Translations:AY Honors/Petoskey Stone/Answer Key/58/en
From Pathfinder Wiki
You can't use a standard rock polisher on a Petoskey stone because they are too soft and brittle and a rotary tumbler can easily erode their delicate structures, leaving them with mud instead of a polish. However, with precautions like using a very gentle tumble, shorter times, and added cushioning media, it is possible to use a tumbler for the initial shaping and smoothing stages. Many recommend a vibratory tumbler or hand-polishing for the final shine.
