ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Gemstones (2009), Splintery
NaAl 3(PO 4) 2(OH) 4 · 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Ca 2NaHSi 3O 9Ulrich Henn and Claudio C.