I recently attended a Jewelry Trade
show featuring some incredible hand set
jewelry using mosaic opals set in Sterling Silver.
The Jeweler showed us a trick I wish I would have known before.
Just by rubbing the baking powder on the sterling silver the tarnish was removed with no harm to the precious opal gems.
This will work for turquoise, coral and many other gemstones.
Remember Baking Powder not Baking Soda.