Rock polishing:
turning stones into jewelry!
Tumbling rocks, stones to a high polish. For use
in jewelry, collecting, mosaics, crafts, and art
work.
Tumbled and polished rocks have been very
popular with hobbyists and collectors for generations! Tumbling
brings out details not apparent on a rough stone. Finished
stones can be collected and traded, or used for beautiful
jewelry, mosaics and crafts. You can find interesting samples
along stream beds or at the beach.
The process is quite simple. Place rough
mineral or rock in a cylindrical (barrel shaped) drum and add a
rough grit of silicon carbide. As the barrel rotates, its
contents collide, wearing down the stones (where they would
naturally erode in time).
A stone-tumbling machine can be found in most
hobby or lapidary supply shops. They range in price from about
$20.00 for a very inexpensive, child's model, to $700.00 for
serious, industrial uses.
A tumbler consists of an electric motor (in the
old days, it was done manually), a barrel, and a frame with
rollers. A pulley and a belt connect the rollers to the
motor.
To begin, fill a four pound or less barrel
almost three quarters full with stones of about ¼ inch to 1
inch in diameter. Add a rough grit of silicon carbide
(approximately ½ pound for every 2 ½ pound load, adding water
to cover. Every day (wait approximately 24 hours), stop the
machine, remove 10 stones and wash them under clean water. Then
allow them to dry and inspect them with a small magnifying
glass under bright light. If they are pitted or cracked, return
them to the tumbler and continue. When your samples do not
reveal these pits, cracks and hairlines, remove all the
stones.
Clean out the sludge in the
barrel. Wash the stones and the barrel well as the process will
be repeated a number of times. Sort for imperfect stones, and
place the good ones back in the barrel with other rough-ground
(or polished) stones until the barrel is almost three-quarters
full again. Add again the right amount of grit and water, and
repeat the process. Check it daily. Some stones may take up to
a week before they become perfectly smooth. Once done, ensure
the stones are well cleaned, and clean up your
barrel.
Now, for the final part. Return the stones you
have tumbled into the barrel for polishing! Add 1 tablespoon of
cerium oxide for every 2-3 pounds and just cover with water.
Tumble for up to one week until the luster of the rocks is
high.
Once highly polished, remove from the tumbler,
and clean the tumbler and stones as before. Return them to the
barrel for a final time with half a teaspoon of detergent
(laundry is fine), and water to cover. Tumble a final 6-8 hours
to remove the remaining film from the stones.
Rinse extremely well and dry and store in a
soft cloth or chamois.
Your rocks are ready for use in jewelry and
artwork! Use silver or gold wire to "cage" the stone and attach
to a chain or rope for a beautiful, one of a kind necklace and,
learn to identify and classify individual rocks.
This hobby is fun for all ages!
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