UnevenAnthony et al, Handbook of mineralogy (2001), UnevenAnthony et al, Handbook of mineralogy (2001)
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references, Brittle
Na(Mn2+ ,Ca) 2Si 3O 8(OH)Michael OâDonoghue , Gems, Sixth Edition (2006)
SiO2 · nH2O