How can someone polish rocks?

To polish rocks, it is necessary to have a rock tumbler, water, abrasive 80, 220 and 400 grit, cerium oxide and rocks for polishing. The process can take between three and four weeks, depending on the rocks.

Take the following steps when polishing rocks.

1. Fill the rock tumbler with rocks, grit and water
Fill the rock tumbler about 75 percent full of rocks to polish. Add the water so that it reaches just above the rocks, and add about a tablespoon of 80 grit.
2. Let the machine run for a few days
Let the machine run for a few days, but take the rocks out periodically to examine them. When they look rounded, take them out, clean the stones and tumbler and then start the process again with 220 grit.
3. Start the final polish
Run the machine at 220 grit for about three to five days, but inspect them every so often to see if they are smooth. Clean the stones and tumbler thoroughly again, then repeat the process with 400 grit for the final polish. Allow the tumbler to run for seven days this time and do not add fresh grit as this can make the stones rough. 
4. Finish using cerium oxide
After the final polishing phase, clean the rocks and tumbler, then add similar measurements of water and rocks together. Place 1 teaspoon of cerium oxide in the machine and let it run for seven days to make the stones shine.