Silver-filled, solid silver, 14k gold-filled, and copper jewelry:
They will naturally continue to darken over time. To keep your jewelry looking bright and shiny, you can either use a polishing cloth or some soap and warm water with some fine steel wool then make sure to dry thoroughly.
Wire jewelry is very fragile! So, to keep from distorting it with bends and scratches, always handle your pieces with care and store in a safe place.
Tips: Keep away from essential oils, household cleaners, do not wear your jewelry whilst swimming, playing sports, showering, bathing, or sleeping.
Keep It Shiny Pro Tip:
To slow oxidation process, store you jewelry in a plastic bag away from any humidity, heat, and the sun!