Vermiculite
.H2O 4%, Al 2%, H 2%, Mg 3%, O 12%, Si 2%,

estimated elemental composition and molecular weight 
Minerals with the same name may vary widely in appearance and composition, and very few are >99% (reagent grade) pure.

Gram formula weight (molecular mass) = 449.13


Minerals may vary in elemental composition and impurity levels. The formula given is an approximation.
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Vermiculite
is defined with respect to the entities below:
The entities below are defined with respect to:
Vermiculite
Mineral (generic)


chemical compound molecule metal molecular science reaction mechanism ionic material acid base geometry reactivity synthesis science knowledge chemistry Lewis