Often the most difficult part of protecting gemstone jewelry is the metal setting. Everyday substances like hairspray, lotions, perfumes, or other cosmetics may corrode the alloys used in a setting or in metal jewelry. Exposure to chemicals can discolor gold, silver and platinum as well as other metals. Ammonia, one of the chemicals most commonly used in household cleaners is particularly harmful. Chlorine bleach, another common household solvent, can cause pitting in gold alloys. Metal jewelry may be cleaned with commercial cleaning solvent or with mild detergents such as dish washing liquid. You should consider the softness and age of the metal before selecting a cleaning brush. Toothbrushes are fine for harder, newer metals while soft make up brushes are a good option for older and softer metals. Dry thoroughly with a soft, lint-free cloth.
Water, oils, and even air can cause metals to tarnish. When not using jewelry, especially sterling silver, its a good idea to store it an an anti-tarnish bag or cloth.