An important Edwardian platinum diamond cluster plaque brooch by Percy Marks the 62 x 28 mm pierced and mill grain set openwork, symmetrically designed; brooch has a 2.22ct J-K / SI1 clarity old cut diamond bezel set; at its centre with a 1.5ct J-K / VS2 clarity old cut diamond bezel set; on each side and a further 86 various sized diamonds weighing 4.