Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Perfect on [10 1 1] three directions with angle of 74° 55
Poor on {120}, in traces on {001}
CaCO 3Ulrich Henn and Claudio C.
TiO 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references