Tumbled or Polished crystals have been processed by hand and/or machine and Raw or Natural crystals have not - they are pretty much as they came out of the ground. Both Tumbled and Natural crystals are effective healers and protectors. They offer different energies however they are both positive and effective. The market for spectacular tumbled stones is very small. They are sold as "collector's pieces" or as rough to people who will cut them into cabochons. We do not believe that premium tumbled stones are an investment opportunity. Their intrinsic value is very low and they are very difficult to sell at a premium price. Tumbled stones are small, rounded, brightly polished pieces of rocks and minerals. They are made by placing rough rocks in a machine known as a rock tumbler, which tumbles them until their edges and surfaces are smooth and polished. Tumbled stones are pieces of rocks and minerals that have been rounded, smoothed and polished into beautiful gemstones in a rock tumbler.