100% solid silver won’t tarnish but it is too soft to use for making jewelry – it could easily be scratched, dented and bent.
Sterling silver has a small amount of one or more other metals usually copper, added to the silver. To be called sterling silver, the alloy must contain at least 92.5% pure silver. Sterling silver alloy is harder than pure silver but the added metals also can cause discoloration or tarnish.
Tarnish or Rust?
Both tarnish and rust are due to exposure to air. Rust occurs when items such as those containing iron, combine with oxygen to form iron oxide. Rust eats into and deforms the iron, degrading its strength.
Tarnish, on the other hand, is a layer that forms on the surface of a silver alloy, for example, when the item is exposed to sulfur or hydrogen sulfide in the air. The chemical reaction that takes place produces silver sulfate, the smoky, gray or black residue that some people dislike. Others love it – it is called patina. Interestingly, a layer of tarnish actually protects an item from further tarnishing.
|PatinaPatina is the film on the surface of an item produced by chemical changes over a long period of time. The green patina on the Statue of Liberty is verdigris, a normal darkening of copper when it is exposed to the atmosphere.
Patina is what gives older silver pawn jewelry its character. That’s why in our pawnshop, we never remove patina – we let the new owner decide if they want the item to show its age or to be shiny. Authentic patina increases the value of old Native American pieces.
Sulfur content in the air varies depending on location. Air near volcanic activity, some industries and heavy traffic can be high in sulfur. Homes built within the last 10 years or so that used drywall from China have been found to have very high concentrations of sulfur.
If you want to keep your sterling silver jewelry bright and shiny, here are some tips.
When you remove your jewelry, look for a build up on the inside of a bracelet or the back of a pendant, this is usually caused by sweat, make up, sloughed skin cells and the like. Carefully wipe the jewelry with a damp cloth or sponge to remove the buildup. Although silver doesn’t rust like iron, the salt in sweat can be corrosive to silver-copper alloys such as sterling silver so you want to remove any caked-on sweat or residue before storage. If your jewelry piece has stones, take care not to get the stones wet as it could loosen their settings.
- Minimize contact of your jewelry with moisturizers, perfume, and makeup.
- Remove your silver jewelry before you go swimming or if you can’t part with it, rinse it off promptly after swimming.
- Store your silver jewelry in a dark, low humidity area. Sunshine, high humidity, body sweat and oils all hasten tarnishing. (see complete list below)
- Wrap large valuable pieces in anti-tarnish cloth (ATC), store in ATC pouches or line your jewelry boxes or a jewelry drawer with ATC. You can purchase the cloth by the yard – it is the same type that lines your silverware box. (Watch for a future edition of PP for photos of jewelry storage drawer ideas. Go here to see anti-tarnish pouches.
- Buff jewelry pieces with special silver polishing clothsto remove fingerprints and tarnish before wearing.
- Do not use polishing cloths on the stone portion of your jewelry.
For more serious cases of silver tarnish, there are many products and methods you can try but I am reluctant to recommend any until I have time to test the methods myself.
Things that cause tarnish on your sterling silver jewelry:
- Skin Oil
- Hair products
- Anything with sulfur in it
- Chemicals in clothing and detergents
- Air pollution
- Some types of plastic bags