Corvidae Antique has dated this piece to the Victorian era.
Note the lovely detailing on the shoulders.

SIZE: L and a half (UK), 6 (US). The gem-set face of the ring is approx 2cm when measured straight across and 9mm tall.
WEIGHT: 1.9g.
MATERIALS: Nine-carat (375) gold, amethyst, pearl.
HALLMARKS/STAMPS: Hallmarked for nine-carat gold, Birmingham Assay Office, and stamped NBS.

CONDITION: In good antique condition, with some wear to the claws and the facets of the amethysts; all the stones are firmly set and the pearls have retained a lovely nacre. The ring has been resized at some time, losing the date letter of the hallmark.
ERA: Estimated Victorian c.1860s.
Corvidae Antique has dated this piece to the Victorian era.
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