Rock tumbling is becoming a popular hobby. Rock tumbling is a slow, step-by-step process, with each step taking anywhere from five to 10 days. These beautiful stones will be turned into rings, pendants, belt buckles and money clips, so polishing these rocks to perfection is not only an art, it's a necessity. Cerium oxide is the standard polishing compound used in the fourth step. However, there is a final burnishing step that will give your stones that perfect high gloss polish.
You don't have to use commercial grit and polish to tumble rock but they do speed up the process, giving you better results. However, silica sand is an element that will work in your tumbler to polish your stones. The process will take a couple weeks longer than commercial rock tumbling grit, though. Sinterblast is an economical brown sintered aluminum oxide blasting grit. This grit can be used for rock tumbling and polishing. Sinterblast is gaining in popularity and is also recyclable. It comes in 30, 36 and 60 grades. Never overfill your tumbler or your rocks will not polish up correctly.
You can purchase corncobs impregnated with polish, or use walnut shells instead of water. They are both good polishing substitutes. A thick mixture of water and sugar is called slurry. This sugar slurry mixture added in the final polishing stage is good because the protective slurry allows the rocks to slide over each other without the damaging collisions. Some use Karo syrup instead of water. It's wise to use a pure soap such as grated Ivory soap or powder and water in the final burnishing stage of polishing, which will clean and shine your stones to perfection.
To protect your stones from chipping and damage, use some type of polishing filler in the final polishing stages. Clean plastic pellets can be added to absorb harsh tumbling conditions. The plastic pellets can also be recycled. However, make sure they are not impregnated with grit because they may scratch your stones in the final stage. Cut up rubber bands, pea-sized river stones, cornmeal, sawdust and wood shavings can all be used in the final polishing stage. These fillers will protect your stones from banging into each other as they tumble. Do not try to polish soft rocks and hard rocks in the same batch because only the hard rocks will polish.