Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Uneven, Subconchoidal, Uneven, Subconchoidal, Splintery, UnevenArthur Thomas, Gemstones (2009)
(Cs,Na)(AlSi 2O 6) · 0.5H 2OWalter Schumann , Gemstones of the world (2001) More from other references
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references