ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), (e.g. graphite).
CaBe 2(PO 4) 2Michael OâDonoghue , Gems, Sixth Edition (2006)
PbCrO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references