ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Not Available
(Zn,Mn2+ )OMichael OâDonoghue , Gems, Sixth Edition (2006)