Centering a prong set, Rectangular Cushion cut sapphire (no evidence of heat treatment), measuring approx 6.25 x 4.90 x 4.0mm; with an approx. weight of 1.08ct. Open gallery with minor black champleve enamel* detailing; along with pierced open shoulders with a foliate and scroll motif. Fashioned in 18k yellow gold. Stamped "18". Hallmark for London Assay Office. 1876. Size 7. Although vitreous enamel forms a hard, durable surface, it is susceptible to chipping and breaking upon impact.