Inlaid gold pendant

Gold pendant, diam. with loop 3.6cm. Disc of bright yellow gold with beaded wire rim and very fine wire inside again, and corrugated loop soldered at back and rolled over at front. Some damage just below loop at front as if pendant tore and new metal run in, damaging pattern. At centre a cell soldered on, with fine beaded wire collar, and set with piece of black substance flat on top: lignite? (not split) opaque glass? Could just be very dark blue. Rest of surface decorated with filigree double cross pattern. The vertical and horizontal arms plain, made of 4 twisted wires of uneven size - top one only 3 and damaged. Diagonal arms, mainly 2 wires, but occasionally 4, terminate in open loops or forks. Rim worn, loop slightly damaged.