How to Tumble Rocks?

Have you ever admired someone's rock collection and wondered how they managed to get such stunning gemstones? You can make your rocks appear just as good by the process of rock tumbling.

Rock tumbling enhances the beauty and attractiveness of tiny rocks, so they may be utilized in jewelry and other home décor items by smoothing and polishing their rough surfaces. Tumbling rocks work on the same basis as barreling metal. Its primary purpose is to polish rocks and bring forth their inherent beauty.

Tumbling rocks can be done with your hands or with a tumbling device. However, a rock tumbling device can efficiently tumble your rocks to produce stunning and well-shaped jewels.

Why Tumble Rocks?

Rock tumbling is more than a hobby. Some individuals tumble rocks for profit to sell them at gem shows and other similar events.

Some of the exciting rock tumbler ideas that might have you rock tumbling include:

  • Unique jewelry making
  • Home decorations
  • Planter/vase filler
  • Key chains
  • Natural magnets & Paperweights

Tools and Equipment for Rock Tumbling

Various tools, equipment, and supplies are required to begin rock tumbling. The following are some of the greatest tumbling gear and equipment to use:

The Rock Tumbler

This is a simple device used to tumble rough rocks. It repeatedly spins a barrel full of rocks, grit, and water for several weeks until the rocks are polished and smooth. Rock tumbler has a barrel that you load with rocks to tumble.

You also fill the barrel with water and grit. Water is a lubricant for the process, and grit is used as sandpaper to scrape and smooth out the rocks.

There are two types of rock tumblers on the market: 'The Rotary Rock Tumbler and 'The Vibratory Rock Tumbler’. 

The most popular tumbler on the market is the rotary rock tumbler. This is because it is designed to smooth out your rough rocks and knock off edges to give a proper shape to your rocks.

A vibratory rock tumbler is significantly more uncommon. It is mostly used for polishing rocks that rotary tumblers have already worked on. As a result, it is only utilized by people who wish to make professional-grade tumblers. This type of tumbler should be used if you merely want to polish your rocks rather than alter their shape. The major benefit of a vibratory rock tumbler is that it accelerates the rock tumbling process.

You'll need equipment to tumble your rocks along with the tumbling machine. The basic equipment includes:


Rock tumbler operators are continuously interested in tumbling new sorts of rocks. They like the thrill of opening the barrel after the polishing process to see what they have made.

The rock tumbler works well with some types of rock. However, not all rocks work well in a rock tumbler.

If you mix fine tumbling rough with below-tumbling-grade rock, the particles, sharp edges, and breaking of the below-tumbling-grade rock would most likely damage the polish on every rock in the barrel. So, choose your rocks for tumbling carefully. The quality of your tumbling stones depends on what you put in the barrel.

Some of the most durable rocks are:

  • Jasper
  • Agate
  • Quartz
  • Obsidian



Grit is a material that rubs against your rocks when tumbling, removing rough edges and smoothing them to obtain the desired result. Grits are classified into four coarseness levels:

  • The Course 60/90 Silicon Carbide Grit

This is the coarsest grit in the rock tumbling process. It is meant for the initial shaping and grinding of rough rocks.

  • The Fine 150/220 Silicon Carbide Grit

This grit is used in the second phase of rock tumbling. It is meant for smoothing the surface of your rocks after the initial shaping is done.

  • The Fine 500F Pre-polish Grit 

This grit is used in the third phase of rock tumbling. It is much finer and is used for the final smoothing of rocks.

  • 1200 Aluminum Oxide Polish Grit 

This flour-like grit is used in the last polishing stage of the rock tumbling process.

Plastic pellets

You might also require plastic pellets in addition to grit. When you do not have enough rocks to fill your barrel, you'll need to load it with these plastic pellets so you can tumble your rocks.

You will have to wait much longer to collect enough rocks without the pellets. Even if you have enough rocks, the tumbling process reduces their size by cutting them. You'll find that the barrel of your rock tumbler cannot be filled with rocks for polishing. The plastic pellets come in help in this situation to fill up the extra space in the barrel so you may polish your rocks.

Plastic pellets do more than just occupy space; they also reduce the force that rocks exert on your rock tumbler and accelerate the process by preventing smooth stones from sliding around. You don't need to purchase a lot of plastic pellets because they may be reused. It should be noted that they are exclusively designed for use in rotary rock tumblers.

How to Use Rock Tumblers?

Although the method of rock tumbling is very simple, there are some steps and stages involved. To guarantee that you obtain the greatest outcomes, you must complete each step.

Before proceeding to the main steps of rock tumbling, certain precautionary measures must be taken:

Inspecting Your Rough

  • The first step in rock tumbling, regardless of whether you buy your rocks or gather them from nature, is to check your rocks for tumbling. Keep in mind that high-quality finished stones are produced from high-quality raw materials. You should thoroughly inspect your rocks and get rid of those that are of low quality.
  • To begin, look for porous rocks. Take out and throw away such pieces. Large solid rocks may have porous portions attached to them. For optimal tumbling, clean such components and remove the porous areas.
  • Next, look for fractures in your rocks so you can deal with any broken pieces. Most fractured rocks will often break apart while tumbling, resulting in not only badly tumbled stones but also scratching the other rocks in the mix and degrading their quality. Throw away tiny, cracked rocks.
  • Sort your rocks according to their softness as well. If you have a variety of rocks, it is critical that you only tumble those with the same overall hardness together. Tumbling both hard and relatively soft rocks together will result in the softer rocks wearing out quicker than the hard rocks, and you may even grind away the softer rocks before the tougher rocks are completed.
  • Finally, measure the dimensions of your rocks. You should not bother about the size of your rocks are all little and around the same size. However, size becomes very important to you if you have both big and little rocks. To uniformly shape the huge boulders during tumbling, little rocks must be placed between the larger rocks. Be careful to load the barrel with big and little rocks for a smooth tumble.

 Loading the Tumbler Barrel

  • This is a further crucial phase to which you should pay close attention. Make sure the barrel is completely clean before loading it. Check for and eliminate any grit or rock fragments left over from the last tumble. The barrel's rim and lid should be cleaned to remove any debris that might lead to leaks.
  • After cleaning the barrel, fill it about two-thirds of the way with the appropriate-sized rocks. Using synthetic materials, such as plastic pellets, if you don't have sufficient rocks to fill the barrel by two-thirds. This is crucial because if the barrel is too small, the rocks will be thrown around and might damage the barrel. Start to tumble after adding grit and water.


After taking these precautionary measures, you may begin with the 4 steps of the rock tumbling procedure.

  1. Coarse Grinding 
  • This is the initial phase in the tumbling process. Ensure the barrel is 2/3 full of rough rocks before beginning the procedure. Add roughly two tablespoons level coarse grit for every pound of rock in the barrel, and then cover with water. Now, lock your barrel and spin the tumbling machine for seven days.
  • After seven days, turn the machine off and open the barrel. Your rocks will be coated with muddy water. Wash and empty the barrel. Also, wash the rocks to uncover beautifully tumbled rocks. Before proceeding to the following step, clean the rocks well to eliminate all grits and small rock fragments.

Several rocks may frequently break while tumbling, and while they appear to be properly tumbled, the crack may reduce their quality. Check for rocks that still need to be ground so you may go through the procedure again. Some rocks might not be ready for the next phase; return them to the course grinding process for another week till they are further rounded.


  1. Medium Grinding 
  • After cleaning and examining your rocks, you may go to the phase with those ready for the procedure. Fill the barrel to 2/3 with rocks. Artificial materials such as plastic pallets can be used if you don't have enough rocks.
  • Once you've filled a clean barrel to 2/3 with clean rocks, add two tablespoons of medium grit of 150/220 silicon carbide for every pound of rock in the barrel. Add water until the water line is level with the top rock surface. Turn on your tumbler machine and tumble for another seven days.
  • After seven days, turn the machine off and empty the barrel. Now clean the barrel and the rocks in preparation for the next stage. The tumbling rocks should now have a smooth surface. Inspect your rocks for cracks so they may be discarded, and those that need to go through the procedure must be placed in the correct group of rocks.


  1. Fine Grinding
  • This is the third step for rock tumbling. Approximately two-thirds of a clean barrel should be filled with clean rocks from the previous step. Water and fine grit should be added in the proper amounts. Run the tumbler for an additional seven days. Stop the machine after the seventh day, and then unlock the barrel to reveal the rocks.
  • Empty the barrels and carefully wash them. Wash your rocks to eliminate any remaining grit and muddy residue. Examine the rocks and discard those that are fractured or have cracks. Also, inspect the rocks to confirm that they are smooth and have begun to shine. Remove any rocks you think are not ready for polishing and add them with those going through the fine-grinding process.


  1. Polishing

This is the final step of rock tumbling. Fill a clean barrel halfway with smooth tumbling stones, then add two levels of 1200 Aluminum Oxide Polish, followed by water to just below the rock level. Start the tumbling machine and leave it running for a week.

Stop the machine after a week, and then take your rocks out of the barrel. The enjoyable part is now! Observe your beautiful stones.


  • Burnishing

This is a completely optional step. Consider burnishing your tumbling rocks if they appear hazy. This is a simple method for cleaning and polishing your rocks by tumbling them in water with detergent for a few hours. To burnish your rocks, place them in your polishing barrel and add water and your preferred detergent. Tumble your rocks for a few hours, remove them from the barrel and let them dry.


Golden Tips for Successful Rock Tumbling

  1. Buy the Right Grid

Grit is made from various materials and in different forms for different tumbling machines. Therefore, you must read the user manuals of your tumbling machines to buy the right grit for them.

  1. Avoid Contamination

To ensure no contamination, clean the barrel, its cover, and the rocks before beginning the tumbling process. If additional coarse grit or other material enters the next step of tumbling, the quality of the tumbled rocks will suffer. Other issues caused by dirt include leaks during the tumble.

  1. Maintain Your Tumbling Machine

Your tumble machine is anticipated to work 24 hours a day, seven days a week, for several weeks. If it is not in great shape before you begin, it will likely break down halfway through the tumble. This will most certainly cause you a great deal of inconvenience. Keep your tumbler in good condition by following the manufacturer's instructions.


  1. Be Patient

The finest outcomes take a long time to achieve. It may be tempting to use shortcuts to speed up the procedure. This will have a negative impact on your performance. To obtain the finest-tumbled stones, be patient and take one step at a time.


  1. Mind the Noise

Tumbling machines could be extremely loud. As a result, it is advised that you store it in the basement to avoid disturbing your neighbors or your family members.