I don't know much about it. Less than an inch in every direction.
Thank you for contacting Mearto with your appraisal inquiry.
It is a beautiful antique ring. Such antique jewellery are being offered at auction on a regular basis.
From the design and ornaments I would say that the ring is from the 1900s more specific around the 1930s. The material is probably whitegold or perhaps even platinum which was the preferred materials at the time. The front is set with a diamond. From the photos it is hard to tell the size of the diamond as well as the colour and clarity, however the design and overall impression of the ring is good. It looks as if it has some scratches and marks after having been used however nothing unexpectable given the age of the ring.
I believe that this ring would attract the attention of both collectors and dealers if it came up for auction.
The estimate provided is for a well-advertised specialised online jewellery auction, where I believe the diamond ring has the best chance of realising its fullest potential. However, there is no measurement for the sentimental value you might attach to the ring. Retail "asking prices" can be higher and vary.
Please let me know if you have any additional questions. I’m happy to help.