSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
(Fe+++,Al)25(PO4)17O6(OH)12•75(H2O)