Art Deco black opal necklace. A mesmerizing and gemmy Lightening Ridge black opal is elegantly and artfully presented in a consummate Art Deco pendant necklace, finely handcrafted at the peak of Art Deco period - circa 1925. The fabulous pear-shape opal displays an electric and iridescent kaleidoscope of predominantly blue, green and orange hues with a splash of red. The platinum and diamond setting is signed Walton & Co.- a high-end retailer of the period. Lang Antiques.