A mask from the Sanxingdui site in Sichuan province used for sacrificial rituals stands for a bronze civilization dating back over 3,000 years.[Photo by Wang Kaihao/China Daily]

An exhibition running at the Hunan Museum is offering unprecedented access to an array of national treasures gathered from different corners of China, Wang Kaihao reports in Changsha.

A 5,000-year-old jade cong used in rituals of Neolithic Liangzhu culture in today's Zhejiang province may hold the key to unlocking the splendor of the lost and once influential civilization.

Often called the "king of cong" for its size, exquisite decorations and numerous emblems, like other cong, this jade piece forms a tube with a circular inner section and a square outer section.

While some Western scholars may still doubt whether a Chinese civilization from this time could rival cultures that had developed complex metallurgical technologies like Mesopotamia or Egypt, this object not only represents a flourishing state during China's "jade age", but also offers up something of a natural response.

While just 30 cultural relics from over the ages went on display on Saturday at the Roots and Spirits: The Story of Chinese Civilization exhibition at the Hunan Museum in Changsha, marking International Museum Day, the artifacts have such a network of knowledge woven into them that they can be used to retrace how China's early people formed and evolved over millennia.

"From the oceans of civilization, we chose just 30 milestones," Li Jianmao, deputy director of the Hunan Museum, says. "They carry a nation's history, and stand for our people's roots and spirit.