Stone: Herkimer Diamond Metal: Copper Please allow for variation in stone size, shape and inclusions as all pieces are one of a kind and handmade Our rings are sealed with a jeweler grade sealant, which helps to reduce the natural patina process and the likelihood of your skin turning green. Everyone's body chemistry is unique, and some might experience discoloration on the skin when wearing a piece of jewelry (even if it has been sealed). This is a natural, harmless reaction called oxidation which happens when your body’s chemistry and oils combine with oxygen to create a layer of copper carbonate on top of your skin. If this happens, this is not a sign of a copper allergy, as it is rare to be allergic to copper due to its antimicrobial properties. It is best practice to remove jewelry before swimming, washing hands etc, as chemicals can be harmful to your jewelry.