Every jeweler has encountered it, and every jewelry customer wants to know how to eliminate it. Here are a few tips you should know about dealing with the tarnish on your jewelry.
What is Tarnish?
Unfortunately, tarnish is an inevitable occurrence with any metal except gold and platinum. But what causes it? Tarnish is actually the result of a chemical reaction between the metal and sulfur in the environment. Sulfurs react with metal, physically breaking down the topmost layer of the metal in a process called “oxidation”. This thin layer of oxidation appears as a discoloration on the metal known as tarnish.
The color and rate of appearance of tarnish can vary widely and depends on the particular metals involved, the environment around the jewelry and the length of time the tarnish has built up. For example, sterling silver jewelry is often quick to tarnish, while more pure silvers react slower. Slower still is Argentium® Silver, which contains germanium as part of the alloy. Germanium forms a protective barrier that shields the metal from sulfurs in the environment, and therefore imparts a high tarnish-resistance to Argentium. It also appears that any tarnish that does occur on Argentium is easier to remove than from some other metals.
The environment you keep your metal jewelry in will also affect the rate of tarnish. High temperatures and high humidity are known to speed the tarnishing process.
How Can Tarnish Be Prevented?
Unless you're working with gold or platinum, tarnish can never be completely prevented. But there are several measures a jeweler can take to slow the rate of tarnish. First, control your jewelry’s environment. Keep your jewelry in a cool, dry place. If you live and work in an area with high temperatures and high humidity, this may be a little harder to accomplish, but measures such as anti-tarnish strips placed in your jewelry case can help reduce the gases and humidity in the environment that cause tarnish. Silver-Guard™ anti-tarnish blocks (#400-640) are useful for display cases—just place them behind displays, hidden from view. You can also place 3M Tarni-Shield™ tabs (#337-540) or strips (#337-541) inside zipper bags.
Another option is to dip your jewelry piece in clear lacquer to isolate the metal from the environment. While this is effective, it is not suited to all jewelry, and the lacquer will eventually wear off.
How Can Tarnish Be Removed?
Tarnish is usually removeable, although this depends on the depth and severity of the tarnish. Remember, tarnish is actually the remnants of oxidized metal—the only way to remove it is to physically remove the layer of damaged metal. Sunshine® cloths (#337-013) are great for removing tarnish from a variety of metals, including silver, brass, copper, bronze and more. There is also a Sunshine® cloth made especially for treating stainless steel (#337-014). Other tarnish removers are also available, and many are available in liquid or spray form. The effectiveness of any tarnish removal treatment depends on the depth and type of tarnish. The yellowish tint that tends to form on silver is easiest to remove, while deep blue tarnish is harder to remove, as it usually indicates a deeper degree of tarnish. Many different chemical reactions are responsible for the wide variety of tarnish you may encounter, and you’ll need to experiment to find which treatments work best.
