Answers (1)
Sterling silver turns black or tarnishes due to a chemical reaction caused by contact with sulfur or hydrogen. Some foods or everyday items containing sulfur can cause tarnishing, but even polluted air can turn sterling silver black. It's tarnish--a sulfur reaction in the metal.
Use warm water to wash your jewelry items gently, and dry them with a soft cloth. You can also delay tarnishing by regularly polishing your silver jewelry. Use a polishing cloth to clean your silver items at the first signs of tarnishing.