Please keep in mind that metal, when it comes in contact with air or the oils of your skin, does tarnish or darken. Darkened metal is a natural process and it depends on each individual person how long it will take before your piece tarnishes.
It can be brought to shine again by polishing with a silver cleaning cloth. Cleaning cloths often are available in good groceries or a jewelry shop.
I recommend that customers remove jewelry before going to bed, taking a bath or shower or participating in physical activity.
Exposure to certain harsh chemicals or environments will result in compromising the integrity of your jewelry. This includes, but is not limited to the following: perspiration, perfumes, cleaning agents, chlorine and salt water.