One of the best advice to keep the luster and beauty of costume jewelry is to keep them clean and dry. Whether it is a ring, bracelet or earrings, exposing fashion jewelry to any type of cream, chemical product, lotion, perfume, oil or even water is an undeniable accelerator of tarnishing. Metals like brass, copper or bronze will oxidize and see their color changing (verdigris) gold platings will chip. So make sure to always remove your jewelry before applying cream, perfume or when you wash your hands. It is also very important in order to limit the greenish traces that some costume jewelry leave on the skin.
Fashion jewelry is usually not meant to be worn every day. Therefore, if you wear the same pieces of jewelry on a daily basis, you might see discoloration coming quickly. To preserve the life of your jewelry, change it as often as possible by varying the outfits.
It is also important to remove them at the end of the day. Never go to sleep with fashion jewelry on, it is a sure way to damage it, to make it tarnish more quickly or even break it.
Clean them or at least wipe them down with a soft cloth to remove any product residues and sweat that accelerates oxidation. Avoid at all costs cleaners that contain acid.
In jewelry boxes, pouches, loose in a drawer.