This heavy-duty rock tumbler does much more than ordinary rock polishers- it actually changes rough stones into beautiful high-luster semi precious gemstones (note: takes approximately 30 days to achieve). You can even make jewelry and key chains with the settings included in this set. This U.L. Listed set includes a tumbling machine with heavy-duty motor, rough semi-precious stones (including amethyst, jasper, agate and others), grit, polish, jewelry settings, glue and instruction manual. Ages 10 and up.