All jewelry tarnishes (turns black /dulls/ oxidizes)
This is not rust, and is still safe to wear.
In addition to tarnishing, all plated jewelry will fade or change color.
★ Aim to minimize contact between your skin and the jewelry
(wear over your clothes etc)
★ Do not wear your jewelry to bed, in the shower, at the beach/pool etc
★ Keep away from perfumes and body lotions, especially sunscreen
★ Use a dry jewelry polishing cloth to shine and clean after EACH WEAR.
(Jewelry cloths are fairly inexpensive and last for years)
★ Store away from sunlight, dampness and open air.
Best way to store them is in the re-sealable baggie they come packaged in.