Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
ConchoidalWalter Schumann, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Metallic
Al 6B 5O 15(F,OH) 3Ulrich Henn and Claudio C.
Be 2BO 3(OH)Ulrich Henn and Claudio C.