The Study On Mineralogical Characteristics Of Serpentine Jade From Kuancheng,Chengde

Serpentine jade in Kuancheng,Chengde is mainly produced in the eastern edge of Kuancheng Manchu autonomous county in Chengde and the border of Lingyuan city,Liaoning province,it is calls"rehe jade",its color is rich,the quality of a material is exquisite,have certain market value.At present,there are few research materials on serpentine jade in Kuancheng,Chengde.The research on serpentine jade in Kuancheng,Chengde is mainly about gemology and mineralogy,so as to improve people's scientific understanding of serpentine jade in Kuancheng,Chengde.Combining with the results of previous studies,the gemology characteristics,mineral composition,structural features,chemical composition characteristics,color mechanism and radioactive features of serpentine jade from Kuancheng,Chengde have been studied in this thesis,with the experiments including regular gemology tests,microscopic observation,infrared spectrum,Laser Raman Spectroscopy,XRD,UV-Vis-Infrared Spectrum and LA-ICP-Ms etc.And discusses the quality of serpentine jade in Kuancheng,Chengde.Serpentine jade of Kuancheng,Chengde is rich in color,mainly light pink and green,light pink color is not uniform,can appear two or three colors.The color of the green samples is uniform,and the samples can appear gray-green and blue-green.It has weak glassy luster.The relative density of the pink sample is 2.31-2.54,and the refractive index is1.53-1.55,the relative density of the green sample is 2.57-2.62,and the refractive index is1.55-1.56.Mohs hardness:3-4.The main component mineral of serpentine jade in Kuancheng,Chengde is serpentine under the Polarizing microscope.The secondary minerals of the samples are calcite,dolomite,diopsidetremolite,talc and pyrite.The texture of serpentine jade can be devided into fiber interweave structure,microscale lepidoblastic texture,micro flake variable crystal texture,nematoblastic texture and brecciation.The main structures are massive structure,taxitic structure and banded structure.The results of infrared spectrum,laser Raman spectrum and X-ray powder diffraction showed that the main mineral composition of the pink samples was clinochrysotile,and it also contained a small amount of orthochrysotile,lizardite,calcite,dolomite and diopside.The main constituent minerals of the green samples are antigorite,and a small amount of clinochrysotile,tremolite,talc and pyrrhotite.Through the electron probe test and analysis,the main element content of the pink samples and green samples were not significantly different,and the content of Fe O,Al₂O₃and Na₂O in the green samples were significantly higher than that in the pink samples.In the part of local breccia in pink samples,the chemical composition of serpentine is shown in both breccia area and cementitious area,and the content of major elements is not significantly different.Feo content of serpentine in cementitious area is lower than that in breccia area.Feo content of serpentine in breccia area is lower than that in breccia area.The chemical composition of serpentine in light pink,deep pink and yellow-green areas was similar,and the iron content of serpentine in yellow-green area is higher than that in light pink and dark pink area.According to the test of uv-visible spectrum and LA-ICP-MS,it is speculated that pink is caused by the combination of Fe³⁺and Mn²⁺,yellow green is caused by the combination of Fe³⁺and Mn²⁺,and green is caused by the combination of Fe²⁺and Fe³⁺.