Gatsby Jewellery Ltd has dated this piece to the 1900s.

Cut - Old European cuts
Colour - All stones are a matching H
Clarity - The large stone in the centre is VS. Some of the smaller stones are SI, but all diamonds are eye-clean.
Carat - 0.65 in the centre with a further 12 diamond of around 0.10 carat each. Total approximate diamond weight of 1.85 carat

Circa - 1900.
Condition - The platinum on one side of the halo has taken a little bit of a bump, though the diamonds themselves are undamaged.
Size - Currently M (UK) or 6 (US). Complementary sizing is available, can go up or down in size.
Measurements - The cluster measures 15.65mm by 14mm and sits 6.45mm from the finger.
Metal - 18k gold. The diamonds are set in platinum. Tested.
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