Have you ever removed your well worn silver or gold jewelry and discovered the St. Patty's day green mark that it left behind? Well, there are very simple explanations for it and none of them have to do with the luck of the Irish or promise of money coming. Most jewelry is made of metals. Most of these metals are classified as transition elements (gold, silver, copper, etc.), which means they have varying levels of chemical reactivity. So, your beautiful necklace could be reacting to a number of chemicals that you are unaware of. The reason why certain jewelry turns your skin green could be the result of several factors:
The jewelry is not pure silver or gold.
Pure silver or gold (defined as at least 24k) takes longer to chemically react. Normally, if it does react it doesn't leave a green mark. Rather, it leaves a black smudge or gold or silver smudge. However, if it isn't pure, and is comprised mostly of copper or iron then it is more likely to create a green mark as a metallic reaction to the air or other substance.
Your body is secreting chemicals that strip down the metals.
Sweat, or chemical changes in the body can affect the metallic reaction of your jewelry causing a discoloration on the skin.
Your environment is affecting the state of your jewelry.
The salt or sulphur in the air, and chlorine can have a tarnishing affect on your jewelry which causes a stain.
You may have an allergic reaction.
It is not that uncommon to have reactions to certain jewelry. Because jewelry may be created from a variety of substances besides natural metals, there may be an underlying substance which is causing your allergic reaction. For example, some jewelry is made with traces of latex. If you are allergic to latex, this may be the culprit.
Makeup particles could be breaking down the metallic substances in your jewelry. Makeup particles that may fall from your face to your jewelry are actually abrasive to certain metals in your jewelry. If you have gold plated jewelry, the particles from makeup can scrub off the gold filling and expose the underlying copper in the jewelry. Once exposed, the copper can react to the environment or other factors to make it turn your skin green. (If it is pure gold, the reaction may be a black smudge or gold smudge).
There are many reasons why jewelry turns green. But one thing is true, it is the definitely the result of a reaction. Once you begin to test out each of these factors, you can figure out what it is and possibly how to prevent it. Otherwise, get prepared to make green colored skin the new fashion statement of the year.