Gatsby Jewellery Ltd has dated this piece to the 1940s.

Cut - Oval cut fire opal. The diamonds are single cuts.
Colour - Diamonds are G.
Clarity - All stones are VS.
Carat - The opal is estimated at 5.00 carat. The total approximate diamond weight is 0.20 carat

Circa - 1940.
Condition - Excellent.
Size - Currently M 1/2 (UK) or 6 1/4 (US). Complementary sizing is available, can be sized up or down.
Measurements - The opal measures 13.4mm by 9mm and sits 6.3mm from the finger.
Metal - 18k white gold. Stamped.
Maker's Mark - HH
Gatsby Jewellery Ltd has dated this piece to the 1940s.
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