Colorless, White, Brownish, Reddish, Black, Brownish, Black, Colorless, gray, White, Reddish, Brown
White, Colorless, Blue, Red, Green, Yellow, Violet
Uneven
Uneven, Uneven, Gems, Sixth Edition (2006)
Na 3AlF 6Ulrich Henn and Claudio C.
Al 2O 3Michael OâDonoghue , Gems, Sixth Edition (2006)