Gatsby Jewellery Ltd has dated this piece to the 1930s.
The stone is rubover set in platinum and is flanked by by four (two each side) baguette cut diamonds which step-up from the corners of the emerald. The confident and geometric arrangement of the stones is immediately evocative of the Art Deco era.

Accompanied by a report from Gemmological Certification Services (GCS) stating the emerald is Russian and has only received minor clarity enhancement.
On an 18 inch platinum trace chain.
Cut – The emerald is a rectangular step cut, and the diamonds are baguette cuts.

Colour – The diamonds are H to I.
Clarity – The diamonds are VS2 to SI2.
Carat – The emerald is approximately 5.70 carat. The larger diamonds are approximately 0.35 carat each, the smaller are approximately 0.20 carat each – so an total approximate diamond weight of 1.10 carat

Circa – 1930.
Measurements – The emerald is approximately 11 x 9.5mm. The pendant is 23mm across at the widest point and is 14.7 and the longest point (not including the bales).
Weight – 9.35 grams
Metal – Platinum. Tested.
Gatsby Jewellery Ltd has dated this piece to the 1930s.
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