Drop in rough, dull rocks, let the machine do its thing, and weeks later out come glossy, polished gems.

This is the advanced rock tumbler from Dan and Darci. A rubber barrel slowly turns your rocks with water and grit, wearing them smooth over several stages, from coarse grit down to polish. The digital timer lets you set how long each stage runs, and the barrel is built to run quietly.

It's real geology happening on your counter, and kids are amazed when they see the before and after. The kit comes with everything to start, including rough stones, so you can begin the day it arrives. Grown-ups get hooked too, and start picking up rocks on every walk.

What's in the box

• Rock tumbler with digital timer and power cord.
• Low-noise rubber barrel (1 lb capacity).
• Four grit packets, from coarse to final polish.
• Half a pound of assorted rough stones.
• Mesh strainer, spare motor belt and rock storage bags.
• Jewellery fasteners to turn your stones into necklaces.
• Instruction booklet and learning guide.

How to use it

• Start with the included rough stones
• Run each grit stage, rinsing in between
• Add rocks you find on walks or trips
• Turn finished stones into jewellery

Care: Rinse the barrel well between grit stages, and never pour used grit down the sink, since it can block your drain.