Late Edwardian rectangular open cushion shape cluster ring

Late Edwardian rectangular open cushion shape cluster ring in platinum. Centrally set with an estimated 0.80ct cushion shape Old Mine cut diamond in a millegrain setting, set to the four corners with four round Old European cut diamonds in millegrain settings and bordered by a double row frame of grain set diamonds, to an elegant openwork cluster with intricate settings, pierced openwork and elaborately carved gallery, the fleur de lis shoulders smooth to a slim shank.