ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
ZrSiO 4Michael OâDonoghue , Gems, Sixth Edition (2006)
Ca 5(PO 4) 3FAnthony et al , Handbook of mineralogy (2001)