Uneven, UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Conchoidal, Uneven, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
(Na,Ca) 8Al 6Si 6O 24(SO 4,S,Cl) 2Ulrich Henn and Claudio C.
Ca 3Fe 2(SiO 4) 3Arthur Thomas , Gemstones (2009)