UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Uneven
Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
FeS 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Mg 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006)