Electroformed Gold Bracelet
GIA has provided a service for validating mounted gemstones in jewelry for decades. Recently, these services have been expanded to include precious metal items (rings, necklaces, and bracelets) to ensure their authenticity and ensure the metal is as stated. The service is intended to protect both buyer and seller.
As part of this service, a gold bracelet measuring 8 inches in circumference and 1.25 inches wide and weighing 41 g was recently examined in the Carlsbad laboratory (figure 1). It was submitted as 14K solid gold, but initial observations raised suspicion. The bracelet felt too light and almost hollow, and there was a significant contrast in textures: a matte finish on the inside surface of the bracelet compared with the wavy, shiny exterior surface. The bracelet had a 14K hallmark, which appeared to be stamped or engraved onto a different metal piece that was glued or otherwise adhered to the bracelet (figure 2).
X-ray fluorescence (XRF) analysis of the shiny exterior surface gave a result of 17.99K gold, and no subsurface material was detected that would indicate plating. Additional testing of another smooth surface yielded a result of 22.47K. Further analysis under brighter lighting conditions revealed areas where gold plating had flaked off from the piece (figure 3). We believe this wavy texture of the gold was used intentionally to hide the poor quality of the finish and the flaking gold plating, as shadows can often mask imperfections on initial sight.
A wax or resin material was observed under the plating, and we concluded that the bracelet had been created using electrodeposition to electroform the piece. Electroforming is a method of adding a thick gold plating, sometimes as thick as 200 microns, to a wax, resin, ceramic, or organic material base. Thick plating and electroforming may not be detected by XRF methods alone, and additional testing may be necessary to detect the application of these processes. We believe this wax- or resin-filled electroformed bracelet was being sold as solid 14K gold with the intention to deceive the buyer. This example demonstrates the importance of testing and verification services such as GIA’s jewelry verification service.
