The Alteration Characteristics And Mechanism Of The LiangZhu Culture Jade Artifacts Excavated From Zhuangqiaofen Site

Throughout the ancient world, China was the only country with prosperous and continuous jade culture lasting 8000 years. So jade culture was often regarded as the initial watershed between the eastern and western civilization, and also one of the most important Chinese traditional culture symbols. For the special culture of Chinese jade, it was widely collection as the cultural wealth from home and abroad. Natural colored antique tremolite nephrite jades are much more valuable than artifical colored ones, so it is significant for identification of antique tremolite nephrite jade to distinguish whether its color is natural or artificial. It is helpful for the technology improvement of antique tremolite nephrite jade identification to study the genesis of its natural color and artificial color. However, such studies are few.In this paper, through macroscopic examination and magnification observing the alteration characteristics of the 361 pieces of jade artifacts excavated from Zhuangqiaofen site, and do the reflection and transmission of infrared absorption spectrum (IR), Raman spectroscopy (Raman), Electron probe micro-analysis (EPMA), scanning electron microscopy (SEM) and laser erosion inductively coupled plasma mass spectrometry (ICP-MS) test to a few samples, and analysis ancient jade in terms of identification, the material origin and the secondary change, we've got some conclusions:1) After the test of FTIR, Raman and EPMA, we concluded the six more fresh samples was tremolite and the four white chicken bone samples was the serpentine. After weathering, the transparency, gloss and hardness are lower, but the jade materials have no changed.2) Through geological occurrence type of method, six tremolite samples were originated from the magnesia in the marble.3) REE content distribution is applied to staying the tremolite-origin. The result indicates that the REE distribution patterns and characteristic ratios of the samples are the same, show that they have similar occurrence. Cluster analysis method is applied to staying the tremolite-origin. The result indicates that sample M11 was further away from the A07, A08, F06, the distance reflects the close relations between the mine. And the test results matched their optical characteristics and mechanical characteristics.4) The ICP-MS data of the more serious erosion samples was separated by two parts, for their skin and internal have different chemical composition, and this is also reflected on the content of REE. After the erosion, the content of REE has increased on surface, and it enriched of light REE. Maybe the absorption capacity of the surface of sample have enhanced after erosion, so it can adsorption the light REE in clay sediments.5) The most of jade which artifacts excavated from Zhuangqiaofen site were erosion from mild to thorough. The look of erosion part of jade have eroded hole (Mayi Dong), Hang erosion, erosion spots, erosion ditch, erosion vein (mesh and whirlpool) and surface erosion, and so on. The different jades have different alteration characteristics, the weathering morphology of agate shows spots, the fluorite is layered, and the green quartzite is netlike.6) Using a large number of different degrees of the jade artifacts, we can concluded the development process of how ancient jade turns into chicken bone-like color. The determining factor of the weathering shape was the lines of polishing at first, while the crystal granules at last. The burial environment is the primary factor of erosion. The different erosion degree and shape was seen on one jade, and this proves that the reasons of chicken bone-like color can not be conducted just to deal with.7) The main elements of jade was lost while erosion, the erosion degree and other elements of external is higher than internal, Trace elements in the process of erosion also have some changes: Na and K elements only higher on the surface, not to internal erosion, show that these two elements was only absorption into the ancient jade. Observation from SEM, we've found the tubular clay minerals and irregular Flake kaolinite in the internal of jade, it proved that the elements of Al have erosion to internal part of jade.8 ) Through our Observation, proofed that the jade had gone through the weathering-eluviating stage and penertrating-cementing stage.C11 sample with the special yellow structure is the infiltration of the penertrating-cementing stage.