Kids Love Tumble-Polished Stones!
If you visit a gift shop at a museum, cavern or science center you will likely see a cluster of excited children around a bin of tumble-polished rocks. They will be curiously prospecting through the stones, discovering, examining, comparing, ogling and selecting. Lots of geologists will tell you that their fascination with rocks was triggered by tumble-polished stones.
Kids Rock Tumbler Kits
A rock tumbler kit can be an educational gift and memorable experience for almost any child. Kids love the mystery of putting rough rocks into the tumbler and watching them convert into bright and shiny gems.
There are a few different rock tumbler models on the market designed especially for kids. These allow your child to experience the activity without making a large investment in equipment and supplies.
These tumblers are usually sold as part of a kit that contains everything needed to tumble one batch of rocks. The kit includes specially selected rocks, tumbling grit, rock polish and instructions. Some of these kits also include a few inexpensive jewelry mountings make gifts from the finished gems. Most of these kits are priced at about $50 or less.
All of the children's rock tumblers that we have seen are rotary tumblers which consist of a barrel to hold the rocks and a machine to turn it. Rocks, abrasive grit and water are added to the barrel and the barrel is placed upon the machine which turns it. The rocks are smoothed by abrasion as they tumble within the barrel. The tumbling action causes the rocks to rub against one another and with the grit, removing the sharp edges from the rocks and smoothing them. The rocks are tumbled for several days with coarse grit, then fine grit and then with at least one polishing compound. If you follow the instructions carefully and clean the rocks thoroughly between steps, the result will be a handful of nice, round, shiny rocks.
Rolling Stones & Smithsonian Tumblers
The kid's tumbler that we have seen most in museum shops and online is the "Rolling Stones" rock tumbler manufactured by Natural Science Industries, Ltd. The same company makes an almost identical product that is sold as the "Smithsonian" rock tumbler, the "SciEd" rock tumber and the "Edu Science" rock tumbler.
These small machines tumble about 1/2 pound of rock and are sold with enough rock, grit and polish to produce a single batch of rocks. The kit includes a few findings that can be used to make small jewelry items from the finished tumbled stones. The frame of the machine and the tumbling barrel are made of plastic (driven by a small electric motor) and are durable enough to complete the tumbling process several times.
If you use the tumbler that many times you will be ready to move up to a hobbyist's model.
Separate refill kits can be purchased for this tumbler. They include pre-measured quantities of rough rock, grit and polish - enough to run a single batch of rocks. The refill kits cost about $15. It might be a good idea to buy one at the same time that you buy the tumbler. We can tell you in advance that almost any child who sees the tumbling process all the way to the end and is rewarded with a fist full of bright, shiny stones will be ready to do it again right away.
Discovery Planet & Elenco Tumblers
The Discovery Planet rock tumblers are manufactured by Bowen Hill Ltd. They are sometimes referred to as "Elenco Electronics" rock tumblers (the name of their distributor).
They are sold as a kit that contains the machine, rough rock, tumbling supplies and some findings that can be used to make a few jewelry items with your finished gemstones. The kits are sold in stores and on the internet for under $50. They contain everything that you need to tumble one batch of rocks.
The Discovery Planet tumbler is a rotary tumbler designed to turn a small barrel filled with rock, water and abrasives to produce a small amount of polished gemstones. With it you can process about 1/2 pound of rocks (about a handful). It has two features not offered by the Rolling Stones tumbler described above. These are timer buttons used to set the number of days that you want the tumbler to run and a clear plastic dome that fits over the moving parts of the machine (not shown in the photo at right).
Refill kits can be purchased for the Discovery Planet tumbler. They sell for under $20 and contain enough rock, grit and polish to process a single 1/2-pound batch of rocks. Some findings and glue are included for making a few of your finished stones into colorful jewelry items. The refill kits can be purchased in stores, by mail and on the internet. If your child sees the tumbling process all the way to the end and is rewarded with a nice collection of polished stones he/she will be excited about the experience and ready to start another batch immediately!
Comments for Parents
We highly recommend rock tumbling as an educational activity for children. It introduces them to rocks and gives them experience with a manufacturing process. They will be proud of the gems that they produce and they might decide to give one or more of the jewelry items as a gift.
The most important lesson that the activity teaches might be patience - it will take a few weeks to complete the rock tumbling process. Short cuts do not pay because stopping the process early will result in a lower quality finish. It also teaches cleanliness. If even a few specks of grit are not washed from the stones and are included in the polishing process the finished rocks will be marked with scratches. This will be a very good lesson on the value of doing a thorough job.
Finally, think about where you might run the rock tumbler. They do make a bit of noise. Imagine the sound of small stones tumbling inside of a slowly turning plastic barrel. Most people who run tumblers locate them in their basement, garage, family room or in a closet with a door that can be closed. The noise is not deafening but you probably will not enjoy it hearing it in your bedroom at night or beside the television while you are trying to watch your favorite show.
Buy a Kids Tumbler or Hobbyist Tumbler?
Should you purchase a kids rock tumbler or one of the hobbyist tumblers described in our "Selecting a Rock Tumbler" article? The answer to that question should be based upon your budget and how much you think the tumbler will be used.
The kids rock tumbler kits described above are perfect if you want to give your child an opportunity to try the activity without spending a lot of money. You can get everything that you need by purchasing a kit for less than $50. But, keep in mind that they have a small capacity (about 1/2 pound of rock - an adult handful) and have a limited lifespan (a few batches of rocks).
If you think that your child will enjoy rock tumbling and you have the time to work with them regularly then one of the hobbyist tumblers might be a better purchase. A hobbyist tumbler kit with a single three-pound barrel, grit, polish and one load of rough rock will cost about $100 and last through many years of service.
Go back to the article Selecting a Rock Tumbler.
| Photograph of a "Rolling Stones" rock tumbler manufactured by Natural Science Industries, Ltd. This same model is also sold under the name "Smithsonian" rock tumbler, "SciEd" rock tumbler and the "Edu Science" rock tumbler. The tumbler runs on household electricity and is recommended for children who are ten years of age and up. The machine is about nine inches in length and the barrel is about three inches high and three inches in diameter. Refill kits are available and contain enough rocks, grit and polish for a single load plus some jewelry findings.
| Photograph of an open barrel and lid from the Rolling Stones rock tumbler. Note the ridges inside of the barrel to increase the tumbling action of the rocks and the rubber gasket in the lid to help prevent leaks. The barrel is about three inches deep and the opening is about three inches across.
| Photograph of a "Discovery Planet" rock tumbler manufactured by Bowen Hill Ltd. and sometimes referred to as an "Elenco" rock tumbler. The tumbler runs on household electricity and is recommended for children who are ten years of age and up. The base of the machine is about nine inches wide and eleven inches deep.
| Photograph of an open barrel and lid from the Discovery Planet rock tumbler. Note the ridges inside of the barrel to increase the tumbling action of the rocks.
| Photograph of the supplies provided with the Discovery Planet rock tumbler kit. Included are: jewelry findings, glue, rough rock, grit and polish packets.