Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Uneven, Uneven, Gemstones of the world (2001) More from other references
Mg 3(SiO 4)(F,OH) 2Anthony et al , Handbook of Mineralogy (2001)
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references