Uneven, Uneven, Irregular, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)
Na(Mg 3)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)