18K (750/oo) white gold and platinum (850/oo) brooch with openwork geometric design, entirely set with old-cut and half-cut diamonds, the central ones measuring approximately 2 x 1.15 ct. A small diamond is missing and there are a few chips and scratches. Dimensions: approx. 57 x 27 mm. Total diamond weight: approx. 7.50 ct. Some weaknesses on the band. Gross weight: 18.6 g.