Platinum opal and diamond brooch, circa 1930; of Art Deco design centring a claw-set oval-shaped cabochon opal weighing approximately 18.62 carats, within an openwork geometric frame accented with millegrain-set old mine-cut diamonds together weighing approximately 1.16 carats, mounted in platinum with a 14ct gold brooch pin, length 37 mm, width 31 mm, total gross weight approximately 13 grams.; accompanied by a box.