Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references
Mg 3(SiO 4)(F,OH) 2Anthony et al , Handbook of Mineralogy (2001)
SiO 2 · nH 2OGemdat.org , Management Team (2012)