Uneven, Uneven, Gemstones of the world (2001) More from other references
Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references
Mg 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006)