Turn rough rocks into beautiful, polished stones that you can use to make charms, bracelets, keychains, and more. Begin by tumbling the included rocks in a barrel with water and grit, then repeat this cycle using progressively finer grits. In just weeks, the Smithsonian Rock Tumbler mimics the process that takes oceans thousands of years! Turn rough rocks into beautiful, polished stones! Includes accessories to make charms, bracelets, and keychains. Mimics the same process as the ocean. STEM content teaches about different types of rocks and how they form. Ages 10+