I want to apologize, because I cant see the stamp I took them to the jeweler. They are not stamped. I am so sorry, when I bought the rings I was told one is platinum, the other sterling silver. I checked my other rings and had no problem finding the 925 stamp. The platinum ring I've had for 2 years, it has never turned nor my finger. They are beautiful rings though.whomever wins the platinum I will also send my stamped sterling silver.or bids may be canceled. Again I'm sorry..