ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, Splintery, Conchoidal, Uneven, Splintery, Conchoidal, UnevenWalter Schumann
(Ca,Na) 2Ta 2O 6(O,OH,F)Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
SiO2