Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Mg 3(SiO 4)(F,OH) 2Anthony et al , Handbook of Mineralogy (2001)
CaCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references