To help your jewelry last a long time while looking its best, take it off before you go to bed, and especially when swimming or bathing. This will prevent scratching, wear and tear on delicate chains and gold fill items, and oil and dirt build-up.
Sterling silver will eventually tarnish with normal wear. Gold fill may also tarnish, but at a much slower rate. To clean, gently wipe with a jewelry polishing cloth, or clean with a soft toothbrush and gentle soap and water. Any jewelry with an oxidized (black) or stone element should not go into chemical jewelry cleaning solution or ultrasonic cleaner.
Bronze jewelry will develop a rich gold patina over time. If this is not to your taste, you may restore shine with Worchestershire sauce! Dip the piece into the sauce for a minute, then thoroughly rinse in water. The acidity of the sauce will help remove tarnish. You can also maintain the finish of your bronze jewelry by washing it frequently with soap and water, which removes the body oils that facilitate oxidation.
Gemstones and pearls will slowly accumulate body oils and become dirty. Use a non-abrasive soap and water to wash them gently with your fingers. Do not use a polishing cloth on the surface of stones or pearls.