Colorless, Blue, Violet, White, Brown, Colorless, Blue, Violet, White, rose, Brown, gray, Colorless, White, Violet, gray, Colorless, White, Violet, gray
Colorless, Grey, gray
Conchoidal, Brittle, Conchoidal, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Not Available
CaSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
Ca 3B 6O 6(OH) 12 · 2H 2OAnthony et al , Handbook of Mineralogy (2001)