It's a tale as old as time: You grabbed that cute ring on mega sale and you've been getting compliments on it all day. Then, when you take it off, it leaves a green stain in its place. Ew. The good news: While that mark may be initially alarming, it doesn't necessarily mean you have to give up on your favourite accessories.
That stain is usually a result of a metal in the jewellery reacting with your skin — or something on your skin, such as hand lotion. Copper is often to blame. When the acids on your sweaty skin (or in your lotion) cause copper jewellery to corrode, the process creates copper salts. These blue-green compounds can leave a mark on your skin in that iconic shade we call "Statue of Liberty Teal." Other metals can produce similar effects: The silver present in sterling silver — and used as an alloy in a fair amount of gold jewellery — can oxidise when it comes in contact with skin. This causes tarnishing and can leave you with a dark-green or black stain. Although these marks are often associated with cheaper jewellery, they can happen with the pricey stuff, too. But, stainless steel and white gold are usually immune.
You'll be happy to learn that the greenish tinge is totally harmless — unless you have a specific sensitivity to the metal that's causing it. In that case, you might get itchy. But, you certainly won't have to amputate your finger. Also, the stain isn't permanent; it'll usually disappear within a few hours, or faster if you use nail polish (or makeup) remover.
And, because it's safe, you can still wear that green-generating jewellery if you so desire. Because your skin is constantly renewing itself, the offending ring will stain it anew with every wear. But, there are ways of preventing that, such as painting clear nail polish on the inside of the ring — to keep it from making contact with your finger (there's even a fancy jewellers' version). The easiest way to prevent the stain, though, is just to avoid the metals or skin products that cause it. Taking your jewellery off before washing with soap will also reduce your chances of going green.
So, just because your earrings are turning you into a Ninja Turtle doesn't mean you have to give them up forever. And, hey, Pantone named Lucite Green one of the top 10 shades for the upcoming spring, so it looks like you're ahead of the trend anyway.