Mimetite
As 3%, Cl 1%, O 12%, Pb 5%,

estimated elemental composition and empirical formula 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) = 1488.2


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

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


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