We make all of our jewelry (with the exception of custom pieces) with .925 Sterling silver, 14K Gold Fill, and occasionally brass sheet metal.
ALL fine metals will tarnish over time. Some metals will tarnish more quickly on people with an acidic body chemistry, there is no way for us to know before hand how quickly a metal will tarnish on any one person. It is best to store your jewelry in a dry area away from chemicals and especially not in your bathroom.
If you wish to polish your pieces we recommend using warm water with some lemon or lime juice and buffing with a scratch free cloth.