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How to Polish Olivine in a Rock Tumbler

Rock tumbling is an easy-to-learn hobby that anyone can enjoy. Kids learn about geology in a hands-on way, and adults find that the polished semiprecious stones make decorative ornaments, gifts and jewelry. Many kinds of stones in many different colors can be polished in a rock tumbler. Olivine is a popular tumbling rock because it has an attractive color ranging from olive to yellowish green. It's not a hard mineral, so it's easy to tumble and polish.

Things You'll Need

Rock tumbler with grit media, polish and plastic pellets
Unpolished olivine
Water
Paper towels

Instructions

- 1
  Fill the tumbler barrel 2/3 to 3/4 full with your olivine samples. Add the amount of coarse grit that your tumbler specifies. Fill the barrel with enough water to almost cover the rocks. Clean and dry the barrel rims and lid edges, and secure the lid to the barrel. Place the barrel on the tumbler and run the tumbler constantly for seven days. Rinse the mud off the rocks and clean them well. Thoroughly clean the barrel and lid.
- 2
  Repeat Step 1, substituting fine grit for the coarse. If the barrel is less than half full, add plastic pellets to achieve the desired volume.
- 3
  Repeat Step 2, substituting extra-fine grit (or pre-polish) for the fine. Add plastic pellets to cushion the stones.
- 4
  Repeat Step 3, substituting rock polish for the extra-fine grit. Run for 10 days rather than the previous seven.

Rocks & Minerals