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