This is a modern 18ct cluster ring, A cluster ring is a ring that features a primary diamond in the centre and is surrounded by a circular halo of smaller diamonds, in this case a round faceted aquamarine set into a raised rub over setting with eight diamonds surrounding with two on each shoulder.
Metal: 18ct gold.
Marks: DDM, 750, Birmingham.
Stones: One round faceted Aquamarine of mid blue colour, set into a raised rubover setting. Surrounded by eight brilliant-cut diamonds each weighing approximately 0.075ct. with four approximately 0.01ct diamonds two on each shoulder. Total weight combined is 0.64ct. Clarity is VS1, Colour is G/H.
Measurements: The face of the ring is 12.5mm in diameter, 7mm proud of the finger, 2mm at the back of the finger.
