ConchoidalArthur Thomas, Gemstones (2009)
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
MnTa 2O 6Walter Schumann , Gemstones of the world (2001) More from other references
MgCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references