Crispin Jewellery has dated this piece to the Edwardian era.
This piece is most likely made in France
HALLMARKS
Not Hallmarked so tests as

MEASUREMENTS
Three large Old transitional cut diamonds measures;
5mm- 0.65ct clarity VS 2 colour J
4.5mm- 0.40ct clarity Si3 colour J
2 x 3.5mm clarity Si1-P colour H
Smaller rose cut diamonds 1.5- 2mm
Total carat weight 1.60ct measured in situ but these are deep stones

Ring head; 18 x 19mm including the diamond shoulders. This is a really fine quality piece
This is a particularly amazing piece, superb design and beautifully white diamonds
WEIGHT
4.5g
CONDITION
Good condition, wear commensurate of age. A beautiful and sought after traditional design. Not a reproduction.
RING SIZE
GB O 1/2
Crispin Jewellery has dated this piece to the Edwardian era.
You can view the stock and full dealer information on the Crispin Jewellery Profile Page