UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
Subconchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Na 8Al 6Si 6O 24Cl 2Michael OâDonoghue , Gems, Sixth Edition (2006)
Ca 6Si 2(CO 3) 2(SO 4) 2(OH) 12 · 24H 2OUlrich Henn and Claudio C.