Microstructure of Jadeite Jade Synthesized under High Pressure

In this work we prepared sample primary material for synthesis of jadeite jade adopting the sol-gel method, reduced the bubbles in it by melting it many times at high temperature and, after it, obtained bulk transparent glass materials containing the jade chemical component (NaAlSi₂O₆). In order to promote its plastic deformation, reduce its residual stress and prevent its cracking, we treated the sample by compression and decompression at high temperatures and under high pressures. The jadeite sample so synthesized maintains good forms as blocks, and its phase composition and microstructure are all highly close to those of natural jadeite judging by the analysis of X-ray diffraction (XRD) and scanning electron microscope (SEM). It is found that the major influence on the quality of sample jade synthesized under high pressure is the microstructure of the jadeite jade crystallized from the primary glass material, i.e. the volume, morphology, alignment, compactness, etc. of the crystalline grain.