Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Irregular/uneven, UnevenAnthony et al, Handbook of mineralogy (2001), Brittle, Uneven
Mg 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006)
CaAl 2Si 3O 10 · 3H 2OUlrich Henn and Claudio C.