Karen, This is not too difficult to accomplish.
The pieces were done in 18kt yellow gold, and involved
large-diameter (1/4" up to 3/4"), thin gauge jump rings
The key here is that the rings are thin, large, and 18k gold. Since
the gold doesn’t conduct heat as efficiently as silver, it would be
a simple matter of applying a heat sink (locking tweezers will work)
on either side of the joint. You could use Cool Jool, or even water
on a wet piece of paper towel, to protect the stones, if you wish.
I'm using a Smith Silversmith torch (acet/air) do I stand a
chance of accomplishing it, or would it be only possible with a
Possible, but more difficult than using a torch with a tiny flame. A
"Hoke" torch would be an improvement, and it is much easier to work
in gold if you can control both the gas and oxygen separately.
Briolettes have become popular again, and shouldn’t be too difficult
to find, especially if you’re in NYC. Of course, diamonds,
sapphires, and rubies would be easier to solder, since they can take
more heat than andalucites.
With skill and practice, and perseverance, you can accomplish almost
anything. I know that I could solder silver jump rings like these
with a Presto-lite torch (or even a blow pipe) if I had to. I’ve
been doing this for a long time. I learned by trying, sometimes
failing, and trying again and again until I got it down.
Go for it!