Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Fe 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)
ZrSiO 4Michael OâDonoghue , Gems, Sixth Edition (2006)