Gold will turn on some people. I have gold from 10 -24k and I figured it would be my cheapy stuff that turned, NOT! It was the 24k. My jeweler said it could be hormones or body acids. All I know is it does not happen all the time and it is my pricy stuff that loses it's shine. Another intresting thing. I doubt this would happen on the ship but I bought "stamped" gold once and it lost all of it's gold coloring in three weeks. I took it to my jeweler and was told the clasp was gold, the rest was washed. A sucker is made every minute.