The physical characteristics of the ancient jades in Lingjiatan site, such as color, transparency, hardness and water-absorption capability etc. had changed much after their being entombed for a long time. Some of ancient jades even show a special phenomenon, which is denser outside, looser inside . Through working on microstructure and micro-analysis of the ancient jade, the conclusion was obtained that after being entombed, the ancient jade in Lingjiatan site went through two stages. One is the weathering and eluviating stage, another is the penetrating and cementing stage. -- ICCROM