Irregular/uneven, UnevenArthur Thomas, Gemstones (2009)
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
CaAl 2Si 4O 12 -6H 2OArthur Thomas , Gemstones (2009)
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.