Thanks so much for your input! Yes, it is platinum. I have had the prongs checked and the jeweler said they were in decent shape, w metal still covering the top of the diamond. Its amazing how well made these rings were- my grandmother wore it daily for 70+ years!It's still hard to see clearly but I'm going to guess that it is an OEC...but maybe with a slightly larger table than usual? I see a what looks like a small open culet and flowery facets under the table but that could still be a transitional.
I would not want to guess at ct weight without at least measurements of the top of the diamond. It could only be a guess/estimate at best unless you have the diamond unset.
Is the ring platinum? If you haven't already I would take it to a jeweler to check those fishtail prongs. Some of them look a bit flattened and that can happen with wear. You definitely do not want to lose such a precious heirloom!
It is beautiful.
I hope someone with more experience (and maybe younger eyes!) will chime in if I'm incorrect.
Interesting, I would have guessed a little over a carat. It looks big to me. It’s very pretty!Hard to accurately say because difficult to guesstimate depth/length of diamond bc of the setting... but seems to be about 5.5 mm across. Im guessing its about