Can I use walnut shell with stone-set jewelry? Including turqoise
NO Any abrasive action will attack the softest part of the stone and
leave it undercut. Tumbling turquoise by its self is a task not
easily mastered and requires much experimentation to get a mediocre
finish. Also, what works on stone from one batch might not on the
next batch due to the differences in the stones. NEVER attempt to
tumble amber. To attempt to polish out a piece of jewelry with the
stone set is asking for trouble. To attempt to polish out more than
one at a time is asking for a disaster.
The use of walnut shell is best confined to large smooth pieces with
no inside corners or pattern. The walnut shell is crushed to about
1/5 to 2mm in size and will not get into corners or cracks well. To
do this, you need an assortment of polishing shot, pins, triangles,
flying saucers, ball, etc. along with a good polish media like a
burnishing soap. Using this combination on jewelry with the stone
set, especially on turquoise and amber, is sure to trash the stone.
Lastly, fire scale is best resolved in methods other than tumbling.
You can't control where a tumbler is going to "polish" or grind off
metal so if you were successful in removing the fire scale, you
would also grind off a similar amount of metal from the rest of the
piece, and most of that would come off high parts of the piece,
destroying any pattern.