Uneven, Subconchoidal, Uneven, Subconchoidal, Splintery, UnevenArthur Thomas, Gemstones (2009)
Subconchoidal, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
Good on {110}, poor on {100}
Perfect on [001] and [011]
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
TiO 2Michael OâDonoghue , Gems, Sixth edition (2006) More from other references