How to care for your jewelry. -Keep away from perfumes. -No Hairspray or Serums. -Store every piece of jewelry in a separate Bag. -Use a washcloth to gently clean the jewelry. -Water can tarnish and rust costume jewelry if it sits for too long. It's usually not a good idea to let imitation jewelry soak in water for a long time as it can ruin the look or finish of the jewelry.