As 1%, Co 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) = 165.91

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

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