Like gold, silver in its pure form is too soft to use in jewelry so other metals are added to it to create sterling silver, which is at least 92.5% silver. Those other metals, primarily copper, are the reason sterling silver tarnishes. The copper reacts to the moisture and sulphur in the air — first the sterling silver gets a golden cast and then it turns dark. Acidic foods such as onions can also cause sterling silver to tarnish.
The tarnishing process is much quicker in an area with pollution in the air and water nearby causing a humid atmosphere. Keeping sterling silver in a dry airless environment, such as an airtight plastic bag, will help slow down the chemical process that results in tarnish.
“Fine silver” is 99.9% silver. Since there is very little copper in the alloy, fine silver tarnishes much more slowly than sterling silver. It's also very soft so it's used mostly for chains and bezels to hold stones in place. In general, the higher the silver content, the slower the tarnishing. Even fine silver, though, will eventually tarnish. Again, proper storage will help slow down the tarnishing process.
A new highly tarnish-resistant silver alloy is now available: Argentium™ Sterling Silver. It's sterling silver because there is at least 92.5% pure silver in the mix, but some of the copper is replaced by another metal called germanium. Germanium bonds easily with oxygen and forms an invisible protective barrier that greatly slows down the tarnishing process. If jewelry made from Argentium sterling silver is stored properly, it may never need cleaning. There's more information about this exciting new tarnish-resistant silver at Argentium Sterling Silver.
As every silver lover knows, jewelry made from traditional sterling silver needs plenty of care. Most of our advice about how to clean silver jewelry is similar to the advice given about how to clean gold jewelry. Tarnish looks a little different on gold, a little redder, but copper and the chemical process are similar in both gold and silver.
The first step in cleaning silver is to be gentle. Silver can be easily scratched.
Do not use toothpaste to clean silver jewelry. Toothpaste is meant for tooth enamel, the hardest substance in a person's body. Toothpaste and scrubbing with a toothbrush are much too abrasive for silver.
Do not use baking soda to clean silver jewelry either. There is a silver cleaning “trick” on the internet about lining a pan with tin foil, adding hot water and baking soda, and letting your silver jewelry sit in it. Don't do it! It will cause tiny pits to form in which chemicals and moisture can be trapped and eventually cause damage.
There are many silver cleaning products available, but tarnish on silver jewelry can be removed simply by washing your silver jewelry with warm water containing a few drops of mild dishwashing liquid such as Dawn, Ivory or Simple Green. Do this often and your silver jewelry will never develop the dark tarnish that is hard to remove.
If your silver jewelry does not include pearls or soft gemstones, immerse the jewelry in the sudsy water, and rub gently with your fingers or a cotton swab. For more abrasive cleaning (only when needed), brush lightly with a soft baby toothbrush. Rinse the piece thoroughly with warm water and dry with a cotton cloth to avoid water spots.
If your silver jewelry does include pearls or soft gemstones such as turquoise, do not put the jewelry into water. That can damage the polished surface of the stones. Instead, moisten a cotton swab with diluted dishwashing liquid and with that carefully wipe the silver surfaces that need cleaning. It's especially important to store such silver jewelry carefully to avoid having to do such painstaking cleaning. Wipe the silver with a damp cloth or cotton swab to remove the soap.
Before storing, let your clean silver jewelry lie flat and air dry completely, overnight if possible. Moisture speeds up the tarnishing process so it's important to make sure your silver jewelry is thoroughly dry before storing it.
Once your silver jewelry is dry, if it looks dull, polish it with a non-abrasive jewelry polishing cloth. Use a clean cloth, or a clean section of a previously used cloth, so that the silver is not scratched. It's a good idea to use separate cloths for silver and gold. To avoid forming a pattern, rub the polishing cloth in straight lines, not in a circular motion. Occasionally, change the direction of the straight lines.
Machine cleaning: If the above methods are not removing old dark tarnish from your silver jewelry, it's best to take your silver jewelry to a professional jeweler for more aggressive machine cleaning. Most jewelers have some type of automatic cleaning equipment, such as an ultrasonic cleaner, and experience using it so they can thoroughly clean your silver jewelry if it's safe for your specific piece of silver jewelry. The ultrasonic machines used in jewelry stores heat the cleaning solution and are more effective than the small ultrasonics sold for home use.
Professional polishing: Clean silver jewelry that still isn't looking like new may be scratched and in need of extensive polishing to be shiny again. This buffing process is done in stages with abrasive papers, not with a polishing cloth, and is a job for your local jeweler. Such polishing will remove some silver so storing your jewelry carefully will save your silver, and save you some time and money, too.
When storing, wrap your clean silver jewelry in anti-tarnish tissue and then put it into a plastic bag. Squeeze as much air out of the bag as you can before closing it. Wrap each piece of clean silver jewelry separately so the pieces don't get scratched by rubbing against each other.
If the jewelry is a delicate chain, stretch the chain out onto anti-tarnish tissue, roll up the tissue as you'd roll up a carpet, lay the roll flat inside a big plastic bag and seal the bag tightly. To fit the wrapped chain into a smaller bag, curl the “carpet-roll” into a loose coil and put that inside a plastic bag. Rolling up your silver chain in anti-tarnish tissue will keep the chain from getting knotted and also slow down the tarnishing process.
As with all jewelry, do not wear silver jewelry in a swimming pool or hot tub or when using ammonia or cleaning bleach at home. Bleach, including chlorine, will attack and dissolve the metal so that the more delicate parts will come undone. Don't wear silver jewelry in the shower either. Soap residue builds up causing a dull finish on the silver that's difficult to remove. Also, don't use rubber bands to wrap your jewelry bags together. As rubber bands age they release sulphur so don't keep any rubber bands near your jewelry or in your jewelry box. Other sulphur producers that you should not use for storing your jewelry are newspapers, clingy plastic wraps, non-archival cardboard boxes, leather, and silk.