Dear Barb, In response to your quote below, I would like to share a
turquise doesnt tumble well, though you can buff the stones after
being tumbled and it brings up the surface again. i have tumbled
amber before and pearls, and they are both ok but only for short
times, more to reshine a dull surface rather than polishing.
Tumble polishing with a dry media (corn-cob, walnut shell or wood
products) treated with one of various compounds, (chrome oxide, iron
oxide, meta-gloss, diamond powders, etc. depending on what you are
polishing) can actually do a fantastic job on turquoise and many other
stones. There are many, MANY different stages and applications for
the various materials you can tumble finish and each one can save a
tremendous amount of time in the “final hand polishing” stage. We
have done sample mass finishing runs on materials from metal, plastic,
stone, egg-shell, wood, and various other things items that might even
be somewhat unexplained. The Rio Grande Product Lab does this service
at no charge and sends back a full report on the machinery, media,
compounds and time cycles along with recommendations of ways to make
your life easier. You might want to look into this by contacting Rio
Grande at www.riogrande.com.
Hope this helps with you finishing.