Gatsby Jewellery Ltd has dated this piece to the 1920s.
The stone is secured in a four claw yellow gold collet and sits on a slim, knife-edge 18k yellow gold shank.

Accompanied by a sapphire report from The Gem & Pearl Laboratory stating the sapphire shows no evidence of heating, and is Sri Lankan (Ceylon) in origin.
Cut:? Oval.
Carat:? 3.31.
Condition:? There is no external damage to the sapphire. However, it is worth noting that this is an old stone with a wonky shape which is why the stone doesn't look straight in some pictures.

Circa:? 1920.
Size:? L (UK) or 5 1/2 (US). Free sizing available.
Measurements:? The sapphire is 9.9 x 7.8mm and sits 6.1mm from the finger.
Weight:? 3.11 grams.
Metal:? 18k yellow gold. Tested with a Niton DXL Precious Metal Analyser.
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