Magnetic Field Therapy ✦ Balance the physiological magnetic field of human body, improve the sub-health state, help to relieve arthritis, joint pain, RSI, carpal tunnel, migraine, reduce fatigue and muscle tension, promote relaxation and improve sleep quality. Tibetan 100% Pure Raw Copper healing rings are great for finger joint pain and swelling. The copper helps relieve tendon pain and improves circulation. For those unfamiliar with wearing copper jewelry, copper always tarnished and always marks the skin to a certain extent. The amount depends on several factors, such as how acidic your skin is and how much you perspire. Thats the property of pure copper. However if you are concerned about the stains caused in your finger by this ring you can clean the ring to remove the tarnish and then paint it with clear nail polish or regular topcoat. 4.We at recommend not to apply any polishing and wear it as is for ring to work properly for Healing purpose. You can always wash your finger with mild soap and warm water to get the stain off.