Sterling silver is considered as a precious metal with an alloy of 92.5% silver and 7.5% other base metals. Sterling silver will oxidize over time. You can restore its luster with a polishing cloth.
Metals tend to lose their luster over time. You can minimize tarnishing by wiping the jewelry with soft cotton cloth after each use and storing it in an airtight plastic bag. When you are storing it away for an extended time, consider placing a piece of chalk or a silica gel in the bag to further prevent tarnishing.
For daily use, avoid wearing your jewelry in the shower, pool, and the ocean as the humid environment can expedite tarnishing. All metals, including bronze, silver, and gold can react to cosmetics and cleaning products. Avoid contact as much as possible with perfumes, hairsprays, lotions, and household cleaners. As prone to tarnishing metals are, you can easily restore their luster by gently cleaning them with the polishing cloth provided to you.
*Directions for polishing: rub the surface to be polished with medium pressure until the cloth is completely darkened. Do not wash the cloth.