Rock Discoveries

Master the Art of Rock Tumbling: Tips and Tricks You Need to Know

Rock Tumbling Tips and Tricks: Everything You Need to Know

Rock tumbling is a fun and rewarding hobby that can transform rough rocks into beautiful, polished gems. However, it’s not as simple as throwing rocks into a tumbler and pressing a button.

It takes time, patience, and a bit of know-how to produce excellent results. In this article, we’ll share some rock tumbling tips and tricks that will help you get the most out of your tumbling experience.

Contain Your Tumbling

One of the essential things you need to do when tumbling rocks is to contain your tumbling. Use a plastic bin, rubber, or metal baking pan to keep the noise down and prevent the rocks from bouncing all over the place.

It’s also a good idea to place the tumbler on a soft surface to reduce noise further.

Use Dish Soap

When tumbling, it’s essential to use powdered dish soap to remove grit build-up from the rocks. Grit build-up can reduce tumbling efficiency, and it may take longer to produce polished rocks.

Adding about a tablespoon of powdered dish soap helps dissolve grease and other contaminants from the rocks, which makes them more efficient when tumbling.

Separate Polishing and Grit Barrels

It’s crucial to separate polishing and grit barrels to avoid causing damage to polished rocks by leftover grit. You don’t want all the hard work to get ruined by leaving behind undesired grit in the barrel.

So, be careful when using different barrels and clean them thoroughly between steps to avoid any leftovers.

Clean Barrel Between Steps

Cleaning the barrels between steps is an essential step in rock tumbling. If there is wet sludge or dried grit left in the barrel, it can contaminate your next tumbling batch, resulting in poorly polished rocks.

The best way to clean the barrel is by using a hard-bristled toothbrush.

Remove Problematic Rocks

Remove grit-containing rocks before entering the tumbling process, as they can cause damage to other rock specimens. To do this, use tweezers or pliers to remove any rocks with identifiable grit.

It’s also important to get rid of rocks with cracks, voids, or large inclusions. These rocks can damage other rocks and negatively impact the tumbling results.

Use a Toothbrush

One of the best ways to remove grit from rocks is by using a hard-bristled toothbrush. Wet the rock and scrub away any remaining grit on the surface.

Make sure to clean all the crevices and pores in the rock. For hard-to-reach areas, use a toothpick to scrape off the grit.

Cover Your Tumbler

If you find tumbling sounds uncomfortable or dislike excessive noise pollution, it’s best to cover your tumbler. You can use a cardboard box, blankets, or pillows to reduce noise.

Covering the tumbler will help keep noise to a minimum, especially if you tumble rocks overnight.

Use Suitable Rocks

When picking rocks to tumble, choose thin and small rocks that don’t have imperfections, deep cracks, or worn surfaces. Large rocks take longer to tumble and may not get polished evenly.

Select rocks with smooth surfaces and a Mohs hardness scale of at least seven for best results. Avoid porous or gritty rocks as they can lose their shape or break apart during tumbling.

Save Tumbling Media

Plastic beads or ceramic media are essential to smooth the surfaces of the rocks and provide contact points. Save these for your next tumbling experience.

For best results, place the beads or ceramic media in a Tupperware container for storage.

Vary Rock Sizes

Varying the rock sizes in the tumbler provides more contact points between the rocks and, as a result, a more efficient tumbling process. Use ceramic media to fill in the empty spaces, as it’s lighter than rocks and can conform to the rock’s shape to provide more contact points.

Keep Track of Results

It’s essential to keep track of the grit size, rock types, and tumbler speeds used for each batch. This information will help you determine the optimal parameters for tumbling the rocks.

Once you’ve collected enough data, you can use the results to draw conclusions about which grit sizes and types of rocks work best in your tumbler. Select Hard, Dense, and Smooth Rocks

Mohs hardness scale measures mineral hardness from scale 1, the softest mineral, to scale 10, the hardest mineral.

When selecting rocks for tumbling, look for hard, dense, and smooth rocks because they polish more evenly and hold up better under stress. Avoid rocks with grainy spots, as these might be weaker and lead to breakage during the tumbling process.

Be Patient

Tumbling rocks is a slow process, and it may take several weeks to finish the process. Removing softer rocks too early can impact the texture and result in poorly-polished rocks.

So, be patient and wait it out for a few more rounds until you find that the polishing process has been completed correctly.

Leaving the Tumbler On

One of the most common questions about rock tumbling is whether to leave the tumbler on continuously or turn it off periodically. Ideally, it’s best to keep the tumbler running continually unless you’re changing the barrels or adding more grit.

Leaving the tumbler on helps produce more uniform rounding and polishing of the rocks.

Identifying Rocks Suitable for Tumbling

Identifying rocks suitable for tumbling takes knowledge of the Mohs hardness scale and texture. The Mohs hardness scale measures mineral hardness, and the ideal range of hardness for tumbling is between seven and nine.

Rocks with a uniform surface texture polish more evenly and efficiently.

Selecting Rocks for Tumbling

When selecting rocks for tumbling, choose hard and dense rocks with no voids, pore spaces, or fractures. Select rocks that are evenly textured and have no cracks.

If the rock has many imperfections, it will quickly break up or lose its shape during tumbling.

Rocks to Avoid Tumbling

Sandy, gritty, and grainy rocks are usually a poor choice for tumbling. They have void spaces that trap grit, leading to deep scratches and poor polishing.

Rocks with fractures, void spaces, or large inclusions are also discouraged because they can damage other rocks and result in uneven tumbling.

Over-Tumbling Rocks

Over-tumbling softer rocks is one of the most common mistakes people make when tumbling rocks. It’s best to stop when the rocks are entirely shaped and not polished further.

Failing to remove over-tumbling softer rocks will result in significant polishing and lead to poor polishing of identical rock specimens.


In conclusion, rock tumbling is an enjoyable and rewarding pastime with a little knowledge and common sense. By following the tips discussed in this article, you can produce beautiful, polished rocks that you can be proud of.

Remember to be patient during the tumbling process and take note of your tumbling parameters to determine which grit sizes and rock types work best for you. In conclusion, rock tumbling requires knowledge, patience, and attention to detail to produce beautiful and polished rocks.

By applying the tips and tricks mentioned in this article, you can maximize your efficiency and gain the full potential of your rock tumbling experience, creating stunning results. Check out our frequently asked questions below for additional tips and insights.


– How do I clean the barrel between steps? Use a hard-bristled toothbrush to remove any wet sludge or dried grit left in the barrel thoroughly.

– Can I vary the rock sizes during the tumbling process? Varying rock sizes can increase contact points between rocks, but it is essential to use ceramic media to fill in the empty spaces.

– How long should I tumble the rocks? It takes several weeks to complete the tumbling process fully, so be patient and avoid removing softer rocks too early.

– How can I identify suitable rocks for tumbling? Look for hard, dense, and smooth rocks with a uniform texture, between a Mohs hardness scale of seven and nine.

– Is it better to turn off the tumbler periodically or leave it on continuously? It’s best to keep the tumbler running continuously unless changing the barrels or adding grit.

– Should I avoid tumbling rocks with fractures, void spaces, or large inclusions? Yes, it’s essential to avoid these rocks because they can damage other rocks and result in uneven tumbling and scratches.

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