The most common reason your finger gets discolored when wearing a gold ring is ‘metallic abrasion’. This is caused by makeup, or other cosmetics, on the skin. Cosmetics contain compounds that are harder than the gold (remember gold is soft). So the makeup will rub off very tiny particles of the metal. Very small particles of metal appear black in color rather than metallic, so it looks like black dust. When this dust comes in contact with surfaces that are absorbent, such as your skin or clothing, this dust sticks and forms a black smudge.
Another reason that that your finger may discolor is corrosion of the metals in your ring. The gold does not corrode, but the alloys that are mixed with the gold. (Remember, 14K gold means the ring has 58% of pure gold and 42% of non gold alloys.) The alloys that can corrode are silver and copper based, and they can form dark chemical compounds under moist conditions.
When you sweat, fats and fatty acids are released which can cause corrosion on your gold ring. This problem is worse in semi tropical locations (like when you go on vacation to Hawaii) and near the ocean where salt is in the air.
A third reason is chlorine in your pool or spa. Chlorine will eat away at gold and the alloys. So if you are wearing your rings in the spa or pool corrosion is happening. Ring turning black from gold ring.
How to prevent the discoloration:
Metal abrasion - Try switching cosmetics and see if the problem goes away. Remove your rings and jewelry while applying cosmetics. Then wash your hands to remove any makeup residue before you put on your jewelry.
Corrosion of metals - If you are in an area that is causing you to sweat, remove your jewelry often and use an absorbent powder (make sure it does NOT have abrasives in it) on your fingers or any part of the skin that has jewelry on it.
Remove rings before using soap, cleaning compounds and detergents. Clean your rings often.Concerning cleaning, we can send you a free polishing cloth. If every once in a while she ran the cloth around the inside of the band, it should take care of the problem.Please let us know if you have any additional questions.