I do not recommend the following method of removing tarnish if the jewelry contains dyed, delicate or
easily damaged stones such as Malachite, Opal, Turquoise, Lapis Lazuli, Coral, Amber, Pearls, etc.
Tarnish may be removed from sterling silver jewelry by soaking it for a few minutes in a small aluminum pot, or a small pot lined with aluminum foil, and a mixture of 1 teaspoon baking soda, 1 teaspoon salt, and 1 teaspoon liquid soap dissolved in hot water. The metal of the jewelry must be touching the aluminum pot, or the foil. If the tarnish is stubborn, bring the mixture to a slow simmer for a couple of minutes.
People will argue that it needs to be washing sode instead of baking soda, but they all work