Colorless, Brown, Greenish, gray
Colorless, Reddish, White, pink, Green, Yellow, Violet, White, pink, Green, Yellow, Violet, White, Colorless, Blue, Green, Brown, Yellow, pink, Violet, White, pink, Green, Yellow, Violet
Gems, Sixth Edition (2006), Gems, Sixth Edition (2006), Uneven
Uneven, UnevenArthur Thomas, Gemstones (2009)
Na(90-70%)Ca(10-30%)(Al,Si)AlSi 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)
KCa 4Si 8O 20(F,OH) · 8H 2OUlrich Henn and Claudio C.