Colorless, Yellow, Blue, Reddish, Black, Reddish, Brown, Blue, gray, Black, Reddish, Brown, Blue, gray
Yellow, Brownish, Reddish, Green, Brownish, Yellow, Green, Yellow, Red
Subconchoidal, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
Uneven
TiO 2Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
(Fe+++,Al)25(PO4)17O6(OH)12•75(H2O)