platinum and diamond ring

A fine platinum engagement ring featuring a brilliant cut diamond (app. 0.3 carats, circa G color; VS1 clarity), on each side flanked by a cartouche with three single cut diamonds (app. total 0.45 carats), signed and numbered: J.E. Caldwell & Co., N7265, U.S.A., circa 1920.

weight: 3.3 grams
size: 17 mm.