Colorless, White, Yellow, Green, White, pink, Green, Yellow, Violet, White, pink, Green, Yellow, Violet
Colorless, Blue, Violet, White, Brown, Colorless, Blue, Violet, White, rose, Brown, gray, Colorless, White, Violet, gray, Colorless, White, Violet, gray
Uneven, Brittle, Uneven, Brittle, Uneven
Conchoidal, Brittle, Conchoidal, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Perfect on {001}, imperfect on {110}
Rare tabular and prismatic crystals. Usually occurs as fibrous, parallel veins that break off into cleavage fragments.
(K,Na)Ca4Si8O20(F,OH)•8(H2O)
CaSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references