Rock tumbling media substitutes

Rock tumbling media substitutes DEFAULT

The Best Rock Tumbler

Best image of rock tumblers

Photo: NATIONAL GEOGRAPHIC Hobby Rock Tumbler Kit - Includes Rough Gemstones, 4 Polishing Grits, Jewelry Fastenings, Learning Guide, Great Stem Science Kit


To help you find the perfect rock tumbler, we continuously put forth the effort to update and expand our list of recommendable rock tumblers. Our team collects, edits and publishes new information, in order to present it to you in an accurate, significant and neatly arranged way.

Buying Guide

Top Rated Rock Tumblers

If you're looking into finding the best rated rock tumbler, you should probable check out the AliKids Thumler s Tumbler. We looked at various sources of reviews and found this one to have the best mix between review count and average rating stars.

AliKids Thumler s Tumbler

The Lowest Price We Could Find

Often, going for the best price is a simple but good option. With a price of $(last checked this morning), we do not list any other rock tumblers cheaper than the Leegol Electric Tumbler. Just remember that it's not always the best option to go for the cheapest one.

Leegol Electric Tumbler

The Rock Tumbler With the Most Reviews

With at least 20 reviews and counting, the AliKids Thumler s Tumbler might be another option to consider. This large amount of reviews signalizes that many people are using it, with most of them beeing satisfied.

High Quality Rock Tumblers

It's quite rare that the saying "You get what you pay for" turns out incorrect. If you have the money on the sideline, feel free to choose the most expensive item from our list: The MJR s MJR Tumblers currently sells for $

MJR s MJR Tumblers

The Rock Tumbler With the Most Clicks

If you trust us and our users, feel free to check out the AliKids Thumler s Tumbler. Our statistics say that it is the most favorite Rock Tumbler from the list above.

Our Bestseller

If you're still undecided, I would recommend that you go with the masses and choose the top selling rock tumbler: The AliKids Thumler s Tumbler is the hottest bestseller in this category right now.

Rock Tumbler Reviews

There are no reviews on rock tumblers, yet.

Be the first to write a review, or check for additional reviews in the Further Reading section below.

Further Reading on Rock Tumblers

New: Our editorial list of additional articles. We decided to gather informartion all around the internet and present you a list of helpful, external links to interesting reads about reviews, pros & cons and similar products.

HARBOR FREIGHT Rock Tumbler (Review): Best Tumbler F

I wanted to do as much research as possible on all of the Harbor Freight Rock Tumblers, and share with you what I found, the pros as well as the cons.

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Rock Tumbling - The Ultimate Beginners Guide to Tumb

Depending on what you're tumbling, there are a few media substitutes you can try including: Ceramic pellets. Aquarium gravel. Marbles. Sand. Walnut shells. Corn cob. Stainless steel bb's. Tile spacers.What is a rock tumbler? - Br

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Thumler's Tumbler - Supplier Of Professional Roc

Supplier Of Vibratory Tumbler, Rock Polisher, Rock Tumbler and Abrasives to hobbiest and professional metal finishers.

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Rockpick Legend Co. Your Complete Rock Experience (T

Do the same thing but each has its own usefulness and their pros and cons. This chart shows the differences comparing quality rock tumblers 

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helpful or not helpful Everything you need for rock tumbli

We are the internet's most popular source of information about rock tumbling. We also sell rock tumblers, tumbling rough, tumbling supplies, and tumbled stones 

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DIY Rock Tumbling Grit Substitute - Rock Seeker

What Is The Best Rock Tumbler Grit? Polly Plastics Rock Tumbler Tumbling Media. National Geographic Grit Refill for Rock Tumbler. Evostrom Polypropylene Plastic Filler Pellets.

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Do you want to know more about rock tumblers? Check out the links below to gain knowledge about the whole topic of rock tumbler products.

Useful Videos

Selecting a Rock Tumbler -

Which rock tumbler is best for you? This short video will introduce you to several different rotary rock tumblers and important features that will help you identify

Disclaimer: This video was not made by us, but we found it interesting enough to embed it here.

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Make Your Own Rock Tumbling Grit Substitute

Rock tumbling is an excellent hobby for both children and adults alike. The beautiful gemstones you create with rock tumbling can be turned into jewelry or just simply displayed in a rock display case for the world to enjoy. 

Unfortunately, getting started in the rock polishing hobby can be cost prohibitive for many people. A good quality rock tumbler can cost you anywhere from $ all the way up to $ In addition, You also need to buy rock tumbling grit to get to the nice polished look you want. For a look at the best rock tumblers that are high quality and reasonably priced, read my review on these rock tumblers.

For those of you that are looking to cut costs, there are options when it comes to finding a rock tumbling grit substitute, so as not to break the bank.

Is There A Good Substitute For Rock Tumbling Grit?

It is possible to make your own rock tumbling grit substitute. It requires a lot of time and work because it is necessary to bring the homemade tumbling medium to an even consistency.  In order obtain that consistency, you need to use screens to filter the material as you go.

The biggest danger in not having an even and consistent tumbling grit is the potential of scratches. Having even one large grain with your finer blend will result in unwanted markings and scratches.

What&#;s Rock Tumbling Grit Made Out Of?

Commercial rock tumbling grit is made out of silicon carbide. This is the best tumbling media or “tumbling grit” for rocks.

The first thing many people consider using when looking for a substitute tumbling grit is sand. The problem with sand is that it is too soft.  Sand generally has a hardness of 7 to of the mohs scale of hardness.  Whereas silicon carbide is significantly harder at 9 to on the mohs scale.

The rocks you are tumbling, like quartz, amethyst and almost all other types of rocks are 7 or above on the mohs scale. You could literally tumble for months and not see any change at all in the way your rocks look.

How to Make Your Own Rock Tumbling Grit

There are people that have experimented with making their own rock tumbling grit substitute. Some of which work fine, and others that do not work at all. The key is to get out there and experiment.

Since it’s difficult to match the hardness of silicon carbide, the biggest downsides to making your own grit is that it will take longer to polish than regular grit as well the potential of unwanted scratches by having grit that’s not consistent.

First Stage/ Rough Grit Substitute

For the first stages of rock tumbling, where more rough grit is required, try these substitutes. Keep in mind that the entire process will take a couple weeks longer than if you were using commercial rock tumbling grit.  And remember to never overfill your tumbler!

  • Silica sand. This can work as a substitute grit. The process will take a couple weeks longer than commercial rock tumbling grit. Silica sand can be found at your local sandblasting company.
  • Sinterblast is an economical brown sintered aluminum oxide blasting grit. Sinterblast is gaining in popularity and is also recyclable. It comes in 30, 36 and 60 grades.
  • Ask a sandblaster near you for other ideas you can use as a rock tumbling medium.

Polishing Stage/ Fine Grit Substitute

A homemade rock tumbling grit substitute mixture you can experiment with is a mixture of flour,sand,salt,and fine crushed rocks.  I’m not sure how well this mixture would work, but I&#;m doubtful it would be very effective.  The only way to find out would be to try it!

Rock Tumbling Plastic Pellet Substitute

During the polishing/finishing stage, try experimenting with these substitutes for plastic pellets. These fillers will protect your stones from scratching each other as they tumble.

  • Cut up rubber bands
  • pea-sized river stones
  • Cornmeal
  • Sawdust or wood shavings

Not Ready To Make Your Own Rock Tumbler Grit?

Not quite ready to tackle making your own rock tumbler grit? That&#;s not a problem.  Below are two of my top choices of tumbling medium you can get, that won&#;t break the bank. Both of these are excellent choices for all levels of rock tumblers.

What Is The Best Rock Tumbler Grit?

1. Polly Plastics Rock Tumbler Tumbling Media

best rock tumbler grit for rock tumblers

2. National Geographic Grit Refill for Rock Tumbler

best rock tumbler grit for rock tumblers and rock polishers

Best Plastic Filler Pellets For Rock Tumblers

Maybe you already have the tumbling grit you need for your rock tumbler, and just need the plastic filler pellets.  If that&#;s the case here is the best plastic filler pellets for rock tumblers that I&#;ve been able to find.

There are lots of plastic filler pellets available, and you would probably do fine with any of them, but the Evostrom Polypropylene plastic filler pellets give you the most pellets for your dollar.

Evostrom Polypropylene Plastic Filler Pellets

best plastic filler pellets for rock tumbler


Like many of you, I don&#;t have a ton of extra money just sitting around that I can spend on my rock collection and rock tumbling hobby.

So for those of you that are like me, I put together a post where I take a close look at the rock tumblers that Harbor Freight make.   The post is called Harbor Freight Rock Tumbler Review: The Best Economical Rock Polisher.  Harbor Freight has come through for me on a pinch more than once.  And they don&#;t fail on me here either!

 Have you experimented with making your own rock tumbling grit substitute? Let us know what worked and what didn&#;t work for you.  Leave a comment below and let us know what we can use as our own DIY grit!

Related Posts:

  1. Where To Find Rough Rocks For Tumbling (And Raw Gemstones For Polishing)
  2. The Best Rock Tumbler Grit
  3. How To Use A Rock Tumbler
  4. Best Rock Tumbler For Beginners: Take Your Hobby To The Next Level
  5. Harbor Freight Rock Tumbler Review: The Best Economical Rock Polisher

DIY rock tumbling grit

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Calling all rock tumblers! Do you feel like you are throwing away perfectly good grit? The price of everything is rising, and tumbling grit is no exception. In an attempt to save money, you may be wondering how to go about doing that. Is reusing tumbler grit the answer?

Rock tumbling for some is a hobby or passion. And, for others, it is a career. Either way, materials can be costly. To save money, some people will reuse their Silicon Carbide grit. While this may seem like a good idea, it ends up costing more and being less effective. Plastic filler pellets can be reused, though.

Let’s get down to the nitty-gritty of rock tumbling. Should we, or shouldn’t we reuse our tumbling grit? That is the question.

If you are interested in checking out the best grits for rock tumbling you can find them by clicking here (Amazon link).

Rock Tumbling Grit

Can Rock Tumbler Grit Be Reused

What people love about rock tumbling is taking something as simple as a rock, and turning it into a shiny piece of art. The great thing about rock tumblers is that they do most of the work for you. The finished product makes great jewelry or display pieces.

Just toss in your rocks, and a few scoops of grit, add some water, and hit the power switch. The rocks are typically purchased as raw or rough stones.

To get them polished and looking pretty, it is going to take some serious scrubbing. That’s where grit and the constant motion come into play.

Grit is a man-made material called Silicon Carbide. This media has been used as an abrasive since Used for things like sandblasting, waterjet cutting, and rock tumbling.

Once the grit has been tumbled around with your batch of rocks for a cycle, it is filled with particles of rock, dirt, and other foreign materials.

Most experienced tumblers would agree that while they would love to reuse the tumbling grit, they won’t do it. It is not worth it to risk it. Reusing grit will not harm your tumbler.

However, it can damage the next batch of rock. Plus, it just isn’t the same consistency as when it is first mixed with water.

Reusing Rock Tumbler Grit

Does it hurt anything if you reuse tumbling grit? It could damage your rocks due to small particles of precious rocks that were left behind. When you reuse rock tumbling grit this is what happens.

While you may be trying to save money or save the planet by reusing grit, what is actually happening is that your tumbler has to work twice as long when it is filled with recycled grit.

So, if we stop to put it into perspective, that is more money spent on electricity. And, also more wear on your machine.

Reusing grit is not a common practice in the rock tumbling community. However, it does happen. So, you may come across experienced tumblers that have been reusing grit for years.

They rinse the slurry off, let the water either evaporate or dump it off. Then, reuse the grit the next time they tumble.

One thing that can be reused is the plastic pellets that are used for filler if you do not have enough rocks to make a full barrel.

Though you can reuse the pellets, they should be used with the same size grit every time to prevent cross-contamination. Rinse them well to prevent grit from hardening onto them. Air-dry the pellets and label them before you pack them away.

Rock Tumbler Grit Substitutes

Looking for a less expensive rock tumbler grit? Or, perhaps a substitute material that is more budget-friendly?

While the thought may have crossed your mind to grab a pound of sand from the sandbox in your backyard to try in your tumbler, you can forget that idea.

The granules all need to be the same size, shape, and type. And, to compare every grain of sand in a one-pound bag is next to impossible.

The only thing that is recommended to use in your tumbler is water and Silicon Carbide grit that is specially designed for tumbling rocks. Not beach sand, nor salt, or kitty litter.

Silicon Carbide is special because the particles are hard enough that they won’t get rounded during tumbling. This may be one reason that people believe grit to be reusable.

Your best bet is to buy in bulk and to shop around. Just because you have found a brand that you like doesn’t mean that you are currently getting the best price that is out there.

Another trick of the trade is to buy a less expensive grit for the first step, and a more premium brand for the polish stages.

TIP: Have you ever think about using sand for tumbling? Well, it is not the best idea but sand can be great as a pre-grit. Read more about this option:

Can You Tumble Rocks with Sand? Everything You Need to Know

Proper Grit Disposal

Do not rinse grit down the drain. As wet grit dries out, it hardens quickly and turns into a cement-like substance. Dried grit will ruin your plumbing, and your day.

The most popular way to dispose of used water, slurry, and grit particles is actually to throw it out the door. Dumping residues in your driveway, garden, or woods behind your house.

Remember this is a man-made substance. And, while many people dump their grit in the driveway or garden, the Silicon Carbide can get eaten by animals or soak into the ground.

Rotary Tumbler vs Vibratory Tumbler

The two main types of rock tumblers are rotary & vibratory. Just by the names, you can probably guess the main difference between the machines.

Can you reuse grit in either of these tumblers?

It is not recommended to reuse grit in either style of the tumbler. However, the vibratory tumbler does use less grit than a rotary tumbler. So, using a vibratory style would cut down on how much grit you buy.

  • Rotary – The more popular/common of the two main types of tumblers. The rotary tumbler uses about 2 TBSP of grit per pound of rock. The tumbling cycle is typically days. Rounds the rocks out.
  • Vibratory – The vibratory tumbler uses about half the amount of grit, and works in less than half the time of a rotary tumbler. Produces high shine, rock does not become rounded but keeps the original shape.

TIP: Do you know you can also tumble your rocks without a tumbler? Yes, you can tumble rocks with your hands. Read more about how to tumble rocks without a tumbler here:

Can You Tumble Rocks Without a Tumbler? Step-by-Step Guide

Top Tips for Using Tumbler Grit

In addition to using fresh grit every tumble, here are a few more tips on how to get the most tumble for your time, effort, and money.

  • You need to keep it separated

For those that use a rotary tumbler, try using separate barrels for the polishing stages. Or, a different barrel for each stage, and each level of grit. This goes for vibratory tumblers, as well.

Using separate barrels eliminates the need to deep clean a single barrel between steps. If you do not clean between steps your rougher grit can carry through to the following stages possibly creating scratches.

It is recommended to tumble the same type of rocks together. Instead of type, you can tumble rocks together that are similar in hardness. Tumbling stones together that are a variety of sizes will give you more friction (in a good way.)

Cleaning rocks between steps is one of the most important parts of rock tumbling.  A water pick works wonderfully for getting into any areas that grit may be stuck.

For those that enjoy the roundedness that you get from a rotary tumbler, but with the process was shorter, here’s your solution. Complete step one using a rotary tumbler to get the rounded effect. Then use a vibratory tumbler to speed up the rest of the steps.

  • You can tumble more than once

Re-tumble rocks as many times as you like. The more you tumble them, the smoother, less pitted, and higher shine they will have.

For a deeper dive into the educational side of rocks, check out this experiment you can try.

The Key Takeaway

Unfortunately, we are really not able to reuse our tumbling grit. However, there are plenty of tips above to help you get more out of rock tumbling. Try out some of these tips to see how they work for you. Happy tumbling!

TIP: When you want to tumble rocks, you need to find some first. Check out where are the best places for finding rocks in the US:

Where to Find Rocks, Minerals & Crystals in the USA


Ceramic Media Can Improve Your Tumbled Stones

Rock tumbling media

This is a small scoop of material from our media bucket. As you can see we have a range of different sizes of ceramic media. We believe that using a range of sizes of media works well for our needs. You probably also noticed some stones. These are small stones that have been through the tumbling process but did not pass our quality test. They work great as media and another trip through the tumbler often improves their quality.

Ceramic media and plastic pellet media are used as a filler or as a cushioning agent in rock tumbling. This video shows how they work for the various applications in a rotary tumbler.


What Is Rock Tumbling Media?

Rock tumbling media is a rounded or cylindrical material added to the tumbler barrel to improve the results of your tumbling. Its rounded shape improves the tumbling action. Its presence between the tumbling stones facilitates abrasion on all surfaces of the stones. The smoother tumbling action helps to prevent chipping and bruising of the tumbled stones.

Ceramic Pellet Media

Most media used in rock tumbling today is a kiln-fired ceramic pellet media that has a hardness of 7+ on the Mohs Hardness Scale and an excellent tenacity. It is extremely durable, reusable, easy to clean, and will last through many batches of tumbled stones. We use ceramic pellet media in all of our rotary and vibratory tumbling.

Plastic Pellet Media

Plastic pellets were the most popular tumbling media from the s through the s. They were used to cushion the stones and reduce bruising caused during tumbling.

Today most people use ceramic media, but some have used plastic pellets for decades and still prefer them for rotary tumbling. Ceramic cylinders smooth the tumbling action and this results in less bruising of the stones. Ceramic media is also hard and more effective at grinding and shaping stones.

When ceramic media was introduced in the early s, most people who tried it stopped using plastic media - because ceramics were more convenient. When using plastic pellets, the pellets can only be used with one size of grit - because tiny particles of grit become embedded within them. When using ceramic pellets, the rock mud and the grit rinse right off of the stones between tumbling steps. Today we sell at least 10 times more ceramic media than plastic media.

Benefits of Using Ceramic Media:

When properly used, ceramic tumbling media can improve your tumbled stones. Here are several benefits from using ceramic cylinder media:

1) Cushioning: To absorb impact energy between the stones in the barrel.

2) Particle Size Balancing: Add small particles to a load of large rocks.

3) Filler: Get the barrel up to operating capacity.

4) Improve Tumbling Action: Make the rocks in the barrel tumble better.

5) Deliver Grit to All Rock Surfaces: Facilitates polishing and grinding.

Now that you understand the benefits of using ceramic tumbling media you still need to determine Which size should you use? How much should you use? Below are recommendations on how you can achieve the benefits listed above.

Quartz tumbled with and without cushioning

The two photos above are of the same piece of rock crystal.

The top image shows the piece after being tumbled without proper cushioning. The stone has numerous chips and bruises. This damage was cause by hard impacts with other stones in the barrel.

The bottom image shows it after being re-tumbled using ceramic media as cushioning. You can see how much less chipping and bruising are on the stone.



Have you ever tumbled a batch of rough only to open the barrel after the polishing step and notice little white fractures or chipping around the edges of your stones?

Those marks on the stone are called "bruises" and they are a result of the stones banging against one another in the tumbler with enough force to cause damage.

Most bruises result from two things:

1) a tumbler that is too fast for the durability of your stones (most tumblers are too fast for almost any type of stone except jasper, agate and other varieties of chalcedony), and,

2) large stones being banged against one another in the tumbler. Cushioning your stones will reduce, and in many cases, eliminate this problem.

How does media provide cushioning and stop your stones from bruising each other? Media in the barrel will keep the stones from hitting one another as often as they do when there is no media. The media will also slow down the stones and reduce the force they have on each other when they do come together.

Think of a child jumping into a ball pit like we used to see at McDonald's. If there were no balls in the pit the child would have a high energy impact with the floor. However, with the balls in the pit there is no high energy impact.

The initial energy from his fall starts to be absorbed by the first balls his body touches. That energy is then transferred with less force to all of the balls that they touch. Then with even less force the energy is transferred to all of the balls that they touch. This continues until all of the energy has been absorbed through less and less forceful impacts between the balls.

All of this energy absorption keeps the child from hitting the floor or if they do hit the floor it is with very little force. Using ceramic media in the barrel can have the same effect on the rocks in the barrel.

What Types of Rocks Need Cushioning?

Two types of materials require cushioning:

1) those that bruise or chip easily; and,

2) those that break easily by cleavage.

Materials that bruise or chip easily include: obsidian, glass and crystalline quartz. (Banded amethyst, rose quartz, rock crystal, aventurine, and tiger's eye are common varieties of crystalline quartz.) These materials can be chipped or bruised by impacting with one another in the barrel. Adding media for cushioning can reduce this damage.

Materials that cleave easily include: fluorite, topaz, moonstone, amazonite, labradorite and orthoclase. Many people avoid tumbling these materials because they are difficult to tumble with good results. Adding media for cushioning can solve that problem.

We use at least 50% media in the barrel to properly cushion fragile tumbling rough. Small ceramic media works best to cushion the material. We usually use a mix of large and small media for cushioning because it also helps with particle size balancing.

Particle size balancing with ceramic media

The top illustration shows how much empty space there can be in a barrel of large rough. It also shows there are not many contact points between the rough. Grinding and smoothing occurs when grit is caught between these points of contact. If you increase the number of contact points, more smoothing and grinding will occur.

The bottom illustration shows how media can fill the spaces between the stones. Filling in those spaces also creates many more contact points on the rough. The stones in the bottom illustration will shape much faster and are less likely to chip or bruise.

Particle Size Balancing:

What is particle size balancing? Particle size balancing is making sure that you have a range of different sized material in the barrel. If the rough in the barrel are all large pieces there won't be many points of rock to rock contact as they tumble. Grit does its job when it is caught between the stones and the media. The pressure of that contact enables the particles of grit to abrade and smooth the stones.

Imagine bowling balls in a box, there are only a few points where they touch each other. Now if you put some golf balls in that box you have significantly increased the number of contact points on the bowling balls and filled much of the empty space between them. Adding marbles would fill in even more of the empty spaces in the box and maximize the points of contact against the bowling balls. This shows how using a range of particle sizes in the barrel increases the number of contact points where the shaping and smoothing of the stone occurs.

The best way to get a balanced load in the barrel is by using a range of smaller pieces of rough. If you don't have smaller pieces of rough ceramic media should be used. If you are using ceramic media for the first time we suggest getting both small and large because having a range of sizes in the barrel works best.

Improve Tumbling Action in the Barrel:

If you have rough with lots of flat pieces (such as trim-saw slabs) or lots of very angular pieces, they might slide in the barrel instead of tumbling. Adding ceramic cylinders will help get those stones tumbling. Ceramic cylinders act like roller bearings in the tumbler barrel. They get between flat and angular pieces of rough and increase their motion. A mix of ceramic media sizes works best.


Large ceramic tumbling media

Unused large ceramic media ready to be used as filler. Notice how it has sharp edges. Do not use band new media in the fine and polish steps. The sharp edges will scratch your stones. We introduce new media in the coarse grit or medium grit step and then it is ready when the fine grit and polishing steps arrive.

The most important use of ceramic media as filler is in replacing the volume of rock lost during the coarse and medium grit steps of the tumbling process.

During the coarse grit step between 10% and 30% of the rock volume in your barrel is lost to grinding. It is worn away and becomes the rock mud that you see in the barrel after tumbling a batch of rocks.

To maintain a good tumbling action and to keep your barrel up to the recommended tumbling volume of about 2/3 full, adding ceramic media is recommended. We add enough ceramic media to bring the barrel up to about 2/3 full.

Less rock volume is lost during the medium grit step, but it is still important to add ceramic media to keep your barrel at the recommended tumbling level.

Replacement of rock volume with ceramic media is important in both rotary and vibratory tumblers. The ceramic media helps give your rocks a smoother ride during the fine grit and polishing steps. Without the addition of media, the rocks will receive a rougher ride that might cause chipping and bruising.

Magnesite after coarse grit

The photo above shows what happens to rough during the coarse grit step using different amounts of media. The two stones on top were tumbled for one week in a barrel that contained a little over 50% ceramic media. The stones on the bottom were tumbled in a barrel with all similar size rough and no media for one week. Notice the stones on the bottom are more rounded.

(In the past, we used to recommend the use of ceramic media during the coarse grit step of rotary tumbling if you did not have enough rough to fill the barrel up to its recommended operating capacity. We have found through testing that better-shaped stones are produced during the coarse grit step in a rotary tumbler when only about 10% of the load (by volume) is ceramic media. Too much media can prevent the stones from aggressively wearing away the points and edges of one another.

The only situations where we would use more than about 10% media during the coarse grit step of rotary tumbling are: (A) when we have a barrel full of large material with nothing filling the spaces between the rocks, then we might use up to about 20% media to improve the tumbling action; and, (B) when the rocks already have a nicely rounded shape and only surface smoothing is needed.)
Our media bucket

Here is a look into our media bucket. You can see a range of ceramic media sizes in the bucket as well as some small stones that have already been tumbled at least once. We scoop out of this bucket every time we start a new batch of stones.

How Long Will Ceramic Media Last?

Ceramic tumbler media has a hardness of about 7+. It is harder than almost all of the most commonly tumbled rocks such as agate and jasper. Small media will last a few tumbling cycles when used in all steps of the tumbling process. Large ceramic media will last much longer and eventually turn into small media.

How Do We Use Media?

We use between 10% and 50% ceramic cylinder media every time we run a tumbler. We believe that a mix of large and small media works best. Tiny tumbled stones also enter into our media plan.

After each batch of rocks is tumbled, we separate media from tumbled stones using a classifier. The tumbled stones do not pass through the classifier, but all media and a small number of tiny tumbled stones fall through into Our Media Bucket. This bucket always contains polished media in a range of sizes ready for use in tumbling. We keep it supplied by frequently adding a small amount of new large media to the coarse grit step of each batch of rocks that we tumble.

If you do a lot of tumbling or simply want to save time, we suggest that you read Our Media Bucket article.

Breaking in New Media

Brand-new media will have some surface roughness that remains after the manufacturing process. If you look closely at brand-new media, you will see roughness around the ends of the pieces. If you add brand-new media to a batch of rocks during the coarse or medium grit step, there is no need to worry about this roughness. It will be smoothed during your normal tumbling.

However, adding brand-new media to a batch of rocks at the beginning of the fine grit or polishing step might produce scratches on your stones. When adding media at this point in the process, it should be media that has been previously tumbled and all edge roughness removed. Preferably, it should be media that was polished in a previous batch of rocks. If you don't have that, simply run the media for a few days in medium grit, followed by a few days in fine grit, and it will be ready to use.
Plastic pellets

Plastic pellets are most often used to cushion stones during the fine grit and polish steps of the tumbling process.

Plastic Pellets:

Plastic pellets have a long history of use for cushioning in rotary tumblers and many people still use them. They are not recommended for use in vibratory tumblers.

We stopped using plastic pellets years ago after we tried ceramic media. We found that ceramic media are just as effective as plastic for cushioning. Here are a few other reasons why we switched to ceramic media for all of our tumbling.

Plastic pellets

1) Are difficult to separate and gather after rinsing.

2) Are tough to get clean and dry before storing.

3) Cannot be reused in a finer grit stage because grit can imbed in them and contaminate the next steps.

4) Must be stored in separate containers according to the grit they were used in.

5) Do not help much with grinding because they are soft.

Not All Ceramic Media Works in Rock Tumbling

Ceramic media is sold for a wide variety of purposes and most of it has embedded abrasive granules. If you use ceramic media with embedded abrasive granules during the polish step they will scratch the stones and ruin your polish. All of the ceramic media that we sell is smooth and does not contain any abrasives.

If you are going to buy ceramic media you need to either really know what you are doing, or only purchase ceramic media from a rock tumbling site that tests their products before they sell them. We test everything that we sell ourselves - and we use the ceramic media that we sell every day in our own tumbling.

Happy Tumbling! Authors

Hobart KingHobart M. King has decades of rock tumbling experience and writes most of the articles on He has a PhD in geology and is a GIA graduate gemologist. He also writes the articles about rocks, minerals and gems on

Substitutes rock tumbling media

Tips on Rock Tumbling Polish Substitutions

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.

Economical Substitutes

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.

Natural Products

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.

Polishing Filler

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.


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Can I Use Sand Instead of Rock Tumbler Grit?

Some people write to us asking if they can use beach sand in a rock tumbler instead of buying rock tumbler grit. This sounds like a reasonable idea because sand is the abrasive material present when rocks are naturally tumbled in a stream or at a beach. However, you will probably be disappointed by its performance in a rock tumbler for three reasons

using sand instead of grit
Rock Tumbler Rough

Jasper, agate, petrified wood, and varieties of quartz are the most commonly tumbled materials. They have a Mohs Scale hardness of 7 - the same as the typical beach or river sand. Because their hardnesses are equal, beach sand is an ineffective grit, compared to silicon carbide which has a Mohs hardness of 9+.

1) Hardness

Most natural sands are composed of quartz, which has a Mohs Scale hardness of 7. This is the same hardness as common tumbling roughs such as agate, jasper, quartz, petrified wood, aventurine, and tiger's-eye. When two materials have the same hardness they are not very effective at cutting one another.


However, silicon carbide grit has a Mohs hardness of 9+ and is a much more effective abrasive. You could use sand as an abrasive for tumbling agate and jasper and it would work; however, the amount of time required to get good results would test your patience.

2) Grain Shape

Most natural sands have round grains; however, silicon carbide grit particles are angular in shape. This angular shape makes them more effective at producing abrasion that smooths and rounds tumbling rough into nice polished stones. Again, you could use sand, but it would take a lot more time to produce results.

3) Electricity Cost

Most people interested in using sand instead of tumbling grit are looking for a cost savings. They see the cost of grit at a few dollars per pound and compare that to free sand that can be gathered at a beach.

However, the total cost of tumbling includes electricity. A small tumbler like the Thumler's A-R1 uses about ten cents worth of electricity per day. The cost of coarse grit needed to charge it is about $ So, running the tumbler for seven days with coarse grit would have a total cost of $ plus one week of wear and tear on the machine.

If you had to run that tumbler for three weeks to make up for the lower hardness of sand and the less effective grain shape your electricity cost would be $ plus three weeks of wear and tear on the machine.


Substituting sand for rock tumbler grit will not save money. Instead it will probably cost more time and electricity than the savings of grit that you achieve. It most likely will produce lower quality results.

The only exception might be when tumbling very soft materials such as obsidian, marble, fluorite and calcite. Sand might work fine with these if you can find sand of the proper particle size. We also know that some people use sand to place a frosted finish on tumbled glass.

For more information about the costs of rock tumbling please see our article: How Much Does it Cost to Run a Rock Tumbler?

Happy Tumbling! Authors

Hobart KingHobart M. King has decades of rock tumbling experience and writes most of the articles on He has a PhD in geology and is a GIA graduate gemologist. He also writes the articles about rocks, minerals and gems on

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