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 1930s.

Cut – Cushion cut sapphire and old mine cut diamonds.
Colour – The diamonds are G to H.
Clarity – The sapphire is loupe clean. The diamonds are VS1 to SI1; all are clean to the naked eye.
Carat – The sapphire is approximately 4.00 carat, with approximately 1.50 carat of diamonds.

Circa – 1930.
Size – P (UK) or 7.5 (US). Complimentary sizing is available, can go up or down.
Measurements – The sapphire is 9.3 x 6.3mm. The head of the ring is 18 x 13.9mm and sits 7.5mm from the finger.
Metal – 18k rose and white gold. French hallmarks.
https://www.gatsbyjewellery.co.uk/product/art-deco-4-00-carat-natural-ceylon-sapphire-old-cut-diamond-ring-french-circa-1930/
Gatsby Jewellery Ltd has dated this piece to the 1930s.
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