The Rock STEM Tumbler Kit, 3 lb Rough Stones, Grit and GemFoam Polish

A complete rock tumbling kit built around a leak-proof barrel with a stainless steel lid, which the maker rates at about 75% quieter than an all-plastic barrel. Speed control and an automatic shut-off timer let you set each grit stage and leave it running.

Everything needed to finish a batch is in the box: 3 lb of rough rock in nine gemstone types, four levels of grit, a strainer, GemFoam polish and five jewelry fastenings, so the stones that come out can go straight onto a cord or a keyring. A full rough-to-polish cycle takes roughly four weeks. 12.6 x 10.3 x 6.7 in, 10.5 lb.