Which preposition to use with pyrite

in Occurrences 2%

Among them were specimens of copper pyrites in quartz, sulphate of strontian, foliated gypsum, and numerous calcareous petrifactions.

for Occurrences 1%

Where a sane man looks for strength and honesty that he can yoke up with, a Yussuf Dakmar spies out human failings; and whereas most of us in our day have mistaken pyrites for fine gold, which did not hurt more than was good for us, he ends by mistaking gold for dross.

on Occurrences 1%

When he saw that pyrites on Idaho Bar he stopped dead.

Which preposition to use with  pyrite