Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Ca 3Al 2(SO 4)(F,OH) 10Ulrich Henn and Claudio C.
Mg 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006)