FREE: New Size 6 Silver Tone Green Stone Ring

Sorry but I can't change the GIN once there are bids.

Here is the answer from the JIC site and you can read more of the FAQ's on the site:
Can my ring turn my finger green?

When a ring turns your finger green it's either because of a chemical reaction between acids in your skin and the metal of the ring or a reaction between another substance on your hand, such as a lotion, and the metal of the ring. There are several metals that oxidize or react with your skin to produce a discoloration. You can get a green ring around your finger from wearing a rings made using copper, brass, silver and even gold. The common green color is not harmful of itself, though some people experience an itchy rash or other sensitivity reaction to the metal and may wish to avoid exposure to the metal.

Another common culprit is silver, which is found in sterling silver jewelry, plating for jewelry, and as an alloying metal in most gold jewelry. Some rings are pure copper, while others have a plating of another metal over copper or the copper may be part of the alloy (e.g., Sterling silver). Acids cause the silver to oxidize, which produces tarnish. The tarnish can leave a dark ring on your finger. If you are sensitive to metals, you may see a discoloration from wearing a ring containing nickel, though most likely this will be a red ring and may be associated with inflammation.