Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
Ca 2 MgAl 2 BSi 4 O 15 OH Gemdat.org, Management Team (2012)
CaB 2(SiO 4) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references