Gatsby Jewellery Ltd has dated this piece to the 1920s.
The stone is secured in an eight claw coronet collet which sits nice and low to the finger. Six (three each side) old cut diamond are set in each shoulder, leading to a slim and slightly knife-edge shank. All in platinum. Currently UK size K, US size 5 1/8 (complimentary sizing available).

Accompanied by a De Beers Institute of Diamonds grading report (#010000277505). A unique number has been inscribed on this diamond providing utmost security.
Cut – Old mine cut (and old mine cuts in the shoulders).

Colour – I (the diamonds in the shoulders range from H to I).
Clarity – SI2 (this diamonds in the shoulders are VS2 to SI1).
Carat – 0.62 (with a further approximate 0.12 carat in the shoulders).
Circa – 1920.

Measurements – The centre diamond is 5.48 x 4.94mm. Sits 4.3mm from the finger.
Size – K (UK) or 5 1/8 (US). Complimentary sizing is available, can go up or down.
Weight – 2.26 grams.
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.
You can view the stock and full dealer information on the Gatsby Jewellery Ltd Profile Page