I don't know the specific effects, if any, on a diamond, but my jeweler does not recommend swimming with any jewelry on. He stated that chlorine has an effect on gold but did not report any effect on the diamond. I would just be afraid to lose the ring in the water. In the water, your fingers shrink, so it is easier for a ring to slip off. When I was on my honeymoon I did wear my diamond and wedding band in the water in fear that someone would steal them if they were not on me. At the end of the trip between the salt water and chlorine, my diamond was soooooooooooooo cloudy! It definitely needed a major cleaning. Just another tip, I wear my wedding band on top of my ering if I wear them in the water to secure the diamond on my finger. Just a tip I learned from a friend. However, I have many friends who swim with their erings on without worry. Whenever I am able to, I remove my rings when going into chlorine pool. Hope this helps a little. I really would also like to hear what others have to say.
