Subconchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Conchoidal
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
ZrSiO 4Michael OâDonoghue , Gems, Sixth Edition (2006)