Tumbling media has three functions: 1) it delivers grit to hard-to-reach rock surfaces; 2) it is used as a filler when tumbling a partial load; 3) it is used to cushion fragile rock materials during the tumbling process. Plastic pellets are to be used in rotary tumblers (they produce too much "bounce" in a vibratory). Ceramic pellets are used in vibratory tumbling but many people also use them in rotary tumblers. If you are tumbling a load of large rocks they will have very few points of contact. However, if you add ceramic cylinders to fill the voids between the rocks there will be a lot more points of contact where grinding action can occur. The result will be faster grinding and smoothing done on surfaces where rock-to-rock contacts would not occur.
Large ceramic pellets work great as a filler and for delivering grit or polish to difficult-to-reach surfaces. These angle-cut cylinders are approximately 3/8" (9mm) diameter x 5/8" (16mm) long. They can be washed and reused along with your rock. When used in the fine grit and polish stages they will last through many tumbling cycles.
Small Ceramic Tumbling Media
We Use These for Cushioning
Ceramic pellets work great as a filler and for delivering grit or polish to difficult-to-reach surfaces. These angle-cut cylinders are approximately 3/16" (5mm) diameter x 3/8" (10mm) long. They can be washed and reused along with your rock. When used in the fine grit and polish stages they will last through many tumbling cycles.
Plastic Pellet Tumbling Media
Use these plastic pellets to cushion fragile stones when tumbling in a rotary tumbler or as a filler. The pellets are about 3/16" (4mm) in diameter and float for easy separation from rock. They can be reused multiple times in the same size grit. (Not for use in vibratory tumblers.)
A video showing use of the different tumbling medias above
We highly recommend:
Modern Rock Tumbling by Steve Hart.
Learning is the fastest way to improve the quality of
rocks that you tumble. In this book you will learn from an expert with extensive
experience. You will increase your abilities, learn to save time, money and have a great reference book
that you will use again and again.
Gemstones of the World
We highly recommend:
Gemstones of the World (fifth edition) by Walter Schumann.
One of the most popular gemstone books ever written, with over one million copies sold. It has about 100 pages of basic gemstone information and about 200 pages dedicated to photos and descriptions of over 100 gems and gem materials.