Mineralogical Research And Quality Evaluation Of Hetian Jade

Nephrite is loved by the people,the Hetian jade produced in the Hetian area of Xinjiang is well-known in the world because of its rounded texture.But with the increasing scarcity of nephrite resource.There are many problems such as origin identification,quality evaluation and skin co1 or identification.establish a recognition model,and then the samples were recognized.The experimental results of the three origins were all Hetian jade.By using terahertz-time-domain spectroscopy technology,the absorption coefficient,refractive index,and relative permittivity of Hetianyu in the 0.2-2.6 THz band of the three regions were compared.In comparison,the change trend of Korean Hetian jade is the slowest,while Xinjiang Hetian jade has a more obvious characteristic absorption peak around 0.65 THz.In the corresponding refractive index spectrum,Xinjiang Hetian jade has a higher refractive,Laser induced breakdown spectroscopy(LIBS),Terahertz-Time Domain Spectroscopy(THz-TDS).(1)Through the structural characterization of Hetian jade in different regions,the results show that the difference in structure is the main influencing factor for identifying the origin and quality of Hetian jade.The mineral crystals in Qinghai material are arranged in parallel in the form of fibers,and the texture is the most delicate and transparent.Korean materials have the smallest mineral particles,arranged in a short columnar shape and non-directionally,and their texture is the most rough and loose.(2)Through studying the mineral composition of Hetian jade in different regions,the results show that the absorption peak at 3654 cm-1 in Hetian jade in Qinghai is due to the substitution of part of Mg by Fe.X-ray diffraction results show that Qinghai materials have the highest crystallinity and the largest crystal grains,while Korean materials have the lowest crystallinity and the smallest crystal grains.(3)The chemical composition of Hetian jade from different regions was studied by testing methods.X-ray fluorescence spectroscopy test data shows that the content of Si O2,Mg O,and Ca O in samples from different origins is relatively stable.It is consistent with the theoretical value of the standard mineral of tremolite,indicating that the main mineral component of the sample is tremolite.ICP-MS results show that,except for the differences in the content of Ba,Se,and V elements,the content of the other three producing areas is not very different from the content of Xinjiang Hetian jade.By comparison,it is found that the content of rare earth elements in Hetian jade from different origins is generally low,and the distribution patterns of rare earth elements are generally similar.And through the principal component analysis and discriminant analysis of the multi-element content in the sampled Hetian jade,the traceability indicators were obtained and verified.The results of LIBS showed that the laser-induced breakdown spectroscopy was used to establish a recognition model,and then the samples were recognized.The experimental results of the three origins were all Hetian jade.By using terahertz-time-domain spectroscopy technology,the absorption coefficient,refractive index,and relative permittivity of Hetianyu in the0.2-2.6 THz band of the three regions were compared.In comparison,the change trend of Korean Hetian jade is the slowest,while Xinjiang Hetian jade has a more obvious characteristic absorption peak around 0.65 THz.In the corresponding refractive index spectrum,Xinjiang Hetian jade has a higher refractive index than Korean materials and Qinghai materials.From the dielectric spectrum,it can be seen that the real part of the dielectric constant of Xinjiang materials is significantly greater than that of Korean materials and Qinghai materials.The morphology of the main components of the sample,the degree of crystallinity of the jade and the size of the particle size are related.