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