Uneven, Subconchoidal, Uneven, Subconchoidal, Conchoidal, Brittle
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
NaAlSi 2O 6 · H 2OMichael OâDonoghue , Gems, Sixth edition (2006) More from other references
Na 8Al 6Si 6O 24Cl 2Michael OâDonoghue , Gems, Sixth Edition (2006)