ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Gems, Conchoidal, Brittle
Be 3Al 2Si 6O 18Ulrich Henn and Claudio C.
Ca 3Ti4+2(Fe3+2Si)O 12Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references