Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
ConchoidalWalter Schumann, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Metallic
Na 8Al 6Si 6O 24(SO 4) · H 2OAnthony et al , Handbook of Mineralogy (2001)
Be 2BO 3(OH)Ulrich Henn and Claudio C.