Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)
MgCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
CaTiSiO 5Ulrich Henn and Claudio C.