Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Uneven, UnevenArthur Thomas, Gemstones (2009)
Mg 3(SiO 4)(F,OH) 2Anthony et al , Handbook of Mineralogy (2001)
Cu 5(SiO 3) 4(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references