White, Colorless, Blue, Red, Green, Yellow, Violet
White, Colorless, Greenish, White, Colorless, gray, pink, Greenish, White, Greenish, Reddish
ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Subconchoidal, Uneven, Subconchoidal, Conchoidal, Brittle
Tourmaline is a series of several different minerals with unique chemical formulas.
NaAlSi 2O 6 · H 2OMichael OâDonoghue , Gems, Sixth edition (2006) More from other references