A scientific study of Eastern Zhou bronze weapons with tin-rich surface decoration

Abstract

• In this paper we examined three bronze weapons with tin-rich surface decoration from the Eastern Zhou period: a sword (1966,0222.1) with a trellis pattern, a spearhead (1947,0712.426) with a hexagonal star pattern in the British Museum collections, and a sword (GT698) with a trellis pattern from a private collection. These weapons may have come from south eastern China, a region renowned for its weaponry production in the Eastern Zhou period, as both their styles and decorations are comparable to the sword of the Yue King Goujian and the spearhead of Wu King Fuchai, two of the most typical objects of this type. The manufacturing and surface tin-rich decoration techniques were investigated using microscopy, X-ray CT imaging, X-ray fluorescence spectrometry, scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, and X-ray diffraction. The results showed that all the objects were made of high tin bronzes. The swords were made by casting a grip around the pre-cast blade and the pommel. The spearhead was an integral casting. The trellis pattern on the swords was probably produced by heating up a tin-rich paste applied to the surface and the thin hexagonal star decoration pattern on the spearhead was probably produced by brush painting with a mercury-tin amalgam followed by heating.