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 1910s.
The stone is secured in a high four claw platinum collet with asymmetrical sweeping detail in the gallery, leading to diamond-set platinum shoulders to a slim, 18k yellow gold shank.

Accompanied a diamond grading report from HRD Antwerp (#180000077617).
Cut – Old mine cut in the centre (eight-cuts in the shoulders).
Colour – H (G to H in the shoulders).
Clarity – VVS2. (VS1 to VS2 in the shoulders).

Carat – 0.96. (with a further approximate 0.06 carat in the shoulders).
Circa – 1910.
Measurements – The diamond is 5.58 x 5.56mm. Sits 7.4mm from the finger .
Size – N 1/2 (UK) or 6.75 (US). Complimentary sizing is available, can go up or down.
Metal – 18k yellow gold and platinum. Tested.
https://www.gatsbyjewellery.co.uk/product/edwardian-0-96-carat-old-cut-diamond-engagement-ring-circa-1910/
Gatsby Jewellery Ltd has dated this piece to the 1910s.
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