ART NOUVEAU PLIQUE-À-JOUR ENAMEL AND DIAMOND LEAF BROOCH, FRENCH, CIRCA 1900. Designed as a maple leaf of shaded green and gold plique-à-jour enamel, accented throughout with rose-cut diamonds, mounted in gold and platinum, indistinct maker’s mark possibly HB, French assay mark, brooch fitting detachable, pendant loops at the top.