Uneven, Subconchoidal, Uneven, Subconchoidal, Splintery, UnevenArthur Thomas, Gemstones (2009)
Uneven, Gemstones (2009), Splintery
Good on {110}, poor on {100}
Perfect on {100} and {001}
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
Ca 2NaHSi 3O 9Ulrich Henn and Claudio C.