Since sterling silver is an alloy, it tarnishes when it comes into contact with sulfur particles, which are found in abundance in the air. For this reason, all sterling silver jewelry tarnishes, even silver-plated jewelry, according to Simply Sterling of Colorado. Lotions and perfumes may speed up the process.
Fortunately, it's possible to prevent sterling silver from tarnishing, a process that changes the color of the silver, through cleaning. Simply Sterling of Colorado recommends polishing jewelry with a silver polish cloth regularly. If a deeper clean is necessary, it recommends taking the piece to an experienced jeweler to be cleaned.