Gatsby Jewellery Ltd has dated this piece to the 1920s.
The stone is secured in an eight-claw coronet collet which sit on a slim and tapering shank. All in 18k gold.

Accompanied by a GIA Natural Diamond Report. The GIA number is inscribed on the diamond providing utmost security.
Cut: Old European.
Colour: H.
Clarity: SI1.
Carat: 0.55.
Circa: 1920.
Size: M 1/2 (UK) or 6 1/4 (US). Free sizing available.

Measurements: The diamond is 5.47 x 5.49mm and sits 5.3mm from the finger.
Weight: 1.85 grams.
Metal: 18k gold. Tested with a Niton DXL Precious Metal Analyzer.
Video: To view videos of this ring recorded in daylight, please either contact us or copy / paste the following link into your browser: https://gatsbyjewellery.co.uk/products/art-deco-0-55-carat-old-cut-diamond-engagement-ring-circa-1920
Item # 912813S026
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.
You can view the stock and full dealer information on the Gatsby Jewellery Ltd Profile Page