Uneven, Subconchoidal, Uneven, Subconchoidal, Splintery, UnevenArthur Thomas, Gemstones (2009)
Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Good on {110}, poor on {100}
Perfect on {010} imperfect on {100}
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
Mg 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006)