Early brass from the Foyemiaowan-Xindiantai cemetery, 265–439 ce: the origin and diffusion of brass in ancient China

Abstract

The Foyemiaowan-Xindiantai cemetery, with more than 10,000 tombs, is located in north-west Gansu Province. The cemetery was active during the Sixteen-State Period of the Western Jin Dynasty (265–439 CE). As the largest ancient tomb group in the Dunhuang region, its cultural core is still mainly based on the cultural tradition of the Central Plains. Metal objects were texturally and chemically analyzed by optical microscopy (OM), scanning electron microscopy coupled with energy-dispersive spectrometry (SEM–EDS), and Raman spectroscopy. The analysis of 36 copper-based objects showed that the main alloying elements were tin and lead, while three objects were brass, with copper and zinc as the main elements. These three pieces of brass are the earliest brass objects found in Gansu Province. The brass contains numerous sulfide inclusions, indicating that the raw materials used to make these objects contained a large amount of residual sphalerite instead of being “pure” calamine. They were then hot forged directly from the original smelted brass, without having been remelted. Brass may have reached China during the Wei Jin Southern and Northern Dynasties (220–589 CE), but it was not widely used in China before the Ming Dynasty (1368–1644 CE). According to the statistics and relevant studies of brass unearthed before the Ming Dynasty in China, although the distribution of brass objects spans a considerable period, it concentrates in three areas from the early to the late stage, showing phased development characteristics. This includes accidental smelting in the Central Plains and Haidai areas, followed by external introduction in the northwest, and the emergence of local production in northeast China. Most brass objects contain lead and tin, which requires further exploration.