Working with simulated opal inlay

I rather rashly agreed to make my sister a cast gold ring inlaid with
Rio’s simulated opal block, and having tried cutting the simulated
opal have realized that this might not be the best project to use to
learn inlay! Does anyone out there have any words of wisdom on
working with this material? I have access to a diamond saw, but the
inlay needs to be curved in two planes (around the ring and up and
down on the ring) so I am not sure that helps. I can cut it very,
very slowly with a standard jewelers saw blade, and have also
purchased a diamond blade for the same saw, but find that it makes a
very wide cut. I would also appreciate any general advice on inlay,
having only done it with polymer clay in the past, which is of
course very forgiving!

I would also appreciate any general advice on inlay, 

I do a lot of inlay with turquoise and lapis and other stones. I
haven’t worked with simulated opal. I sometimes use a 1" diamond
cutting wheel on my flex shaft to cut small pieces. Separating disks
would probably work on the simulated opal. Cut slowly to avoid
heating the simulated opal or cut it in a small dish of water. For
shaping I use an 8" flat lap and a diamond coated drum sander about
3/4 of an inch in diameter on my flexshaft. You could probably get
away with a cheap set of diamond files.

If you could get someone with a lapidary diamond saw to cut the opal
in 1/8 to 3/16 inch slabs would be a good start.

First start by cutting the opal in the approximate size and shape.
Then shaping the opal to fit the inlay channel. Your diamond files
would be best for this. Once you are satisfied with the fit in the
channel shape the inside of the piece with diamond drum sander on
your flex shaft or a round diamond file. You can lay the opal
alongside of the channel to check how it will fit the curvature.
Don’t worry about shaping the stone on the surface. That will be done
in the final steps.

Once you have the stone fitting properly it’s time to glue it. I us
CA Special T (look for the green label0 cryogenic adheasive (super
glue). It has a thicker consistency than most of the cryogenic glues.
You can buy it at Woodcrafters woodworking store. I glue one piece at
a time and use the setting spray. Before the glue sets up completely
clean up the excess glue in the channel with a sharp xacto blade.

Once you have all the stones glued in it’s time to grind or file the
stone even with the channel. Then smooth it with progressively finer
sand paper. I use diamond coated laps for this but wet/dry sandpaper
should work. Then polish the piece with Zam.


Rick Copeland
Silversmith and Lapidary Artisan
Colorado Springs, Colorado