text: Archaeological evidence indicates that the earliest metal objects in China were made in the late fourth millennium BCE. Copper was generally the earliest metal to be used by humanity, and was used in China since at least 3000 BCE.
  Early metal-using communities have been found at the Qijia and Siba sites in Gansu. The metal knives and axes recovered in Qijia apparently point to some interactions with Siberian and Central Asian cultures, in particular with the Seima-Turbino complex, or the Afanasievo culture. Archeological evidence points to plausible early contact between the Qijia culture and Central Asia. Similar sites have been found in Xinjiang in the west and Shandong, Liaoning and Inner Mongolia in the east and north. The Central Plain sites associated with the Erlitou culture also contain early metalworks.
  Copper manufacturing, more complex than jade working, gradually appeared in the Yangshao period (5000–3000 BCE). Jiangzhai is the only place where copper artifacts were found in the Banpo culture. Archaeologists have found remains of copper metallurgy in various cultures from the late fourth to the early third millennia BCE. These include the copper-smelting remains and copper artifacts of the Hongshan culture (4700–2900) and copper slag at the Yuanwozhen site. This indicates that inhabitants of the Yellow River valley had already learned how to make copper artifacts by the later Yangshao period.
  The Qijia culture (c. 2500–1900) of Qinghai, Gansu, and western Shaanxi produced copper and bronze utilitarian items and gold, copper, and bronze ornaments. The earliest metalworks in this region are found at a Majiayao site at Linjia, Dongxiang, Gansu. "Their dates range from 2900 to 1600 BCE. These metal objects represent the Majiayao 馬家窯 type of the Majiayao culture (c. 3100–2700 BCE), Zongri 宗日 Culture (c. 3600–2050 BCE), Machang 馬廠 Type (c. 2300–2000 BCE), Qijia 齊家 Culture (c. 2050–1915 BCE), and Siba 四壩 Culture (c. 2000–1600 BCE)."
  At Dengjiawan, in the Shijiahe site complex in Hubei, some pieces of copper were discovered; they are the earliest copper objects discovered in southern China. The Linjia site (林家遺址, Línjiā yízhǐ) has the earliest evidence for bronze in China, dating to c. 3000 BCE.