Gatsby Jewellery Ltd has dated this piece to the 1920s.
The stone is secured in a hexagonal shaped platinum collect with Greek-key style pattern in the gallery, and sits on a slender 18k yellow gold shank which tapers at the shoulders.

Accompanied by a GIA Natural Diamond Report. The GIA number is inscribed on the diamond providing utmost security.
Cut: Old European.
Colour: E.
Clarity: VS1.
Carat: 0.90.
Circa: 1925.
Size: N (UK) or 6 1/2 (US). Free sizing available.

Measurements: The diamond is 5.92 x 6.06 and sits 6.3mm from the finger.
Weight: 3.30 grams.
Metal: 18k yellow gold and platinum. 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/antique-0-90-carat-old-cut-diamond-engagement-ring-circa-1925
Item # 5131013S175
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