Time for a swim. NOT WITH YOUR JEWELRY ON!!!!! Pool water is one of the worst things for your jewelry. Most gold and silver jewelry has alloys in the metal. This is what chlorine loves to attack. Those pretty little prongs holding that beautiful diamond in place become weak and brittle from the chlorine. Therefore, this means more chances for them to break off. As you can see in this picture the one prong is broken.
In the case of silver, it will turn black from the chlorine. Platinum (and its family members like Paladium) are not effected by chlorine but that is not to say the gemstones are not. Diamonds are strong and won't be damaged by the chlorine, but other gemstones may not fair quite so well. For example pearls are a very porous gemstone. Therefore, chances are, your pearl will change color from the pool water.
A great idea is to have your jewelry checked now. Bring it in, we can check the prongs, clean them up and have them perfect for all of the holiday parties this weekend. With Memorial Day quickly upon us, pools will be opening all over. Truth is you have invested time and money into picking out that perfect piece of jewelry. Take off your jewelry before swimming, put it in a safe place and go have fun!