Art Deco Emerald and Diamond ring

A period Art Deco Emerald and diamond ring a stylized rectangle with apex terminals. This ring sits across the finger. The centre diamond is 4mm diameter .25ct approximately surrounded by eight 2mm diamonds all within a border of 3mm calibrated emeralds all within a platinum mount to an 18ct shank. The ring is currently size L/M Not hallmarked but tested 18ct yellow gold.