Sub-Conchoidal, Irregular/uneven, Sub-Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Irregular/uneven, UnevenArthur Thomas, Gemstones (2009)
(Li,Na)Al(PO 4)(F,OH)Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
CaAl 2Si 4O 12 -6H 2OArthur Thomas , Gemstones (2009)