Sub-Conchoidal, Irregular/uneven, Sub-Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
[100] Perfect, [110] Good, [011] Distinct
Perfect on {110} at 56° and 124°; partings on {010} and {100}
(Li,Na)Al(PO 4)(F,OH)Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.