I use Tarn-X all the time to clean my base metal jewelry (if I
haven’t oxidized/patinated it). A quick dip (1-2 seconds) and a fast
rinse & dry does the trick. When followed by a few quick rubs with
the silver polishing cloth, the brilliance is back! Tarn-X contained
acidified thiourea (whatever that is), and sometimes it smells like
rotten eggs, but I can put up with that, compared to the time and
mess of using something like Brasso.
I put the Tarn-X into one of those dipper bottles, and you can use
the same small batch over and over again. No need to throw it out
use, although you may want to make up different dipper bottles for
dipping different metals. For slightly larger items, handy dipper
containers are those Tupperware pickle holders, which show up at a
lot of garage sales.
The Tarn-X bottle says not to dip (among other things) "pearls and
stones." Things like agate do not seem to be bothered at all by
Tarn-X. I have a large lapis cab, in a brass setting, which I have
dipped (occasionally and rapidly) for years, and it doesn’t seem to
damaged the stone. It may look a little dull, but oiling it (with,
e.g., hand lotion) brings back the sheen to the lapis, which never
high sheen in the first place.
I can’t make any guarantees, but these are just my experiences.
Judy Bjorkman Lenandjudy@acmgfcu.net