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

Cut – Old mine cuts.
Colour – H.
Clarity – SI1.
Carat – The bottom diamond is approximately 0.25 carat, the top is approximately 0.20 carat.
Circa – 1915.
Measurements – From the top of the top diamond to the bottom of the bottom diamond is 9.9mm.
Metal – The chain (which is a later replacement) is hallmarked 18k yellow gold. The pendant is 15k yellow gold with a platinum edge around the diamonds (tested).
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.
You can view the stock and full dealer information on the Gatsby Jewellery Ltd Profile Page