Female hand with diamond ring and nails
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If you've ever taken off your favorite ring only to discover, to your horror, a dark green band of skin underneath, you're not alone. While it can be jarring and unexpected, worry not, as that green mark on your finger is harmless. It's not permanent, although it may take a while to fade but if you keep wearing the same rings, it'll likely come back until you find a solution.

Avoid Alloys

Precious metals such as gold or copper are almost always alloyed with another metal to provide extra strength and durability. Unfortunately, alloys containing copper and nickel can cause skin discoloration. Many people are allergic to nickel, and an allergic reaction can cause your skin to turn green or black. If your skin is particularly acidic, it can react with the alloy and also cause your skin to change color. Choose an alloy free of nickel or copper if possible. You can also try wearing a ring with a higher carat of gold -- 18 carat instead of 14 carat -- or switching to a platinum or stainless steel ring.

Swimming Hazards

Remove your rings before hitting the water. The chlorine in swimming pools can react with the metal of your jewelry and cause skin discoloration. What's worse, chlorine can eat away at both gold and silver rings, leaving them pitted and brittle. Saltwater can also cause reactions with gold and silver that result in greenish skin.

Chemical Cleaners and Cosmetics

Sometimes the chemicals in cosmetics such as body lotions can react with the metals in your rings. Another culprit may be the chemicals in certain household cleaners -- bleach and its high chlorine content is a big suspect here. Remove your rings before doing household chores just in case, and wash your hands thoroughly with mild soap and water before putting them back on.

An Ounce of Prevention

In addition to removing your rings when you'll encounter hazards such as chlorinated pools, you can take some easy preventative measures to keep skin discoloration at bay. Remove your rings when sleeping and clean your rings regularly to keep them free of dirt and perspiration. Mild dish soap and a soft cloth will do the job just fine.

Rhodium Coating

If simple prevention doesn't seem to work, you can have the insides of your rings coated with a protective layer of rhodium, which is a metal that forms a bright silvery barrier to prevent the chemical reactions that turn your skin green. For a quick fix, a thin coat of clear nail polish can help, but it'll flake off and need to be reapplied.