A French Art Deco natural saltwater pearl and diamond plaque brooch, c.1925, with a 9.1mm taupe coloured natural pearl, peg set to the centre. An oval frame of eight cut diamonds with pairs of arches, all grain set with diamonds. A rectangular plaque with stepped corners, grain set with graduated Swiss cut and eight cut diamonds to a plain pin and 'C' catch. Tested as platinum, French poinçon. 40 x 24mm, 9.48g Accompanied by a report from Gemmological Certification Services dated 04/06/2021, no. 81310-57, stating: Natural saltwater pearl, no indications of treatment Condition report: Pearl not perfectly spherical. Slightly darker in colour towards the base. Some ripples.