Some are too porous or have too many impurities. Others may show features that would be eliminated by grinding and polishing. Along the beaches and in most gravels, the stones have already been rounded by glacial and water action. Most of these are well suited for lapidary and the results are worth the effort. The Petoskey Stone is a good choice for polishing because it can be polished by hand.
Calcite is soft enough so it can be easily worked yet dense enough to take a nice polish.
Materials Needed for Hand Polishing Petoskeys Petoskey Stone - If the stone has been rounded by running water from the glaciers or waves on the beach, much of your initial shaping may have already been done. Polishing will go rather quickly. Grit refers to the size of the grains on a sandpaper. The higher the number, the finer the grain or grit. Sandpaper and most of the supplies you will need are available at hardware stores.