Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
ConchoidalWalter Schumann, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Metallic
Na 3(Na,K)Al 4Si 4O 16Ulrich Henn and Claudio C.
Be 2BO 3(OH)Ulrich Henn and Claudio C.