Buying guide for Best rock tumblers
A rock tumbler can expose the inner beauty of stones you find on your travels, at the beach or in your backyard, polishing their rough exterior to reveal layers and colors. This isn’t a difficult hobby, but it requires patience, a handful of supplies and accessories, and a bit of trial and error.
The two primary types of rock tumblers, rotary and vibratory, operate at different speeds and produce slightly different results. If you’re just starting out, consider a smaller, less expensive model to learn the tumbling process and find out what types of rocks give you the results you want. The more common rotary tumblers are best suited for polishing irregularly shaped rocks that have angles or points, though this process takes about a month. Vibratory tumblers shake rocks to polish them in as little as a week, but the rocks must be fairly round to begin with for best results.
The size of the tumbler determines how many rocks you can polish at once, and some high-end models have two tumblers for polishing twice as fast or tumbling rocks with different grit levels. If you have a small living space, you should also consider the noise level because some tumblers are quite loud.
We tested the National Geographic Hobby Rock Tumbler Kit, which is designed with children in mind and reliably produces a large batch of smooth, polished stones in about a month. Our experts recommend a single-drum model to begin with, though a double-drum tumbler is a worthwhile investment if you’re an avid rock collector.
Best rock tumblers
Our top pick works well not only as a first tumbler but also as one you can continue to use if you find that you really enjoy the hobby. The included guide makes it easy to get started, and the four grit packets are enough for your first batch.
The replacement belt drive ensures that you can use your tumbler for several batches, and you can purchase additional grit from the company’s website. You can adjust the speed to account for the type of rocks you’re using and how much polishing they need. It produces round, shiny stones after about a month of continuous use.
The price of this tumbler puts it in the middle of the range, and it’s an excellent value when you consider the included accessories: rocks, four levels of grit, strainer and jewelry fasteners.
This beginner tumbler is easy to use and produces great results after about a month. It includes a few basic tools like jewelry fasteners and strainer, and the guide takes you through the steps to get started. The variety of included stones make for a good first batch, and the operation is simple enough to start tumbling on day one.
The seven-day timer is perfect for checking the stones at the end of each of the four stages. Its 1-pound capacity is large enough for casual rock collectors or jewelry makers. It has a few speed settings and is quieter than similar rotary tumblers.
We like that the rubber drum not only muffles the noise but also makes the drum more durable than plastic models. Hobbyists and kids alike will appreciate this budget tumbler.
With a 3-pound capacity, this tumbler can take on larger batches of stones or coins. It handles a variety of stone sizes well and produces evenly polished stones after four to six weeks. The lack of a timer means you can run the motor as long as you like and not worry about resetting a timer. Rather than using traditional media like plastic or ceramic, Leegol includes a unique walnut-shell media that prevents scratching and can even be reused if you sift it carefully.
We like the rubber-lined drum that’s both durable and quiet, the leakproof design, five additional belts and the lifetime warranty. For its price, it is much larger than other midrange models and works as well for gemstones as it does for jewelry and coins.
Even though “professional” is in the name, this kit works well for beginners. The overall design is sturdy, the controls are simple to operate and the kit includes grit, stones, sifter and jewelry fasteners. The 3-pound capacity can tumble large batches, and the gemstones come in a variety of types, including tiger’s eye, obsidian and amethyst. It features a nine-day timer, three speed settings and a reverse function. Both the motor and drum are quiet enough that you can keep it running in your home. It includes additional belts, and the company is responsive when it comes to replacement parts or issues.
At $60, this is one of the less expensive tumblers available, making it a good gift or starting tumbler for those who are curious about the hobby.
Resembling the original rock tumbler from many 1980s childhoods, this popular compact model is designed for kids. It includes all the accessories needed to get started plus a bag of enough rough stones for two batches. Every bag has a different mix of stones, such as amethyst, quartz and jasper, though your child will likely have no trouble finding stones of their own. This tumbler also comes with a rock identification sheet so your kids can put names to their newly polished stones.
It would be hard to find a less expensive tumbler, and the 1.5-pound capacity is enough for a handful of beach stones. Despite having a plastic barrel, this tumbler produces polished gemstones in about a month, not unlike many of the more expensive models.
This small tumbler stands out for its all-rubber drum, which makes it one of the quieter models available, a major plus if you’re concerned about noise, especially if you have a small home. It includes basic accessories, a pound of rough stones and ceramic media, the last of which many other kits leave out. The base is sturdy and the timer and speed interface are easy to use. Three included belts are enough for the first few batches, and the company offers to ship five additional belts for free. The instruction book is more detailed than most, guiding you through each step with pictures.
Leaks are unlikely with the lid’s rubber seal, so you don’t need to worry about setting the tumbler on various surfaces. If you follow the instructions carefully, it consistently produces shiny polished stones after a few weeks.
Similar to the National Geographic hobby tumbler we tested, this model offers a large capacity, polishing 3 pounds of rocks at a time. The rubber barrel is durable and has a tight-fitting seal that does a good job of preventing leaks. The 3 pounds of rough stones are more than most other tumblers include, and the unique GemFoam media creates a shiny finish and can be reused if you wash the grit off the cubes.
On the slowest setting, this tumbler can produce high-quality polished stones in a little over the usual four weeks. The two included belts are fairly durable and can last through several batches. This is one of the more expensive models on this list, so it makes a good gift for older kids or adults.
One of the only vibratory tumblers that’s readily available, you can tumble up to 4 pounds of rocks and expect a shiny batch of evenly polished stones. If you (or your kids) don’t want to wait a whole month for your first batch of polished stones, this is your best option because it can handle a large batch in about a week.
This tumbler supports both wet and dry operation, and running the tumbler without water can remove tarnish from metals. With no motor band to worry about, this model is likely to outlast most rotary tumblers. It can run constantly and is efficient enough for professional jewelers.
After tightening the bolts, this tumbler is ready to go right out of the box. Its price makes it a model that hobbyists are most likely to appreciate, though it doesn’t cost much more than some smaller capacity rotary tumblers.
How we tested
After researching dozens of tumblers, we compared the functionality and results of the eight tumblers above and gave the National Geographic Hobby Rock Tumbler Kit a spin. We recommend this model for its easy setup and reliable results, even with your first batch.
Getting started
Set up: The included instructions had us tumbling rocks quickly and only included a few steps: fill the tumbler with the provided rocks and grit, add water, then plug in the tumbler and set it to its maximum time of seven days. The longer you tumble the rocks, the better the results.
The process
Noise: Rock tumblers are known for being loud. We found that it’s a good idea to put the tumbler in an accessible place where noise won’t be an issue, such as a garage.
Maintenance: We changed out the grit each week for a month, allowing the rocks to go through all four polishing stages. We checked it daily to ensure it was operating properly and that the belt had not slipped off.
Results
Quality: At the end of the four weeks, the rough, jagged rocks were now much smaller polished rocks, resembling what you might find in a store. To make them extra shiny, we rubbed them with mineral oil.
Jewelry: We used some of the stones to assemble the included pieces of jewelry and a key ring, which were easy to make.
FAQ
Q. What else do I need besides a tumbler and rocks?
A. You’ll need grit to create friction, as well as tumbling media, usually smooth ceramic pellets, to ensure the rocks are polished evenly. You’ll also need a strainer to rinse the rocks, as well as water to add to the tumbler. A respirator and safety glasses are essential for protecting your lungs and eyes.
Q. What are common problems and how can I prevent them?
A. While this isn’t a problem that affects the polishing process, you should never pour the water from a tumbler or water used to clean rocks down the drain — doing so risks causing serious plumbing problems.
“Bruising” on rocks looks like chips, dents or cracks and is the result of the rocks banging into each other with significant force. If this occurs, try adding either more rocks or more media to fill up the tumbler and limit the movement of the rocks.
Rocks that don’t have a shiny polish or have rough or hazy areas can be the result of any or all of the following: not running the tumbler long enough, not adding enough media or not cleaning the drum thoroughly between batches.
Q. What types of rocks can I polish? Can I tumble anything besides rocks?
A. You’ll have to brush up on your Earth science a little. Rocks should be from 5 to 7 on the Mohs scale of hardness, and all rocks in a batch should be of similar hardness. Popular types include rose quartz, tiger’s eye and jasper. You can also polish metal components and coins in a tumbler.
