Book Reviews

Rock & Gem Magazine Book Review. September, 2008—p. 30 (by William A. Kappele)

 Modern Rock Tumbling by Steve Hart

In nearly 14 years of writing the Shop Talk column, I have probably had more questions about rock tumbling than anything else. I jumped at the chance to review Modern Rock Tumbling by Steve Hart (Little Red Store, 2008), because I really am fascinated by tumbled stones, and the books that I have read on the subject didn’t really excite me.

Those of you who think tumbling is just tossing a handful of rough rocks, some grit, and some water into a drum and flipping the switch are in for a surprise.   Chapter One is a short history of tumbling and an overview of the development of abrasive technology. Chapter Two describes how to set up your tumbling area; discusses materials (abrasive media, storage containers, etc.) and proper storage techniques; and walks you through tumbling your first batch of rocks. You will even be shown how to make and use a “polishing stick”, which will help you determine whether your stone is ready for the polish stage or needs more time in the polish stage.

In Chapter Three, the author gets down to the basics of theory and practice in rock tumbling: sizing rocks, loading the barrel, grading, cleanup, and maybe most important, but often overlooked, recording all your steps, times, rock types, etc. so that when you tumble the same material in the future, you won’t have to run several batches to get things just right.

Hart then gives detailed explanations of what is going on in both the 4-stage and 5-stage (used for softer and more valuable stones) processes, Each step is carefully explained so that you will know how the stones interact with the various abrasives and polishes, and with each other.

Chapter 4 talks about the particle size of grits and polishes and how they are classified. You will also study rock hardness and toughness and the quantity of abrasives and polishes to use. The author explains how to use hardness picks to determine hardness to make sure that all of the stones in a batch are of the same hardness.

Chapter 5 is a discussion of the silicon carbide grits, the various polishing compounds, ceramic shaped media, plastic pellets, soap and burnishing powders. Characteristics of each are discussed as well as the types of rocks generally used with each.

Chapter 6 gives the process for working a wide variety of stones, including agate, jasper, obsidian (and Apache tears), jade and jadeite, wonderstone, abalone shell and colored glass.

Up to this point, the discussion has centered around the rotary tumbler. Chapters 7, 8 and 9 detail how to use the vibratory tumbler. Choosing a tumbler, grits and polish to use, getting the slurry right, and cycle times are all discussed in detail.

Steve Hart have given us an outstanding book that will be valuable for everyone from novice to master. It is well written, easy to understand, and well illustrated with nice color photos and charts where necessary. When I first took it out of the package, I thought the $24.95 price tag was a little high, but after I finished reading it, I realized that it is worth every penny.

--William A. Kappele

The Little Red Store, P.O. Box 5654, Oroville, CA 95966...


In the December, 2009 issue of "Rock & Gem:, Mr. Kappele writes further (in Field Notes):

 "There are lots of books on tumbling and lots of internet sites with instructions, etc.  I would recommend just one book: Modern Rock Tumbling, by Steve Hart (Little Red Store, 2008).  Although it is only 96 pages long, more information is packed into those pages than I have ever seen.  You can find it at ."