Things You'll Need
Instructions
Find a metal or plastic cylinder-shaped container the size of a coffee can.
Fill half of the container with sand. Work with very coarse sand at first and then use finer sand progressively as the rocks get polished to your liking.
Create a gritty slurry by filling 1/3 of the container with water over the sand.
Put the rocks that you collected into the mixture. Secure a lid onto the can and be sure that it is very tight. Tape the lip down with duct tape if need be.
Shake and roll the tumbler vigorously for several days and check the polishing of the rocks as you go. Replace coarse with sand that is finer over time and continue rolling and shaking vigorously to get the desired polish level.