Years ago (probably 30) I bought a small jar of fire opals covered in water from a rock shop. They're rough pieces between 1/2 and 1 inch. The shop was going out of business and I think I paid $1 for the bunch. Anyway, it's been sitting in my kitchen window ever since, picking up the light that comes in and giving little flashes of fire.

I have a Lortone tumbler for my polymer clay beads and the only polishing medium I've used thus far is sandpaper chips.

I'm wondering if I can polish these opals in my tumbler without wrecking them. From what I've read, opals might not be good candidates for rotary tumbling. I have some steel shot.

Any advice? They can always just continue to sit in their jar of water in my kitchen window.
 

Hi Linelle,

Lucky you, what a steal for a mere dollar!

You should be able to tumble those opals in your rotary tumbler without any problems. But keep in mind that tumbling takes time. And lots of it. Your tumbler won't be avaliable for any of your polymer clay beads for a number of weeks. Even though opals are soft, they'll still need to tumble day-and-night for quite a while to polish up nicely.

Linelle:

I have some steel shot.

Please please please don't load any steel shot into that tumbler with your pretty opals. Steel works well for polishing up metal, but for stones you need tumbling grit. It's sort of like powdered sandpaper. You tumble the rocks in each grit before moving down to the next-finer grit, and then your eventually tumble with polish.

If you don't have a local rock shop, just search for "rock tumbling grit kit" on any search engine. You should find plenty of retailers that offer introductory kits with the necessary grits and polish for around $7-20. It may help to pick up an inexpensive book on tumbling while you're at it.

I'd love to see a before and after pic in the gallery once you're done.
Good luck!
~Addie~ 

 Hi Addie, thanks for the great info and advice. I really appreciate it. I'll look for some tumbling grit. I wouldn't want anything bad to befall these opals, since I've had them for such a long time and they give off such lovely glints of fire. When I finally do tumble them, I may just do half to see what happens.

Thanks again!
 

Use a trim saw with a thin blade to cut out the opal area desired on large pieces if:

1. It cannot be used as one whole piece, or
2. To obtain a certain size.

Use the trim saw also to trim off large areas of waste or excess material. Some of the cutoff remnant pieces can also be shaped and finished. Always apply water to cool down the stone and blade and to wash away the debris.