Art is always more fascinating when a story attaches to it, whether it is a work of contemporary art or an artifact discovered in an ancient tomb.To the archeologist any new find is amazing. From an ancient tomb going back over two thousand years, a delicate liuli jade has been unearthed.It was found in central China's Hunan province. Liuli jade was used as an ceremonial artifact when ancient emperors made sacrifices to the Heavens.Though it was broken in two pieces, the artifact astonished beholders with its superb craftsmanship. The jade was discovered in a well-preserved tomb dating from the warring states, 2,200 years ago.Experts say the tomb belonged to civilians. The jade piece was placed against the back of the head to drive away evil. According to Sotheby's, there are only four well-preserved liuli jade pieces known in the world.