A chalcedony and enamel ring, converted from a mid 19th century clasp, set with a cushion-shaped green chalcedony within a bead and wirework surround with red and white enamel flowerheads, to a reeded hoop, hoop with French import marks, ring size M-N. £500-£700

According to a PMI test on an XRF Analyzer, the ring is testing as 18ct gold.