ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Be 3Al 2Si 6O 18Ulrich Henn and Claudio C.
(Zn,Mn2+ )OMichael OâDonoghue , Gems, Sixth Edition (2006)