ConchoidalArthur Thomas, Gemstones (2009)
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
MnTa 2O 6Walter Schumann , Gemstones of the world (2001) More from other references
ZrSiO 4Michael OâDonoghue , Gems, Sixth Edition (2006)