ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)
Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
CaTiSiO 5Ulrich Henn and Claudio C.
PbSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references