It was listed by Gatsby Jewellery Ltd. Sold pieces stay on Sellingantiques as a record of what has passed through, and the next one is rarely far away.
Gatsby Jewellery Ltd has dated this piece to the 1940s.
The stone is secured in a fine, white gold collet with six double claws and hooped detailing in the gallery, leading to a slim and tapering yellow gold shank.

Accompanied by an independent jewellery report by IGR (#30307822).
Cut – Old mine cut.
Colour – Light yellow (N).
Clarity – SI2; the diamond is clean to the naked eye.
Carat – 0.69.
Circa – 1940.
Size – M 1/2 (UK) or 6.25 (US). Complimentary sizing is available, can go up or down.

Measurements – The diamond is approximately 5.25mm in diameter and sits 6.7mm from the finger.
Metal – 18k yellow and white gold. Tested.
https://www.gatsbyjewellery.co.uk/product/art-deco-0-69-carat-old-cut-diamond-engagement-ring-circa-1940/
Gatsby Jewellery Ltd has dated this piece to the 1940s.
Gatsby jewellery are a husband and wife team who have years of knowledge and experience in dealing in fine antique jewellery.
You can view the stock and full dealer information on the Gatsby Jewellery Ltd Profile Page