ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Be 3Al 2Si 6O 18Ulrich Henn and Claudio C.
Mg 3B 7O 13ClMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references