An Art Deco ruby and diamond ring, 1920s, of rectangular outline, set with a step-cut ruby measuring

An Art Deco ruby and diamond ring, 1920s, of rectangular outline, set with a step-cut ruby measuring approximately 6.0 x 5.3 x 2.8mm, within concentric borders of single-cut diamonds and calibré-cut rubies, mounted in platinum, size J1/2

Accompanied by report number 79183-77 from GCS dated 25th October 2018 stating that the natural ruby shows no indication of heating, origin: Burma