Care of Your Bullion Products - Why do silver and gold products tarnish?
Tarnishing occurs when natural gases in the earth’s atmosphere (hydrogen sulphide) react with the surface of your silver. The problem can be more pronounced in areas of heavy automobile traffic and places of high humidity. Eggs, onions and other foods high in sulfur can also cause silver to tarnish.
Gold by nature shouldn’t tarnish. It is usually the added metals in the coin or bullion that degrades with time (this happens to .9999 grades as well). But not to worry, those little red spots or tones you see are extremely common, a true investor knows that it does not affect the value at all.