Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Subconchoidal, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
CaCO 3Ulrich Henn and Claudio C.
TiO 2Michael OâDonoghue , Gems, Sixth edition (2006) More from other references