How to Tumble Rocks? [Methods + Safety Tips]

Rock tumbling is the process of polishing and smoothing the rough surface of rocks. Once polished, these attractive rocks can be used either as decorative pieces in homes or as jewelry.

As the name suggests, rock tumbling is done by a rock tumbler and works on the same principle as barrelling. The purpose of spinning these rocks is to make their outer surface smooth and make them beautiful.

If you ever had the chance to visit a river and found some beautiful stones of different colors. Rock tumbling follows the same principle, but is much faster. For a rock to be turned smooth and stunningly beautiful, it takes years of rolling around in the water, but with a rock tumble, you can get the same results in weeks.

What is a Rock Tumbler?

A rock tumbler is a device used to smooth the outer surface of the rocks by rotating them. A rock tumbler is small in size and has a barrel with grit in it, and this grit makes the stones smooth. The grit in the barrel acts as a substitute for natural sand in the rivers.

The grit also comes in different levels of coarseness, like sanding paper. The rock tumbler is very simple to use and has a small size, so you don’t need a ton of space to store it. It is advised to use a high coarse level grit for the first turning to knock out the sharp edges of the rocks.

After a couple of weeks, remove the previous grit and switch to a finer grit. Repeat this process for as long as the stone turns smooth.

Pro Tip:

To reach the final result, you most likely will need a fine power like grit.

Below is an in-depth article about rock tumblers and how you can surprise your friends and family by using them.

How many types does a Rock Tumbler have?

When it comes to the types of rock tumblers, they are divided into two types.

Rotating Rock Tumblers:

Rotating rock tumblers are the most common type of tumblers; in fact, when most people think about rock tumblers, they are thinking about rotating tumblers.

The basic principle behind these tumblers is the rotation motion of rockets to grind against each other and knock off all the sharp edges. The rocks grind against each other to form a perfectly smooth surface and bring out the inner colors and patterns of the rock.

It consists of a rotating drum made of rubber.
A rotating shaft.
A motor.

Vibrating Rock Tumblers:

Vibrating rock tumblers are not that common and are only used to fine polish already polished rocks. Unlike rotating tumblers, vibrating tumblers are not used to shape rocks. If you only want to polish rocks and don’t want to lose their shape, then a vibrating rock tumbler should be your choice.

The main advantage of a vibrating tumbler over a rotating rock tumbler is the high speed. In fact, steps 2 to 4 can all be achieved in 7 days, unlike a rotating rock tumbler that takes seven days for each step.

The downside to vibrating rock tumblers is that they are noisy.

How to use a Rock Tumbler properly?

When it comes to using a rock tumbler, there are three types of smoothing material used, and each has its own separate preparation and usage methods.

Below are the three types of rock tumbling methods and how to properly perform them.

1. Ceramic Cylinder method:

Following are the steps you need to do in order to tumble rocks easily using a ceramic cylinder.

Load the stones into the barrel of the rock tumbler.
Now fill the barrel with a ceramic cylinder to the advised level by the tumbler you are using. (mostly ¾ full is recommended)
The ceramic used helps in improving the tumbling process, and most of all, they act as a cushion, so the process is less noisy.
The ceramic can be reused as well. Make sure to wash them thoroughly before you reuse them.
Remember to only reuse a ceramic in the initial steps for knocking off the sharp edges.
For more delicate smoothing, use new ceramic and rotate the stones for another full week for good results.

2. Plastic Pellets Method:

The second method used for smoothing rocks in a tumbler is by using plastic pellets. Below we have listed all the steps involved in the turning process.

The first step is the same for all the methods: loading the stones in the barrel of the tumbler.
Now fill the remaining space in the barrel with plastic pellets up to the recommended level. (usually, the recommended level is ¾ full)
Just like ceramic cylinders, the plastic pellets work the same and act as a cushion for the rocks. This makes the process of tumbling quieter, improving the process, and gives better results.
Unlike ceramic cylinders, plastic pellets can not really be cleaned once used. It is recommended to use a new set of plastic pellets for each grit size.
However, the plastic pellets can be reused for the same grit number because the pellets adjust themselves for that particular grit size.

3. Grit Method of Rock Tumbling:

The first step is to select the rocks for tumbling and make sure that they are of the same hardness.
Use different size rocks for better results.
Now clean the barrel with water to avoid any unnecessary material getting into the barrel.
Fill the barrel about ⅔ of the way with rocks. (If you do not have enough rocks, fill the rest with ceramic cylinder or plastic pellets.
Now add two tablespoons of 60 grit per pound of rock. (for example, you will need four tablespoons for 2 pounds of rocks)
Lastly, fill the barrel with water and seal it shut. Now spin the barrel for one week.
After the first seven days, reopen the tumbler and rinse the rocks with water. (remember not to throw the waste down your drain; it might cause problems later on)
After cleaning the stones and removing any broken parts, clean the barrel for the next round. Refill the barrel with rocks, and in this step, use two tablespoons of 180/220 grit per pound and run the tumbler for another seven days.
After seven days, reopen the barrel and rinse the rocks once again. Remove any broken pieces as well as ceramic cylinders or plastic pellets if used.
Now the medium grit is done, we have to start with the fine grit. Add the rocks to the cleaned tumbler and add one tablespoon of 500 grit media per pound. Add plastic pellets or ceramic cylinders if required.
Fill the barrel with water and spit for another seven days. After seven days, rinse the rocks and remove any unwanted material like broken pieces of rocks.
For the final polish, clean the barrel once again and add the rocks to it.
Now for every pound of rocks, add one tablespoon of Aluminium Oxide polish to the barrel.
You will need to add plastic pellets or ceramic cylinders to the barrels, as many rocks have lost a lot of outer layers and some broken parts.
Fill the barrel with water and turn on the tumbler. Run it for another seven days.

Now, after seven days, the rocks should be clean and have a smooth and shiny surface. If there are scratches on the stones, repeat steps 2 to 4 to get perfect results. If the surface of the stones is not bright but dull, then add the stones to the tumbler and water.

Then add ½ tablespoon of Ivory soap slice for every pound of rocks. Turn them for several days but check them periodically to make sure that they do not tumble needlessly. You can keep track of your tumbling process by recording the process.

Record data like the type of rocks tumbled, grit type and amount used, the time it took to tumble the rocks, etc.

Safety Precautions for Grit Method Of Tumbling Rocks:

The first two methods are really simple and easy to do as compared to the grit method. They do not require any special preparations and precautions in particular. On the other hand, tumbling with a grit method can be a bit dangerous, so follow the below precautions to the letter.

Keep the tumbler out of range of children.
Wear a protective respirator mask so as not to inhale any fine dust.
Do the same for eyes and wear glasses.
In case any fine dust gets into your eye, wash them with water thoroughly.
Make sure to close the lid properly to avoid it opening during the spinning process.
Wear gloves to protect your hands from any potential sharp objects.

What types of Rocks can be Tumbled:

Many rocks do not perform well in a rock tumbler, and very few types of rocks can successfully be turned by using a rock tumbler. Rocks that can easily be tumbled include.

Chalcedony
Petrified Wood
Jasper
Agate

To put it simply, rocks made of microcrystalline Quartz are good when it comes to tumbling. They are tough, very hard, and durable when polished; these rocks form a beautiful surface.