It was listed by Gatsby Jewellery Ltd. Sold pieces stay on Sellingantiques as a record of what has passed through, and the next one is rarely far away.
Gatsby Jewellery Ltd has dated this piece to the 1900s.

Contemporary hallmarks. London.
Cut – Old mine / miner cut.
Colour – H.
Clarity – VS2.
Carat – 0.59.
Circa – The diamond is circa 1900, the mount in new.
Size – M 1/2 (UK) or 6.25 (US). Complementary sizing is available, can be sized up or down.
Measurements – The diamond is 5mm in diameter and sits 6.1mm from the finger.
Metal – Platinum. Hallmarked.
Gatsby Jewellery Ltd has dated this piece to the 1900s.
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