I have had to replace bezel set stones in onyx quite a few times, and
even drill stones and set tube settings into other larger stone a few
other times. It is a pretty straight forward process. First of course
you need to drill the larger stone, and diamond bits are the way to
go. After you have your center hole it makes for a cleaner job to
slightly countersink the top of this hole the same diameter as the
bezel setting, so the bezel sits down into the material nicely, even
down till the bezel is flush with the larger stone is possible. The
reverse of the stone also should be countersunk slightly, or a cross
groove cut to help secure the tube.
I solder the bezel onto a piece of tube (traditionallysterling silver
as it’s soft and easy to flair/tighten, but that is your choice).
This tubing should be a snug fit through the center hole, and longer
than the thickness of the larger stone. I then set the diamond, and
do all my finnishing of the bezel while I can still hold it in my pin
vise. An old watchmaker’s lathe is wonderful for this type of setting
and finnishing of tubes and bezels, if you have access to one!
After the bezel is completed I trim the excess tubing till it just
protrudes a couple mm’s beyond the reverse of the stone. I push the
bezel into place and turn the peice upside down onto my benchpin so
that only the bezel is touching the surface of the pin. I then
gently rock a taperred punch into the end of the tube to flair if,
and then very gently push and then burnish the tube end down onto and
into the countersunk recess to tighten the bezel. I then trim away
any excess tubing metal and pollish. I once had a loose opal to set
that had had a bezel set diamond countersunk into it in this same
way, and although I do not think that I want to be the one setting
tubes into opals it was an awfully nice look!