ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
CaBe 2(PO 4) 2Michael OâDonoghue , Gems, Sixth Edition (2006)
ZrO 2Arthur Thomas , Gemstones (2009)