Have you ever visited a beach and encountered a beautiful rock you wanted to own as your prized possession? Or wanted to add it to your exquisite jewelry collection? Well, this can be done by rock tumbling.
Rock tumbling is a leisure activity involving gathering various rocks and processing them into stunning gemstones that may be used to create jewelry, decorations, or just be enjoyed as a hobby.
What Is Rock Tumbling?
Rock tumbling is a method for polishing and grinding rough rocks. Rock tumbling is done through a rock tumbler, a mechanical device that continuously rotates a barrel for days. Tumblers promote rock, water, grit impact, abrasion, and friction. These procedures transform unpolished, rough rocks into beautifully polished, rounded stones over time using the proper formula and procedures. Rock tumbling is a common hobby carried out on a bigger scale to obtain vast quantities of finely polished stones for sale in the United States and other Western nations.
How Does A Rock Tumbler Work?
Rock tumblers use repetitive impact and friction principles to compress a thousand-year process into a few weeks, all due to the development of simple mechanical instruments.
The motor is the primary part of tumblers. A motor creates a shifting magnetic field using an alternating electric current. The alternating current can cause a gear or a belt to spin, just as you can make a magnet spin on a table by using its opposing magnet. This rotation happens only every few seconds in the case of a rotary tumbler and is conveyed by a belt to a rotating pin, on top of which the barrel sits.
Gears, on the other hand, are employed in vibratory tumblers to adjust the spinning pace. The spinning object is then unevenly weighted, causing the barrel of a vibratory tumbler to bounce back and forth swiftly (or vibrate).
Water and fine grit are poured into the tumbler, rocks, and minerals to create a solution. The water slowly and repeatedly erodes the rock, and the grit adds friction to the mix to accelerate the process.
In a rotary tumbler, as the rocks collide with one another, grit becomes trapped between them, and the smaller bits fall off. If left exposed for a long enough period, each stone will eventually shed little fragments, molding more closely into a spherical.
Rock and grit friction is what vibratory tumblers rely on when rocks don't collide. Due to the frequency of vibration, this is quite effective since it results in 100–1000 more "back and forth motions" than would occur in a rotary tumbler.
3. The Different Stages of Rock Tumbling
Rough rocks that frequently have little intrinsic value are used in a particular tumbling mechanism throughout the procedure. The rocks must have nearly the same rigidity
to avoid damaging one another.
Stage 1 – Shaping Your Stones
The initial stage in the procedure is shaping with coarse grit. Fill the barrel with rocks until it is three-quarters full, and use 60-80 grit material. Fill with water till it slightly reaches the level of the rocks. If you want the shapes of the rocks to be more similar to spheres, tumble for a week or two. Rocks are mostly shaped in this stage by grit and colliding with one another. As a result, your rocks will get rounded and lose their jagged edges.
Stage 2 – Edge-refining With Medium Grit
It should take roughly the same time to complete stage two (the finer grit). Repeat the previous procedure. Use the same rocks from the first stage with 240-400 grit material. Apply the same principle to water. Most edges and corners are taken care of, along with any noticeable scratches, cracks, or pits. When the rocks are dry at this stage, a dim glow is produced on them. Tumble for 4-7 days before moving to the next stage.
Stage 3 – Pre-polishing of Stones
Use 600-800 grit material with the same rocks and water idea as in the previous stages. This is the major smoothing phase and completes the rounding procedure. The goal here is to make your rocks silky smooth and to bring out some shine. This step should also take around a week, although mileage may vary. So tumble for 3-5 days before moving on to the final step.
Stage 4 – Polishing of Stones
Use 1200 grit material, the same rocks, and a little more water. This stage consists of grit that resembles a fine powder. At this point, your rocks should emerge with a brilliant sheen and have an extremely magnificent appearance after another week.
You might want to use some plastic pellets to prevent your rocks from colliding with one another as you polish them. Toss about for up to a week. The stones can be polished in this manner again if necessary.
The last stage is optional but can increase the sparkle of your rocks, particularly if they contain agates and jasper.
It is known as burnishing and is regarded as an additional polishing stage.
The fifth tumbling stage is called burnishing, except this time, you use soap or powdered laundry detergent instead of grit. Your rocks will become even shinier, seem brighter, and any haze or residue from the slurry will be eliminated.
The majority of people will use borax or shaved layers of ivory bar soap. But whatever soap you choose, be sure there have no ingredients that can damage your rocks. Also, remember to include your plastic pellets for added protection.
The ratios are the same as they are in the grit stages. It is advised to use two tablespoons per pound of rock. All you need is 24 hours in a rotary tumble machine during this step. However, the longer, the better!
4. Types of Rock Tumblers
There are two kinds of rock tumblers. Always consider whatever kind you want to buy since it will affect every batch of rocks for tumbling.
The Rotatory Tumbler
The rotary tumbler operates on a basic rotational concept. The barrel is shaped like a real barrel of wine and rolls continuously for days. You place the rough rocks for tumbling in a barrel, which gently spins on the machine. As the barrel rotates, the rocks in it roll, and as they roll, the edges are knocked off, they get rounded, and they are worn smooth. As a result, the rocks created by a rotary tumbler will be rounded.
The Vibratory Tumbler
The vibratory tumbler works by using friction. In the barrel, stones are placed in a stack of sand-like grit. The motor vibrates the barrel at a high frequency, causing each grit particle to brush against a specific stone spot.
Instead of gently revolving, a vibratory tumbler shakes quite quickly. And instead of rolling, the rocks within are scraping against one another. As a result, the stones in the vibratory tumbler do not change shape much. They retain a shape similar to when you first placed them in. Vibratory tumblers may also be used to polish metal items such as coins.
Difference Between the Types
The primary difference between these two types of tumblers is the form of the stone - rotary tumblers can knock a great amount of material off the rocks, making them quite spherical. In contrast, the primary function of a vibratory tumbler is to polish material, resulting in a similar shape to the stone.
Another difference is that rotary tumblers employ many more natural processes and may thus operate at a little slower speed than vibratory tumblers. The same batch of stones may take a week in a rotary tumbler but just 3 to 4 days in a vibratory tumbler.
Categories of Rock Tumblers
Rock tumblers come in a variety of sizes and qualities. Some tumble only a few ounces of stone, while others may process hundreds of pounds in a single load. Some are created to be offered at a low cost. These tumblers may withstand a few batches of rocks but are not intended for long-term usage.
Each of these tumbler categories has a valid market area. They are aimed at consumers with varying spending levels and performance expectations.
Toy Rock Tumblers
Toy tumblers are rock tumblers for kids. They include a plastic base and a tiny plastic barrel holding 1/4 to 1 pound of rocks. When a toy tumbler is turned on, the rocks hitting the interior of the plastic barrel makes a lot of noise.
Toy tumblers are designed to make a child's toy that will sell for a low price. Using a low-cost motor is the greatest approach to saving money while making a tumbler. Many toy tumblers come with a low-cost engine and a low-cost plastic barrel. However, before a few batches of rocks have been polished, the motor, barrel, or drive train component frequently fails.
Beginner's Rock Tumblers
The most common characteristics of beginner's rock tumblers are a plastic base and a tiny rubber barrel. Typically, the barrel is large enough to tumble one or two pounds of stone. Beginners should be aware of the energy costs, noise issues, and alternatives for delicately tumbling stones. However, they make less noise and generate more rocks with a higher polish than the toy rock tumblers.
Hobbyist Rock Tumblers
Hobbyist tumblers are constructed to last for years of consistent or occasional use. They have high-quality metal bases, rubber barrels, and motors.
Many hobbyist tumblers may be used for decades with regular lubrication. Small hobbyist tumblers often feature three-pound barrels, which is plenty for a beginner's tumbler. Larger hobbyist tumblers have barrel capacities of six, twelve, or fifteen pounds.
The majority of vibratory tumblers are made at a hobbyist level of quality. When compared to rotary tumblers, they are more expensive to buy. The customers that purchase them are typically more seasoned and prepared to spend more for a machine of greater caliber. You get what you pay for, but a hobbyist tumbler will cost more than a beginner's tumbler.
Commercial Rock Tumblers
Commercial tumblers are big tumblers that a firm or a person can use to make tumbling stones, polish pre-formed cabochons, clean raw stones before grading, polish ammunition casings, or perform other functions as part of a serious hobby or business.
The weight of the stones in the large barrel of a commercial rock tumbler produces a more aggressive tumbling movement, resulting in a quicker stone processing rate. If you are running these devices, you will need a strong individual to handle the barrels.
A commercial rock tumbler is expensive. A small commercial tumbler will cost a few hundred dollars, while a bigger commercial rock tumbler will cost over a thousand dollars. However, the power and labor costs for the number of stones processed are substantially cheaper than tiny tumblers. People that do this much tumble frequently gather their own rough, purchase rough by the barrel, and get their supplies in large quantities.