Uneven, Uneven, Gems, Sixth Edition (2006)
Sub-Conchoidal, Irregular/uneven, Sub-Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
None, but may exhibit parting
[100] Perfect, [110] Good, [011] Distinct
Al 2 O 3
(Li,Na)Al(PO 4)(F,OH)Michael OâDonoghue , Gems, Sixth edition (2006) More from other references