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