Hand-polished rocks, using a Dremel. I have a tumbler but use it strictly for metals so this would give me another reason to buy a Dremel and a billion attachments. Dremel Werkzeugprojekte, Dremel Bits, Dremel Carving, Dremel Sander, Stone Crafts, Rock Crafts, Diy And Crafts, Arts And Crafts, Dremel Tool Projects