Archaeological gilded metals excavated in Japan

It is no exaggeration to say that in ancient Japan many metal working techniques were brought from the Asian continent; gilding was no exception. A review of ancient excaated objects from Japan shows that most of the metal objects with gold surfaces were gilded, that is, a layer of gold was applied over a base metal, giving the appearance of a solid gold object. Indeed, in Japan ancient metal artifacts in pure gold were fire-gilded, a technique, also called mercury amalgam gilding, by which a pasty amalgam (mixture) of mercury and gold is applied to a clean base metal surface, then heated to drie off the mercury (Oddy 1981, 1993). To study and characterize this gilding technique on ancient Japanese objects, newly fire-gilded samples were prepared. Using a scanning electron microscope (SEM), a comparison was made between the excavated artifacts and control samples replicated with traditional methods. The micromorphological features of fire-gilded surfaces were clearly revealed. Other analytical tools such as X-ray fluorescence analysis (XRF) and X-ray diffraction (XRD) were also used. Among the metal artifacts excavated in Japan some examples with foil or leaf-gilding, techniques whereby arying thicknesses of gold sheet are attached to the surfaces of base metals, hae been found. Artifacts gilded using these technique were also examined with SEM.