Uneven, UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
UnevenAnthony et al, Handbook of mineralogy (2001) More from other references, UnevenAnthony et al, Handbook of mineralogy (2001) More from other references, Brittle, Metallic
(Na,Ca) 8Al 6Si 6O 24(SO 4,S,Cl) 2Ulrich Henn and Claudio C.
CoAsSAnthony et al , Handbook of mineralogy (2001)