We use sterling silver, which is 92.5% pure silver and 7.5% copper which is the standard percentages for sterling silver metal. Sterling silver may react to extended use of hand sanitizer, which differs from person to person. Sterling silver jewelry will be sent with a polishing pad, you can polish and shine your jewelry with the provided polishing pad. Sterling silver typically tarnishes over time, and although it can be worn in water, the more moisture and water the metal is exposed to the quicker it can tarnish. Keep in mind, the tarnish can easily be removed with the polishing pad.