A rock tumbler is a machine that is mainly used to turn rough rocks into beautifully smooth and polished stones, they are used by lapidary hobbyists, crafts enthusiasts, artists and jewellery makers all around the world.
The process of rock tumbling basically mimics the effect of the ocean on the pebbles that you can find on any beach; the ebb and flow of the tide, along with the sand and other pebbles and rocks, cause friction, abrasion and erosion. This, over time, results in those smoothly rounded pebbles that everyone loves to gather, a rock tumbler works in the same way, only it does its work much faster.
What is the purpose of a rock tumbler?
As previously mentioned, rock tumblers are mostly used for rounding, smoothing and polishing rough rocks, however, they can also be used for polishing metal objects, such as metal parts or metal items of jewellery. Some people even tumble ceramic or pottery pieces, even small pieces of glass can be tumbled in a rock tumbler. Rock tumbling is also carried out on an industrial scale, large hoppers are used to remove burrs from metal parts, these large types of tumblers are also used to polish large volumes of stones for the retail market.
Do rock tumblers really work?
Oh yes, they absolutely do work! These wonderful machines are enormously popular, with many people beginning their journey into rock tumbling (also known as lapidary) at a young age and continuing long into their senior years. There are businesses around the world that are based upon the use of rock tumblers, generally on an industrial scale of course, but this proves that these simple machines do work and work very well indeed!
A brief history of rock tumblers
We already know that the ocean was the first rock tumbler, the beauty of the pebbles was noticed and admired by early civilizations and they sought to replicate it. It is known that slaves were used to operate primitive rock tumblers in ancient Egypt, they sloshed troughs of rocks, water and sand backwards and forwards, emulating the motion of the tide. Jars that were part filled with rocks, water and sand were rolled back and forth in India to achieve the same results. Most rock polishing in those times was done by hand, using tools to chip away at the rock until it was the desired shape, followed by many, many hours of laborious polishing.
It wasn’t until the twentieth century that the type of rock tumbler we all recognize was invented, this came about at some point in the 1950’s, when a jeweler named Edward Swoboda teamed up with a Mr Warren Jones in order to create a machine that would polish rocks to make semi-precious gem stones that he could sell in his jewelry store. When he saw how successful the rock tumbling machine was at generating beautiful semi-precious gem stones, a gentleman named Herb Walters decided that he could do the same thing, only on a much larger scale. He built a business called Craftstones and sold the gem stones to crafts enthusiasts and people who wanted to make jewelry, Craftstones is now an international business.
From those early pioneers of rock tumblers, these amazing machines are now used all around the globe, their popularity ebbs and flows, just like the tides of the original rock tumbler, the ocean.
Types of rock tumblers
There are two main types of rock tumblers that are generally used by rock tumbling hobbyists in the US, the most popular being the rotary rock tumbler, this is the machine that most people start out with when they begin their journey into this fascinating and absorbing pastime. The other type of rock tumbler is the vibratory rock tumbler, this machine is faster but more expensive. Some people choose to have both types of rock tumbler, they shape the rocks using the rotary rock tumbler and then switch to the vibratory rock tumbler for the smoothing and polishing stages, this can save a substantial amount of tumbling time. It should be noted that rotary rock tumblers produce rounded stones and vibratory rock tumblers produce angular stones.
The rotary rock tumbler
The rotary rock tumbler consists of an electric motor set in a metal frame, the motor turns a barrel, which is generally made of plastic or rubber. Once the mixture of rough rocks, known as rough, grit and water have been sealed inside the barrel and the tumbler is set in motion, the motor will keep the barrel turning all day and night until the desired results are achieved. Rotary rock tumblers are also available with a pair of separate barrels, this double barrel version is much more flexible, allowing the user to tumble twice the amount of rocks, it also means that you can tumble rocks of a different hardness at the same time, double barrelled rotary rock tumblers save on energy costs so you will recoup the extra upfront cost over time.
The vibratory rock tumbler
The vibratory rock tumbler has an electric motor set into a stand that holds a bowl – or hopper, into which the rough rocks, grit and water have been sealed, this bowl is generally made of rubber, heavy duty plastic or metal. Once started up, the vibratory rock tumbler vibrates (or shakes) the bowl which causes the friction, abrasion and erosion process, resulting in beautifully smoothed and polished stones.
Both the rotary and vibratory rock tumblers are available in a range of sizes, with the larger, more powerful options being more expensive. Rock tumblers at the cheaper end of the price range will generally be smaller with plastic components, these are usually marketed towards children, however, it is recommended that prospective buyers avoid the lowest priced tumblers as it is likely they will not last very long. It should also be noted that plastic barrels and bowls will make a great deal more noise than the more expensive rubber versions.
Is rock tumbling suitable for children?
Rock tumbling is a great pastime for children, it is not only an educational hobby, it will also teach them patience as they wait for the rock tumbler to do its work and reveal the beauty of the stones. This can be a wonderful hobby for the whole family to enjoy together, from taking trips in the great outdoors to search for rough rocks to tumble, to making gifts from the stunning polished stones that emerge from the rock tumbler following the tumbling process.
Conclusion
We hope you have found this article informative, particularly if you are undecided about taking up rock tumbling as a pastime, it is an extremely pleasant and absorbing way to spend your leisure time, however, you should be aware that rock tumbling can be addictive – in the nicest possible way of course.