White, Colorless, Blue, Red, Green, Yellow, Violet
Colorless, Blue, Violet, White, Brown, Colorless, Blue, Violet, White, rose, Brown, gray, Colorless, White, Violet, gray, Colorless, White, Violet, gray
Not Available
Conchoidal, Brittle, Conchoidal, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
SiO 2 (with trace Cr minerals) Gemdat.org , Management Team (2012)
CaSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references