For decades Liangzhu culture in eastern China dating back to some 5,000 years ago has been the focus of numerous archaeological studies because of its vital role in the creation of Chinese civilization. But some mysteries remain unsolved.

It is not known how stone and jade objects such as ceremonial cong, yue, and bi, strings of tubes, hair ornaments and bracelets are so smoothly polished, delicately carved out, or drilled with holes by primitive Chinese craftsmen.

Some researchers believe they may have learned to use diamonds to grind and polish these items while others believe the craftsmen used metal tools or techniques still unknown today to fashion their masterpieces.

Another mystery is the source of the raw materials used to make stone yue axes of different colors and sizes, displayed at the grand exhibition "Dawn of Civilization" at the National Museum of China.

For decades, archaeologists have been unable to figure out where the primitive people got the volcanic lava to make the axes. No volcanoes have been found in the areas where the Liangzhu culture was located, or even in neighboring regions.

Most jade bi, wide discs with a perforated hole in the centre, have lost their original greenish color and appear white. Archaeologists are divided on the matter of their function. Some believe the jade bi discs are for sacrificial purposes while others hold the discs are used as a symbol of great fortune.

Most jade bi discs of the Liangzhu culture bear no motifs, but on the surfaces of some strange signs have been minutely carved.

Similar motifs have been found on the surfaces of such jade objects as yue axes and cong. But their meanings are still unknown to researchers today, according to Liu Bin, a researcher at the Zhejiang Institute of Archaeology and Cultural Relics.

One thing all researchers agree on is that the motifs are related to primitive god-worshipping practices.

But at the same time researchers are struggling for answers to questions such as: where did the primitive tribes of the Liangzhu culture go?

Some archaeologists believe the Liangzhu tribes moved north and south, integrating with other tribes, while other researchers believe Liangzhu culture tribes were destroyed by excessive floods or submerged by seawater.

Stone sickles that have been excavated indicate most people from the Liangzhu culture were left-handed farmers.

"About 90 per cent of the stone sickles found were obviously used with the left hand," Liu Bin said. "Meanwhile, most primitive tribes of the same period found in central China are mostly right-handed. We cannot say why there is such a big difference."

"There are so many mysteries that need to be unraveled about the Liangzhu culture," Liu added.

Archaeologists still do not know whether the beautifully carved three-pronged jade plaques, on show at the exhibition, are used as ornaments or for sacrifices.

(China Daily September 1, 2005)