Jade Plaque with Animal Mask Desgin, Hongshan Culture (c. 4700-2900 BC), unearthed at Niuheliang, Lingyuan, Liaoning Province, 2003. It is exhibited in the section of Life and Production in Neolithic China, an exhibition of Ancient China in the National Museum of China. The Neolithic Age began about 10,000 years ago. This period featured the advent of agriculture, domesticated animals, polished stone tools, and the invention of pottery. People began living in settlements with blood relatives and the economy was gradually transformed into a production-based one. [Photo by Xu Lin / China.org.cn]