Our one of a kind, gold over sterling silver, handmade skulls smile more beautifully when they are well polished.
Sterling silver is made of silver and alloys. It’s 7.5% other metals, primarily copper, and 92.5% silver. Copper is added to silver to make it stronger and more durable. Copper, reacting primarily to sulphur in the air, is what makes silver tarnish. But, the copper can also react to a variety of other compounds. Hence, silver tarnishes faster in areas where there is greater pollution and higher levels of humidity, or even when contact is made with cosmetics.
Since there are so many variables in tarnishing, a piece of silver jewelry that didn’t tarnish in the past may suddenly tarnish a lot. Recently, a customer wrote, "Months ago I spoke to you about my most favorite earrings. I can't seem to prevent them from turning black where the silver part is...they never used to do this with other jewelry. Is there anything I can do so they don't need to be polished every time I wear them, like when they get wet in the shower, bath or swimming?"
The writer of the email lives on Salt Spring Island, off Vancouver Island and British Columbia. It’s extremely humid and the exposure to rain, ocean water, and showering all could be contributing to the oxidation issue. In arid New Mexico, where we live, tarnishing is not as much of a factor as someone who lives in a humid climate. Fortunately, for us, we can leave our entire collection of jewelry out in our gallery cases for months without a care about tarnishing, but unlike our concerned customer from Vancouver, that is not the case.
The metal used in the earrings is the same now as it was before. So, in conclusion something has changed in the environment. Photographic chemicals can tarnish jewelry, and even other harsh chemicals such as nitric acid or cleaning agents which create salt solutions which blacken the skin. Even changes in body chemistry can cause silver to tarnish. The skin contains thousands of perspiration glands. These glands emit enough fatty acids to actually cause a chemical reaction. The use of heavy antibiotics has also been known to create a reaction that darkens silver.
Another factor which can cause excess tarnishing is makeup. Makeup on the skin or clothing is the most common cause of the blackening or smudging. Interstingly enough, cosmetics often contain chemical compounds which are harder than the jewelry itself. Metallic abrasion occurs when these hard compounds, found in most makeup products, come in contact with the metal of the jewelry and wear or rub off very tiny particles of metal which appear as black dust.
Yet another factor in the tarnishing of silver is the silver itself. Some silver actually tarnishes more than other silver, depending upon whether the silver is actually sterling or not. Sometimes silver is stamped sterling silver but in fact is not really 92.5 percent. This cheaper silver can have more copper content, which causes greater tarnishing issues. A lot of silver coming out of Asia is actually stamped sterling but in fact is not sterling at all.
Cleaning Your Silver
In our shop, we intentionally oxidize our two tone gold over silver jewelry using a sulphuric compound. The silver is darkened or “antiqued” while the gold, which does not tarnish, provides a contrasting design element. In dryer climates, cleaning is not necessary as often. The best way to clean is to use a polishing cloth. Take note that using liquid cleaners will remove all the oxidation which will impact the two tone design.
One additional note on rings: some of our solid unique artisan gold wedding rings are also antiqued, and this darkened element is actually a finish that is painted on, rather than a natural chemical oxidation process. The coating is relatively permanent, but can fade due to exposure to bleaching agents, or simply because of wear over time.