What is tarnish in sterling silver?
Over a period of time silver jewelry starts to show changes in color and turns from a yellowish tint to deep yellow and even black. This is called the tarnishing of silver and is a natural process. The notion that silver tarnish only occurs with silver jewelry made from low purity silver is not correct.
What causes silver to tarnish?
Sulfur containing materials generally cause silver to tarnish and Hydrogen Sulfide is just one of these. Materials like wool, rubber bands, fuels derived from fossils, a few types of paints and rubber (latex) gloves are some of the common materials that cause tarnishing of silver. Certain foods like eggs and onions also hasten the silver tarnish process. You can therefore realize that, touching silver jewelry with oily hands or after a meal could also stain your silver jewelry with tarnish. The extent and speed with which your silver jewelry tarnishes is also related to the climate and in general, high humidity would result in silver tarnishing much faster. Never wear your jewelry while swimming. Chlorine is a major cause of tarnish.
What causes “green finger”?
Silver will sometimes cause skin staining, usually black or green. In most cases this causes no physical harm and is an aesthetic rather than a health problem. Silver will naturally turn black when it oxidizes. The amino acids in your skin can accelerate this. When it is hot, two factors occur. The metal is more reactive to oxidation when it is warmer and perspiration can cause a chemically reactive climate. If the jewelry turns color you can polish it, if the skin turns color you have to decide how much this bothers you. In cooler weather the problem might go away but it could be that your chemistry is not compatible with the material. When silver or the skin it contacts turns green it is a reaction with the copper in the alloy. Some customers have had good luck polishing the inside of their rings daily for the first week or so. Sterling silver is 92.5 % pure silver. The other 7.5% is other alloys, usually copper. As the copper reacts and is polished away there is a gradual depletion of the copper near the surface available to react with the chemistry of the skin. As that copper is depleted the problem lessens. If you have an actual rash, blistering, irritation or infection by all means take the jewelry off until it clears up. Other factors besides the metal may be causing the problem. Most frequently soap trapped behind the ring irritates the skin or persistent dampness behind the ring causes a rash. Be sure to rinse well and dry under the ring, especially if the ring is a wide one. There are ways to eliminate staining. One is to choose stainless steel jewelry when possible. Another is to coat the jewelry with clear nail polish where it touches your skin.
What is antiquing
Antiquing is the process of darkening the recessed areas of gold or silver jewelry to enhance the visibility of engraving. Antiquing is a chemical process used to create an oxidized look.