An Art Nouveau pearl, enamel and diamond brooch, circa 1905, designed as a hemlock flower in gold

An Art Nouveau pearl, enamel and diamond brooch, circa 1905, designed as a hemlock flower in gold and pearls, its leaves of green plique à jour enamel, between foliate scrolls set with rose-cut diamonds, mounted in gold and platinum, length 3.9cm, French assay marks for gold, maker's mark HM with jug, MD mark for mixed metals, brooch fitting deficient, pearls untested, fitted case embossed with the initials SD, stamped Maison Robert-Degeresme - J. Lanier-Robert