No, it's safe for stones. Works best with "washing soda", rather than baking
soda (sodium carbonate instead of sodium bicarbonate). No salt needed. Make a
warm solution of either chemical in water, place the aluminum foil (or use a
plain unanodized aluminum pan instead) in the bottom of the glass or plastic
container, and put the silver on top, in the solution and in contact with the
aluminum. It sets up an electrolytic reaction that reduces the silver sulphides
(tarnish) back to silver. If the tarnish is more than slight, though, the
result won't be bright metallic, only white in color again. (Tarnex has this
same limitation) So more severely tarnished pieces may still need some buffing
to restore the finish, and doing that also helps retard future tarnishing again.
Depending on the degree of tarnish, this can be a somewhat slow process, so be
patient. It's not instant the way Tarnex is. Sometimes takes up to a couple
hours, and sometimes you may need to reheat the solution during the process.



Thanks Peter, for the info. I've googled this cleaning process for silver and
have read where some
believe it wont harm the softer stones, and others believe it does so I came
here for the definitive
answer. I just wanted to be able to offer my customers a way to clean the
silver in their jewelry
without harming the other components or stones.