Colorless, White, Yellow, White, Greenish, gray, Brown, Colorless, Yellow
Colorless, White, Yellow, Green, White, pink, Green, Yellow, Violet, White, pink, Green, Yellow, Violet
Conchoidal, Brittle, Conchoidal
Uneven, Brittle, Uneven, Brittle, Uneven
{010} perfect, {110} distinct, {100} in traces
Perfect on {001}, imperfect on {110}
AlO(OH)Walter Schumann , Gemstones of the world (2001) More from other references
(K,Na)Ca4Si8O20(F,OH)•8(H2O)