I have a mine cut platinum ring with 26 diamonds set around the main stone. I have had two antique dealers look at this and one told me that it could possibly be a Tiffany ring. I can't find anything online to support that information. Both dealers told me that the ring was made around 1915. No one can tell me what this ring might be worth because I don't live in an area that sells antique diamonds. I am certain that it's in platinum. There are no markings within the inside of the ring because the ring is so well worn.