“TUMBLE-POLISHING” STONES

by Ray Hill

I recall the joy of getting my first rock tumbler when I was 15 years old. It was a three-drum model and I could turn out a batch of beautifully polished stones every other week. I remember that my Step-Dad had built a tall display case, and in it I had display trays with many of my beautiful polished stones. I had the stones arranged by size and by stone type and where the stones were from. I also recall the pleasure I got when my mom would say to visitors to our house "Come look at what my son has made", and show off my treasures. That was a blessing.

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Collecting Chert at Gerard, Georgia Fossiliferous Chert

And, I recall that I had gotten a bunch of gold colored and silver colored bell caps from a mail-order place shown in one of my Step-Dad's rock catalogs. I would use a special adhesive and glue a bell-cap to the top of a beautiful polished stone then take the old-type black nylon fishing string and make a necklace with the tumbled stones. I sold literally hundreds of these fishing line and tumbled stone necklaces to my friends, neighbors, school kids and the like for a quarter a piece. (This was in 1959! Other than picking up aluminum cans and drink bottles on the roads in my neighborhood, I guess this was my first experience as an entrepreneur and sales person.)

I guess the one thing about tumbling stones that I truly got pleasure from was seeing the stones that I had personally found on a field trip turn into beautiful, shiny gemstones. And, this is the pleasure that each kid, young or not so young, gets from tumble polishing stones. It's that satisfaction of being able to say "I made that!"

Here are some very important things to keep in mind in doing rock tumbling:

1) Do not over load your tumbler. To work effectively, the material inside the tumbler has to have room to tumble and slide as the drum is rotating. Stay within the weight suggested by the machine’s manufacturer.

2) Be sure all stones you put in a load have the same hardness. You don't want to put calcite and agate in the tumbler together. Calcite has a hardness of 3 and agate is a variety of quartz with a hardness of 7. The soft stones will grind away to nothing before the harder stones are even ground smooth.

3) Always use a medium in with your grit and stones. This will help speed up the grinding/sanding/polishing process greatly. Plastic chips and beads are often used for this purpose.

4) Be sure to wash your stones and tumbler drum very thoroughly between each batch.. Leaving even a small amount of grit in your drum or on your stones between batches will contaminate that batch.

5) Don't try to "short-change" the process. Let the machine do the job it was designed to do. Go through the four stages of the tumbling process: Course grind. Fine grind or sanding. Pre-polish. Polish.

There are many fine articles on the Internet on the "how'-to's" of rock tumbling. Just go on-line to any of the search engines and type in "How to Tumble-Polish Rocks". You'll find lots of information there.

Happy Rockhounding.

Ray Hill
Great South Gems & Minerals, Inc.
www.greatsouth.net
888-933-GEMS

Note: Only rock clubs have permission to print this article but must give credit to the author, Ray Hill, and Great South Gems & Minerals, Inc. For everyone else, please email us for permission.

Great South Gems & Minerals, Inc. www.greatsouth.net 38 Bond Drive Ellenwood, Georgia 30294 USA 1-888-933-GEMS (4367) FAX 770-474-4507