Colorless, Green, Yellow, White, Colorless, Green, Yellow, White
Colorless, White, Brownish, Reddish, Black, Brownish, Black, Colorless, gray, White, Reddish, Brown
Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Uneven
Mg 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006)
Na 3AlF 6Ulrich Henn and Claudio C.