Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
BaTiSi 3O 9Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
ZrO 2Arthur Thomas , Gemstones (2009)