Thank you for contacting Mearto with your appraisal inquiry.

It is a beautiful vintage ruby and diamond gold ring. Such vintage jewellery are being offered at auction on a regular basis.
The design of the ring is very special and elegant. The two large rubys surrounded by numerous diamonds makes the ring very impressive. The design of the ring is typical of the 1970s-1980s when this ring was probably made and designed for your grandmother. The 18 kt gold ring has a lovely shape.
As for the stones it is hard to tell the exact size and clarity. You state that the 2 rubys are 1 kt each and that information has been used for the appraisal.

I believe that the 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 lovely ring has the best chance of realising its fullest potential. However, there is no measurement for the sentimental value you might attach to the unique ring with diamonds and rubys. Retail "asking prices" can be higher and vary.

Please let me know if you have any additional questions. I’m happy to help.
Thank you