Gatsby Jewellery Ltd has dated this piece to the 1920s.
The diamond is secured in a four claw collet with a pair of (approx.) 0.10 carat tapered baguette cut diamonds set in the shoulders, leading to a slim platinum shank.

Accompanied by a Natural Diamond Grading Report from HRD Antwerp (#210000182399).
Cut – Old mine cut in the centre with tapered baguette cuts in the shoulders.
Colour – I in the centre (G to H in the shoulders).

Clarity – SI1. (VS1 to VS2 in the shoulders).
Carat – 1.25 (with an additional approximate 0.20 carat in the shoulders.)
Circa – 1925.
Size – L (UK) or 5.5 (US). Complimentary sizing is available, can be sized up or down.
Measurements – The diamond is 6.38 x 6.23mm and sits 7mm from the finger.
Metal – Platinum. Tested.
Gatsby Jewellery Ltd has dated this piece to the 1920s.
Gatsby jewellery are a husband and wife team who have years of knowledge and experience in dealing in fine antique jewellery.
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