ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Ca 5(F,Cl)(PO 4) 3Arthur Thomas , Gemstones (2009)
KAlSi 2O 6Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references