Gatsby Jewellery Ltd has dated this piece to the 1910s.

Accompanied by an independent jewellery report from WGI.
Cut: Old European cut.
Colour: G to H.
Clarity: VS2 and SI1.
Carat: A combined weight of approximately 1.20 carat.
Circa: 1910.
Size: M or US size 6. Free sizing available.

Measurements: From the outer edge of one diamond to the other is 10.7mm. The ring sits 6mm from the finger.
Weight: 2.67 grams.
Metal: Stamped 18CT. Tested with a Niton DXL Precious Metal Analyzer to confirm.
co.uk/products/antique-1-20-carat-old-cut-diamond-toi-et-moi-ring-circa-1910
Gatsby Jewellery Ltd has dated this piece to the 1910s.
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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