Colorless, Yellow, Blue, Reddish, Black, Reddish, Brown, Blue, gray, Black, Reddish, Brown, Blue, gray
Colorless, Green, Black, Brown, Red, Greenish, Yellow, gray
Subconchoidal, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
Conchoidal, Uneven, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
TiO 2Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
Ca 3Fe 2(SiO 4) 3Arthur Thomas , Gemstones (2009)