ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
{100} perfect; {110} and {1 1 0} good; {010} poor
Perfect on [10 1 1] three directions with angle of 74° 55
(Ca,Mn2+ )Si 3O 9Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
CaCO 3Ulrich Henn and Claudio C.