Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Fe 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006)
SrCO 3Walter Schumann , Gemstones of the world (2001) More from other references