Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001)
Al 6B 5O 15(F,OH) 3Ulrich Henn and Claudio C.
Na(Li 1.5Al 1.5)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012) Formula given for elbaite.