Why Sterling Silver Tarnishes and How to Stop It

Jewelry Metals

Why Sterling Silver Tarnishes and How to Stop It

The short answer to the question of "does sterling silver tarnish?" is yes, sterling silver does tarnish. All metals tarnish, but it's particularly unwanted on sterling silver due to the fact it obscures the gleam of the metal. Tarnish turns a piece of sterling silver different colors at first, then eventually turns it black if it's not polished regularly or kept in a sealed container.

Exposing sterling silver to air and other chemicals begins a process known as oxidation. Some metals rust while others pick up a patina. In the case of sterling silver, the coating that forms is known as tarnish. It's unsightly and obscures the color of the metal along with detracting from its looks. 

Fortunately, tarnish isn't permanent, and you can easily remove it with some household chemicals, a cloth, and a little elbow grease. It doesn't take much to restore a piece of silver back to its original condition. Once you've finished cleaning your silver, you can protect it against further tarnishing through proper storage techniques and save yourself the time and effort of cleaning your piece the next time you want to wear or use it.  h 

Why Sterling Silver Tarnishes

Sterling silver tarnishes due to the fact it's been alloyed with copper to make it more durable. Pure silver, or silver that's .999% pure, doesn't tarnish because it's not alloyed with any other metal. However, pure silver is fragile in nature. Adding a 7.5% of copper or other metals to pure silver results in the creation of sterling silver, a more durable metal that's perfect for making into jewelry and decorative items. 

The addition of a second metal, usually copper, to pure silver makes it tarnish when exposed to the elements and chemicals. Tarnish doesn't show up overnight, but it does form over time. You'll notice that a decorative piece of silver turns from shiny silver to a dull gray color over a period of months, even though it's never moved from its position. Jewelry tends to tarnish a little more quickly due to its exposure to a variety of elemental conditions as it's worn. 

The Chemical Reaction Known as Tarnish

Tarnish is caused by a number of chemical reactions, and it takes little in the way of exposure to get the process started. Some of the chemicals that cause tarnish include:

  • Sulfuric gasses
  • Salt
  • Chlorine
  • Sweat 
  • Soaps and detergents
  • Bleach
  • Oxygen

It was long thought that oxygen was the major cause for tarnishing silver, but a study done by Gabriele Saleh and Stefano Sanvito at Trinity College, Dublin, discovered that hydrogen sulfide is the cause, not oxygen. The researchers got down to the atomic level of the tarnishing process to determine which chemical or substance caused silver to tarnish the fastest. In contrast, oxygen affects sterling silver at a much slower rate than hydrogen sulfide and other sulfurs.

The burning of fossil fuels is a major contributor to sulfur in the atmosphere. Emission regulations have greatly reduced the amount of sulfur that reaches the atmosphere, but it doesn't take a lot of exposure to sulfur to cause sterling silver to tarnish. What this means is that your sterling silver pieces, even ones that never leave the home, tarnish due to the fact that sulfur in its gaseous form is so prevalent in the atmosphere. 

Exhaust isn't the only thing that contributes to the creation of tarnish, however. Tissue paper, paper boxes, hair sprays, shampoos, and even food can create sulfuric gases that make your jewelry tarnish. In summary, it's difficult to prevent sterling silver from tarnishing because there are so many chemicals, natural and synthetic, floating around in the atmosphere and emitting reactive gasses. 

The Impact Tarnish has on Sterling Silver Over Time

The tarnish layer that forms on sterling silver won't cause permanent damage, but it does create an unsightly coating that obscures the beauty of your pieces. Tarnish tends to starts out as a light yellow color before turning to a different color. Eventually the entire piece black if it's not cleaned.

A single piece of sterling silver can have multiple colors of tarnish appear as it oxidizes. The colors are a reaction to the different types of gasses it's been exposed to, and won't hurt or otherwise impact your silver. You may notice that your piece starts looking yellow, then changes to a dark purple or blue before it turns black. 

The length of time it takes for a piece of sterling silver to tarnish depends on what it's been exposed to. For example, wearing a sterling silver ring and leaving it on while you wash and dry your hands serves to remove the oils and chemicals that create tarnish. However, if you take that ring off a while later and leave it sitting on a dresser or in a drawer for a long period of time, those same contaminants will cause the ring to tarnish. 

A sterling silver piece that's been left to sit for a long period of time without handling is eventually going to tarnish. You may not notice your piece is changing color at first, but you'll eventually be able to detect the difference as the piece dulls. It's good to be proactive when it comes to preventing tarnish from forming by engaging in regular cleaning routines. 

Ultimately, tarnish is a fact of life when it comes to sterling silver, even when engaging in preventative measures to stop it from showing up. The good news is that its appearance won't damage your pieces, and you can always remove the layer of tarnish, no matter how dark it gets.

Cleaning Tarnish From Your Sterling Silver Pieces

Cleaning the tarnish off your sterling silver pieces is easy and straightforward. You can use a commercial cleaner or make your own cleaner from ingredients that you find in your kitchen pantry. Other options include silver polishing cloths, ultrasonic or ionic cleaners, or chemical cleaners. 

As you clean off the tarnish, be careful of any stones and settings that are in the piece. You don't want to scratch or otherwise damage stones and bend prongs that hold stones in place. 

Homemade Cleaners

Weak acids such as vinegar and lemon juice do a great job of breaking up the tarnish and making it easy to rub away with a clean cloth or soft toothbrush. For more stubborn tarnish, add in a little baking soda to make a paste with a gentle scrubbing action.

When using a homemade remover, start by applying your tarnish remover to your piece and letting it soak in for a minute or two. The goal is to get the tarnish to get broken down by the remover and make it easier to wipe away with a cloth. You may need to repeat the application of a remover more than once, depending on how old the tarnish layer is and how thick it's become. 

Commercial Cleaners

 Most commercial cleaners work by applying the product to the piece, waiting for it to break up the tarnish, then wiping it off. All the tarnish and cleaner will come off onto the cloth but may require an additional rinse to get rid of any residue. 

If you're using a commercially made remover, follow the instructions for its use for the best possible results. Always check the label to make sure it's safe for use with stones. 

Silver Polishing Cloths

Silver polishing cloths are an alternative to using cleaners and water to remove tarnish, and work well for delicate pieces or jewelry that is set with stones. A polishing cloth is impregnated with a silver cleaning compound that breaks up the tarnish and pulls it off at the same time. You'll notice that your cloth picks up black streaks as you polish while leaving behind a clean piece of sterling silver that gleams once again. 

Once you're satisfied with the look of the piece, you can rinse it in warm water or run it under your faucet. Make sure that you've washed away all of your cleaner and there's no residue left behind. Take another towel to pat the piece dry, then let it sit out to dry the rest of the way. Any water spots left behind can be easily wiped away with a cloth. 

Ionic and Ultrasonic Cleaners

Both of these cleaners do an excellent job of removing tarnish from sterling silver, although an ionic cleaner tends to be more costly than the ultrasonic cleaner. The ultrasonic cleaner uses high-speed vibration to get rid of tarnish, while the ionic cleaner uses electrolysis. An ultrasonic cleaner works best on pieces that don't have stones, while the ionic cleaner can be used safely on pieces with stones of all types and hardness.

An ultrasonic cleaner uses a process known as cavitation to remove tarnish through the creation of high speed waves. The waves cause bubbles to form in the tarnish layer and break it up. The waves then remove the tarnish from the piece and the cleaning solution washes the piece clean.

In contrast, an ionic cleaner uses one or two clips that are connected to a battery pack and quietly removes the tarnish with an electric current. The process is similar to plating metal, but the solution used for ionic cleaning is one that cleans instead of plates. An ionic cleaning kit is more expensive than an ultrasonic cleaner, but it's a worthy investment, especially if you have a lot of jewelry pieces with stones. 

Wear Your Silver Jewelry Regularly

Wearing jewelry causes it to undergo gentle abrasion as it contacts your skin and clothes. This action keeps tarnish from developing because it's always in motion. For example, if you twist your ring on your finger, the surface of the ring is brushing against your skin and stops tarnish from forming. The trade-off is that you have to clean your jewelry to remove the build-up of debris. However, it's much easier to clean debris from your jewelry than tarnish. 

After you've cleaned your piece, you can wear it again, set it out on display, or put it away in a container or bag that prevents tarnish from returning. 

Ways to Prevent Tarnish From Taking Hold or Returning

There are a few options for preventing tarnish from discoloring your pieces apart from regular cleanings, and you can use any type of container that's convenient for your use. The goal of using a container is to protect your silver from coming into contact with airborne contaminants that cause it to discolor. Here are a few container types to get you started.

Plastic ziplock bags

A simple sandwich bag with a ziplock seal is perfect for small pieces of sterling silver such as rings pins, necklaces, and objects. The thickness of the plastic along with the locking seal keeps airborne chemicals from reaching your items, protecting it from tarnish for a long time. It's possible for a piece that's been stored in a plastic bag to tarnish, but it can be years before you see the silver turning dark. 

Adding an anti-tarnish strip or tab into the bag all but guarantees that your sterling silver will stay looking clean. The strips absorb and neutralize the gases that cause silver to tarnish. All you need to do is change out the tabs on a regular basis to keep your sterling silver clean. 

Airtight containers

An airtight container can be anything from a storage tub to a box with a seal around the edge of the lid. Look for a container that allows for minimal or zero airflow through the lid. They come in a range of sizes that make it easy to store your jewelry in a drawer or protect larger items for long-term storage. You can increase the anti-tarnish protection by putting the piece into a ziplock or anti-tarnish bag. 

Anti-tarnish storage boxes and bags

Look for storage boxes and bags that are specifically designed to protect silver pieces against tarnish. They're made from materials that neutralize tarnishing gases and won't damage the surface of your silver piece while it's being stored. Storage boxes with anti-tarnish properties are also an option, and allow you to safely store multiple pieces of sterling silver in one location. 

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