Yellow, Brown, Black, Colorless, White, Brownish
White, Colorless, Blue, Red, Green, Yellow, Violet
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Not Available
MgCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
SiO 2Ulrich Henn and Claudio C.