Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Uneven, UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
SrCO 3Walter Schumann , Gemstones of the world (2001) More from other references
(Na,Ca) 8Al 6Si 6O 24(SO 4,S,Cl) 2Ulrich Henn and Claudio C.