Directions for Tumbling & Polishing Agates

Coarse grind

• 1

  Add the rough tumbling rocks to the barrel with the recommended amount of coarse grit as per manufacturer's instructions. For example, for a 3-lb. tumbler, about 4 tbsp. of coarse grit are recommended. The rocks fill the barrel up to at least half full. If you do not have enough rough rocks, you can add plastic pellets to fill it up to half.

• 2

  Add water until it reaches the bottom of the top layer of rocks.

• 3

  Clean and dry the rim of the barrel and the lid to make sure they seal well when put together.

• 4

  Seal the lid on the barrel, place it on the tumbler and start the motor.

• 5

  Check the tumbler to make sure it is running and the barrel is not leaking.

• 6

  Run the tumbler for a week, checking it occasionally to make sure it is running well and has no leaks. You can open the barrel if you want to check the process, but make sure to clean and reseal it well.

• 7

  Place the strainer over a bucket and empty the barrel into the strainer after about seven days.

• 8

  Rinse the stones well to remove all the grit.

• 9

  Check the shape of the agates to be sure they are how you want them; if not, you can repeat steps 1 through 8 to round them further using fresh coarse grit. You can pick out the rocks that are acceptable and put them aside for the next step.

Fine grind

• 10

  Clean the barrel, lid and rocks of any coarse grit. It is important that no coarse grit be present during the fine grind or it will scratch the rocks. Use a toothbrush to scrub the inside of the barrel; use a separate toothbrush for each level of grit. Mark the toothbrush with the appropriate type of grit, such as "Coarse."

• 11

  Repeat steps one through eight from the coarse grind section, using fine grit. Use 4 tbsp. of fine grit for a 3-lb. pound barrel.

• 12

  Clean everything well to make sure there is no fine grit on anything.

Pre-polish, polish and burnish

• 13

  Repeat steps one through eight from the coarse grind section, using the pre-polish grit. You can use some plastic tumbling pellets to help cushion the rocks. The rocks, pellets, grit and water should not fill the barrel more than three-quarters full. Use 5 tbsp. of pre-polish grit with a 3-lb. barrel.

• 14

  Clean the pre-polish grit from all the rocks and equipment.

• 15

  Repeat steps one through eight with the polishing compound, using plastic pellets again to cushion the rocks. Use 5 tbsp. of polishing compound with a 3-lb. barrel. Do not re-use pellets that you used with a different level of grit. The agates should appear shiny when dry after this step. If not, you can try burnishing them.

• 16

  Burnish the rocks by adding them to the tumbler with fresh plastic pellets, water and shavings from a bar of soap. The soap should have no grit, and you should not use liquid soap. For a 3-lb. barrel, use 1 tbsp.of soap.