Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Uneven, Uneven, Gems, Sixth Edition (2006)
SrCO 3Walter Schumann , Gemstones of the world (2001) More from other references
CaAl 2Si 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)