Disclaimer: Rings that contain significant amounts of certain metals like copper, brass, nickel, etc., often found in circulating, clad coins or coins with low silver content, may result in allergic reactions for some people. One of the more frequent reactions is commonly known as “green finger” where the ring causes a slight discoloration of the skin—green or black marks where the ring makes contact with the skin. Some people could also experience skin irritation such as redness of the skin, swelling and/or itching. Some people minimize or even eliminate these issues by simply coating the inside of their ring with clear nail polish or some other type coatings. Modern Hill is not responsible for any damages due to allergic reactions that may result from wearing our rings or other products. Some people could have reactions to virtually any type metal, but if you are concerned about potential reactions to these type metals, then it is best to consider rings with very high (90% or greater) silver content to reduce the potential of skin reactions—we sell several very nice coin rings with high silver content to minimize the potential of green finger, irritation, etc., that could result from wearing clad, or low silver content, jewelry. However, please understand, all these rings are made from coins—coins were not intended to be worn as rings, so virtually any coin ring, regardless of silver content could result in various skin issues. If you are concerned about this potential, then please DO NOT buy these rings—skin problems are between you and your dermatologist, I am not a dermatologist. thank you for everything.