Why Jewelry Turns Skin Green and How to Stop It

A chemistry problem, not a skin problem

That green band under a ring is a chemical reaction, and it rinses off. It happens when copper in the metal meets moisture and mild acids on your skin. Sweat is slightly acidic and salty, and lotions, soap and hand sanitizer add their own ingredients. Together with oxygen in the air, they slowly react with the surface of the metal and form copper compounds, which are green. Those compounds rub onto your skin and leave the mark.

It is harmless. Soap and warm water take it off, and a cotton pad with a little rubbing alcohol shifts a stubborn patch. It is not, on its own, proof that a piece is fake or poorly made, although it does tell you there is copper close to the surface.

Which metals do it

Copper is the common ingredient. Pure gold and pure silver are too soft for most jewelry, so they are mixed with other metals, and copper is one of the most common. The less precious metal there is in the alloy, and the closer the copper is to your skin, the more likely a mark becomes.

• Copper, brass and bronze: the most likely by far. Brass is copper and zinc, and many costume pieces are made from it.
• Plated pieces with worn plating: fine while the plating is intact. Once it wears through on a ring palm, a clasp or the underside of a watch bracelet, the base metal touches your skin.
• 10K gold: under half gold, so marks are more common than with higher karats.
• 14K gold: 58.3% gold. Marks are uncommon but possible, especially for people with very acidic sweat. Our solid gold rings are 14K, so this applies to them too.
• 925 sterling silver: 92.5% silver, with the rest usually copper. A green mark is occasional; a gray or black smudge from tarnish is more likely.
• Stainless steel: very unlikely to leave a mark, which is one reason it is used for watch cases, including ours.

Why it happens to some people and not others

Two people can wear the same ring and only one ends up green. Skin chemistry varies, and so does habit. Heat and humidity make you sweat more. Pool chlorine and salt water speed up the reaction. Moisturizer, sunscreen and sanitizer trapped under a band keep the skin wet for hours. Rings are the worst offenders because a band holds that moisture against the skin all day, which is also why the mark is usually a neat ring shape.

Soap is another hidden cause. Washing your hands with a ring on leaves a film of soap under the band, and that film holds water. It can make the skin under the ring sore as well as discolored.

Green marks versus an allergy

A green stain does not itch or hurt. If the skin under a piece goes red, itchy, bumpy or flaky, that is a different thing: usually a contact allergy, and nickel is the most common culprit. It can appear a day or two after wearing, and it can get worse with each exposure.

Nickel turns up in some white gold alloys, in some base metals under plating and in costume jewelry. Stainless steel contains nickel too. Most people with a mild sensitivity wear steel without trouble, but very sensitive skin can still react.

Black marks have different causes

A dark gray or black smudge is usually something else. Sterling silver tarnishes, and the tarnish rubs off on skin. Makeup can do it too: powders and foundations containing hard minerals act like a very fine abrasive and wear tiny particles off gold and silver, which show up as a dark smear on skin or clothing. Cleaning the piece and putting it on after makeup has set usually solves it.

How to stop it

1. Put jewelry on dry skin. Let moisturizer, sunscreen and perfume soak in for a few minutes first.
2. Take rings off to wash your hands, or at least dry thoroughly underneath the band afterward.
3. Remove pieces for workouts, swimming, showers and hot tubs. Sweat and chlorine are the fastest route to a green finger.
4. Clean the metal regularly. Mild soap, warm water and a soft brush, then dry completely. Residue on the inside of a band holds moisture against your skin.
5. Add a clear barrier on the inside of a band. A jewelry barrier coating, or clear nail polish in a pinch, keeps the metal off your skin. Keep it off stones and settings, where it dulls the sparkle and traps dirt. It wears away, so reapply it every few weeks.

When it is time to replate

On a plated piece, a green mark that starts suddenly after months of clean wear usually means the plating has worn through at a contact point. A jeweler can strip, clean and replate it, which brings back the color and puts a fresh layer between the base metal and your skin. Rhodium Plating explains how replating works on white pieces. Solid gold and sterling silver do not need replating for this reason; a good clean is usually enough.

For more on how plating works and where it wears, read Gold, Silver and Plating Explained, and for routine cleaning see How to Care for Silver and Gold Jewelry.