Gatsby Jewellery Ltd has dated this piece to the 1950s.
Utterly gorgeous.

Accompanied by a Natural Diamond Grading Report from HRD Antwerp (#210000182336).
Cut – Old European cut in the centre with round brilliant cuts in the surround and down the shoulders.
Colour – I. (G in the surround.)

Clarity – VS2. (VS1 to VS2 in the surround.)
Carat – 1.38 in the centre with a total approximate diamond weight of 2.01 carat.
Circa – 1950.
Size – J (UK) or 4 5/8 (US). Complimentary sizing is available, can go up or down.
Measurements – The diamond is 6.68 x 6.71mm. The head of the ring is 13.25 x 13.25mm and sits 6mm from the finger.
Metal – Stamped PLAT – indicating platinum – and tests as such.
Gatsby Jewellery Ltd has dated this piece to the 1950s.
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