This is a beautiful vintage setting - octagonal with tiny claw prongs - holding a nicely cut oec moissanite.
It's currently a size 5 3/4. I wear a 6 1/4 and can wear this. The bottom of the band is somewhat ovoid and thin. It's also a bit out of round from decades of wear. It could easily have the lower 1/4 of the shank replaced but I just haven't bothered yet.
The stone is superb for an oec moissanite. No nail-head, lots of color, not green, just enough warmth for the cut and setting. There may be a flea bite or two but not visible to my naked eye.
Here is the listing that I purchased from: her description and photos are so much better than mine!
https://loupetroop.com/listings/rings-lab-created-center/8-dot-5mm-oec-moissanite-in-octagonal-edwardian-platinum-setting
Final sale please, confirmed Paypal only.