Dear Ethereal Llama,
First off, my name is not so neat or enticing to a greater universe!
My suggestion is to NOT set transparent stones in bezel with a back.
Unless the stone needs a backing to show color, etc, simply use an
open backed bezel. Gold will not present the problems of tarnish
apparent with silver alloys. If the gem does need backing, copy the
tricks of the Southwest USA "turquoise" jewelry trade. Most stones
are quite thin, backed with a layer of sawdust,etc. to build up the
height and make simple setting easy and quick but not a quality
workmanship, certainly. Yet, it does sell!
Try backing the stone itself, not the bezel. This might mean a
doublet type of work, sanding the back to flat(assuming cabochons)
and cementing with epoxy a suitable backing. It might mean coloring
an epoxy sugstsance with ceramit(etc) and letting it cure "on the
stone" before setting. Both will work.
I am sure others will have better suggestions than these, at least
this is start. I for one would go for the open back bezel and a
suitable stone in the first place. Otherwise, try liver of sulphur
if a dark back is desired in the full backed bezel or stuffing with
suitable material between the silver and the gem stone back. just
my simple thoughts. Thanks for getting to to think again tonight!
Thomas. a professional jeweler, worn out tendons.