ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
UnevenAnthony et al, Handbook of mineralogy (2001), UnevenAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Al 2(PO 4)(OH) 3Michael OâDonoghue , Gems, Sixth Edition (2006)
CaMoO 4Michael OâDonoghue , Gems, Sixth Edition (2006)