Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, Brittle, Metallic, Gemstones (2009)
Ca 3Al 2(SO 4)(F,OH) 10Ulrich Henn and Claudio C.
Na 2[Al 2Si 3O 10] · 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references