Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Fe 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006)
Mg 3(Al,Cr) 2(SiO 4) 3Gemdat.org , Management Team (2012)