Has gold and other jewelry ever left greenish or black marks on your skin? It happens to most of us at least once or twice, and even though some people are allergic to certain materials, most staining isn’t caused by an allergy–it’s a reaction between our skin and the metals used in jewelry, especially when the jewelry touches areas that perspire.

Copper Jewelry
Copper reacts to make skin green. The piece you’re wearing might not be pure copper, but it might have enough copper in it to cause a reaction, and some people seem to have body chemistry that’s prone to staining.

Sterling Silver
Sterling silver is 7.5 percent copper, but the most common stains from sterling silver jewelry are black, and occur when the metal tarnishes (darkens due to a reaction with gases in the air).
Some sterling pieces are coated with products that help keep them from tarnishing, but the coatings will wear off over time.

Nickel Allergies
If you are allergic to nickel, you won’t just have stained skin. Jewelry that contains this metal will make your skin itchy and red where it comes in contact with your body.