What to Use in Rock Tumblers

Rock tumblers can be used to create smooth glass, rocks and shiny gemstones. Rock tumblers come in a variety of sizes and styles, and samples of materials for a beginner to use are often supplied as well. Glass and small rocks approximately the size of a quarter are the materials most often used inside of the tumbling barrel.

Gathering Stones

Stones can be purchased specifically for use inside a rock tumbler, or can be gathered from outdoor hikes in the woods or on the beach. In addition to the hard tumbling materials, grit material and polishing powder must also be included during the tumbling process to smooth away rough edges and crevices. The rougher the rock or glass pieces are, the more grit and polish must be used. Rough materials increase the cost of rock-tumbling projects tremendously.

Large Rock

Rock tumbling artists and hobbyists often collect large rock from which they can create a specific color or style of project. The hardness of rock or glass used isn't a concern, only the size and jagged edges of the material to be tumbled are. To fit large rock or glass inside a home rock tumbler, crack it into smaller pieces with a ball-peen hammer. Safety glasses and work gloves should be used when cracking rock or glass. Rock or glass that is too thin, on the other hand, will more than likely break apart during the tumbling process. If the material to be tumbled can be cracked by stepping on it, then it is too thin to survive the rock tumbling process.

Rocks and Glass

Rocks and glass should not be tumbled together; the harder rock will crack the glass, grinding it into extremely tiny pieces. Rock purchased through a vendor will have weight and hardness of the rock noted on the packaging. It is equally important not to tumble rock of different hardness levels together inside the tumbler. Hard or large rock will grind the smaller or thinner rock into small pieces. Hard rock and glass make a similar combination, resulting in sharp pieces and an unsuccessful project.

Rock Types

The types of rock most commonly used inside a tumbler include lapis, feldspar, jasper, chalcedony, kyanite, labradorite, helitrope, agate, aventurine, amazonite, coral-agate, chrysocolla, calcite, carnedian and chrysoprase.

Ocean Glass

Nearly any type of glass can be used inside a tumbler, providing it isn't too thin to tumble. Ocean or sea glass is created after glass that finds its way into the ocean is tossed around in sand and salt water, creating a smooth-sided frosty piece of material. It is found naturally along the beach, but can also be synthetically created, as a tumbler can simulate that very process. Stained glass scraps, old coffee cups, dinnerware or various glass fixtures or decorations picked up at a flea market will suffice. Do not mix heavy glass with lighter-weight glass, or the latter will be ground into fragments. Natural shark or alligator teeth can also be tumbled to remove rough edges.

References

• A rock tumbling website