gold with traces of black enamel has seven mirror-backed facetted glass pastes. these 'vauxhall pastes' were flat-backed glass paste gems whose facetted surface was reflected in the mirrored back giving an illusion of depth.
Brooch Boucheron circa 1900 Plique-a-jour enamel, gold, rubies, opal, and aquamarine. I restored this (above) antique brooch for her. She trusted me. Image from Elizabeth Taylor My Love Affair With Jewelry (photographer's note)
Brooch centering upon a purple and blue plique-à-jour enamel landscape, within a scrolling sculpted gold surround, reverse-set marquise-cut sapphire and calibré-cut sapphire detail, mounted in gold, circa 1905
ring size 7 over here! :D BELLE EPOQUE AMETHYST AND DIAMOND RING Set with an hexagonal amethyst to the openwork millegrain diamond-set gallery and half-hoop, circa ring size with French assay marks for platinum and gold Christie’s.