ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
CaBe 2(PO 4) 2Michael OâDonoghue , Gems, Sixth Edition (2006)
(Zn,Mn2+ )OMichael OâDonoghue , Gems, Sixth Edition (2006)