Great way to start a rock collection! Learn about the exciting hobby of rock tumbling with National Geographic. This set has a new and improved tumbling barrel and includes all the accessories you?ll need to start polishing dazzling gems. Rock tumbling is tons of fun and a great way to start an extraordinary rock collection. Use the included jewelry fastenings to create beautiful homemade jewelry! Contents and Features: ? High-quality tumbling machine with powerful motor that will last for years ? Upgraded leak-proof barrel with silicon lining ? ½ pound of stones from around the world (9 types) and four levels of grit ? Jewelry fastenings so you can create your own unique jewelry ? Full-color information guide with cool facts about each of the gemstones included ? Easy-to-follow rock tumbling instructions Rock tumbling is a fun activity for children of all ages and promotes an interest in geology and science. Introduce your kid to science the fun way, and join National Geographic as we inspire future generations by showing them the wonders of the natural world. National Geographic Toys is proud to provide a 100% satisfaction guarantee with all our products so that you can buy with confidence. About the National Geographic Society With a mission to inspire people to care about the planet, the 126-year-old National Geographic Society is one of the world?s largest nonprofit scientific and educational organizations. National Geographic?s net proceeds support vital exploration, conservation, research, and education programs.