Subconchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Uneven
Ca 6Si 2(CO 3) 2(SO 4) 2(OH) 12 · 24H 2OUlrich Henn and Claudio C.
ThCa 2Si 8O 20Walter Schumann , Gemstones of the world (2001) More from other references