All silver-plated jewelry tarnishes at some point, as the chemicals from daily wear and the exposed layer of silver react with air to change the color of a piece. Silver-plated jewelry has a very thin layer of silver that covers a non-precious base metal. Because the coating is so thin on the base, cleaning needs to be careful but complete to keep up an item's shine.
You will need a silver polishing cloth and then just pass the silver plated parts of the jewelry through the cloth rubbing and the shine will be restored.
This applies ONLY to silver plated jewelry. Gold and rose gold plated cannot be polished and should not be polished. For longer lasting wear please follow the tips bellow.
Humidity encourages tarnishing, so always store silver-plated jewelry or any other plated jewelry in a cool, dry place. A simple plastic re-closeable bag will work wonders, keep items dry in separate compartments while also helping to avoid scratches.
Letting an item sit for too long in water could cause corrosion of delicate parts on some jewelry. Always take off your silver-gold-rose gold plated jewelry before swimming, showering or cleaning as well as when putting on make up or using hair care products or perfumes. The water and chemicals used during these activities could cause the item to tarnish more quickly. Anti aging facial skin care products are acid based and should be avoided touching your jewelry (as in with a necklace) even if they are dry. A vitamin c cream or glycolic acid cream or retinol product may tarnish your items in a way that is not removable or it may expose the base metal. Use these products at night to avoid them damaging your plated and fine jewelry.