Cushion Cut London Blue Topaz & Diamond Pendant Necklace in solid 9ct white gold. Size: 9.5 x 19.1 mm (0.37 x 0.75 in). Material: White Gold. Total metal weight: 1.0 gr. Cushion cut London blue topaz (10 x 8 mm) = 3.25 ct total. Round brilliant cut diamond (1 x 1 mm, I colour, I1 clarity) = 0.025 ct total. Colour: Blue. Stone cut: Cushion Cut. Anniversary: 4th Anniversary. Birthstone: November.