Uneven, Subconchoidal, Uneven, Subconchoidal, Splintery, UnevenArthur Thomas, Gemstones (2009)
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
Good on {110}, poor on {100}
None, may show partings on {0001} and {10 1 1}
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
Fe 2O 3Arthur Thomas , Gemstones (2009)