Gatsby Jewellery Ltd has dated this piece to the 1940s.
The stone is secured in a six-claw platinum collet with decorative scroll detailing in the gallery, leading to a slender 18k yellow gold shank.

Accompanied by a Diamond Report from IGI (#575300308).
Cut – Old mine cut.
Colour – I.
Clarity – VVS2.
Carat – 0.99.
Circa – 1940.
Size – L 1/2 (UK) or 5 7/8 (US). Complimentary sizing is available, can be sized up or down.
Measurements – The diamond is 6.12 x 5.68mm. Sits 6.7mm from the finger.
Metal – 18k yellow gold. The diamond is set in platinum. Tested.
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