Ref. CA9131
18th-century blue enamel and rose diamond plaque ring decorated with a rose diamond set urn topped with a rose diamond set fleur de lys and bordered with small rose diamonds, circa 1780-1800.
Although no French marks, just a makers mark "GR" I think this ring is French, the flower engraving on the reverse and the triple flower decorated shank seems to point to a French origin.
The head of the ring measures 2.8cm x 1.6cm
Finger size is M 1/2 or N