ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
CaBe 2(PO 4) 2Michael OâDonoghue , Gems, Sixth Edition (2006)
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.