Gatsby Jewellery Ltd has dated this piece to the 1960s.

Accompanied by an independent jewellery report from IGR (#30309460).
Cut – Old mine cut.
Colour – G.
Clarity – VS2.
Carat – 0.62
Circa – 1960.
Size – L 1/2 (UK) or 5 7/8 (US). Complimentary sizing is available, can be sized up or down.
Measurements – The diamond is 4.75 x 5.2mm. Sits 6.9mm from the finger.
Metal – Platinum. Tested.
Gatsby Jewellery Ltd has dated this piece to the 1960s.
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