French 19th Century 18ct Gold Signet Ring With Hinged Locket Inside

An unusual late 19th century 18ct75% pure gold (or 750 parts pure gold and 250 parts other metals) gold ring that was made in France. It has been set with a plain carnelian​A translucent red variety of chalcedony which in its turn is a form of cryptocrystalline quartz. ​Carnelian has​ been known and used since antiquity when it was sourced from the surfaces of the Egyptian and Arabian deserts. The ​most prized carnelian has a true blood-red color.. There is a hinge on one side and it opens to reveal a secret locket compartment.