Polyhalite
.H2O 2%, Ca 1%, K 1%, Mg 1%, S 1%,

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) = 171.58


Minerals may vary in elemental composition and impurity levels.
Wikipedia Page:

Polyhalite
 is defined with respect to the entities below:
The entities below are defined with respect to:
Polyhalite
Mineral (generic)


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