Edwardian diamond brooch

An oval, open-work brooch; old cut diamonds (app. 1.8 carat) set in platinum with an 18 carat gold pin. Signed and numbered: J.E.C.& Co. for Caldwell & Co., G7462. U.S.A., circa 1915.

weight: 6.3 gram
dimensions: 4 x 2 cm.