Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), (e.g. graphite).
Mg 3(SiO 4)(F,OH) 2Anthony et al , Handbook of Mineralogy (2001)
PbCrO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references