Lajia Ruins in NW China's Qinghai a proof of prehistoric civilization (3)

Photo taken on Oct. 17 shows a piece of raw jade at the Lajia Ruins Museum, Minhe County, northwest China's Qinghai. Lajia Ruins, dubbed "Pompeii of China," was formed by an earthquake and flood dating back 4,000 years. The Lajia site is the largest disaster excavation site found in China so far. (Photo: China News Service/ Ma Mingyan)