How to Tumble Garnet

Gently wash your garnets in warm water and add about 4 tbsp. of the stones to a 3-pound tumbler drum. Any more than this and the tumbler will go off balance because garnets are so dense. Add about a cup of water and 2 tbsp. of 90-grit granules. Allow the stones to tumble for about a week.

Place screen fabric in the bottom of a plastic tub and fill it about halfway with warm water. Remove the stones from the tumbler and rinse them carefully in the tub. Lift the screen fabric out of the water with the stones on top. Set the fabric aside and examine the stones. Set aside any broken garnets and put them through the first step again. Dispose of any stones under about ¼-inch; they are too small to be tumbled.

Put all of your rounded, unbroken garnets back in the tumbler with about 4 tbsp. of 220 grit and a cup of water. Let the stones tumble for about another week, and repeat Step 2.

Repeat Step 3 with 3 tbsp. of 400 grit to give the stones a fine, matte polish. Repeat Step 3 again, using pre-polish for 10 days, and then using polish for two weeks. This should give your garnets a high sheen. Pre-polish and polish are different grades of ammonium oxide that will smooth the surface of the stones.

Break up one bar of unscented white soap into chunks about the size of a dime. Add half of them to the tumbler with your stones and a cup of water. Let the tumbler run for about four hours. This neutralizes the polish and helps clean the stones. Rinse your stones with water thoroughly.