Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009)
Na 3(Na,K)Al 4Si 4O 16Ulrich Henn and Claudio C.
Na 4AlBeSi 4O 12ClMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references