Can I Polish Petosky Stones in my Rock Tumbler?

We recently received this question from a customer. Here is our answer:

Petosky stones are really hard to polish.

In the polish step, replace the water with corn syrup. Use Tin oxide polish only with clean plastic pellets.

You should also add a couple of tablespoons of vinegar.

If this doesn’t work, nothing will in a tumbler.

Most petosky stones are polished by hand and not in a tumbler.