These sterling silver disks are hand stamped and can vary slightly. For care of the silver charms, a polishing cloth and a quick dip in silver cleaner will do the trick. When not being worn, they can be stored in a zip-lock bag to slow down the tarnishing. Always be sure to put jewelry on after lotions/perfumes/sunscreens and not to wear in a pool or hot tub. Great gifts for grandmothers, mothers, children’s first necklace, best friends and graduation!