Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
(Zn,Mn2+ )OMichael OâDonoghue , Gems, Sixth Edition (2006)
ZrO 2Arthur Thomas , Gemstones (2009)