This necklace is made out of copper and waxed cotton cord.  Copper is a metal that is very prone to tarnishing, therefore I do not recommend getting this necklace wet.  Try to avoid wearing it in the shower or during your workout – those activities will quicken the tarnishing process.  I highly recommend getting a metal polish and protectant such as Brasso, Noxon 7, Malco Twinkle, etc. They are inexpensive, very handy (as they polish metals besides copper), and not only clean but also protect your metal from further tarnishing.