1970's 18ct White Gold Sapphire & Diamond Cluster Ring

Vintage 1970's circular cluster.  Three slight tiers, centre being a single brilliant cut diamond with a surround of six brilliant cut diamonds and terminating in a surround of twelve round mixed cut dark blue sapphires.  The total diamond content is estimated as 0.70ct.  Colour estimated as I/J.  Clarity estimated as SI2.  Overall the cluster measures 16.65mm in diameter and sits 12.5mm high.  Mounted in all 18ct white gold with claw settings, finger size N.  Fully hallmarked London 1979.  Gross weight 6.3g.