Study on Gemmological and Mineralogical Characteristics of She Inkstone

The gemmological and mineralogical characteristics of She inkstone samples from Wuyuan County,Jiangxi Province,are deeply studied by using electronic balance,micro sclerometer,polarizing microscope and X-ray powder diffraction(XRD),environment scanning electron microscope(ESEM) with its X-ray energy-dispersive spectrometer(EDS),including the geological survey,compositions,content and structure characteristics of She inkstone samples.The testing results show that the average Mohs hardness of the samples is up to 4.45 and the average density is up to 2.7485g/cm³,where the major mineral is sericite with small scaly structure and orientational arrangement,and the other minerals are quartz,chlorite and a small quantity of zircon,orthoclase,kaolinite and bornite,etc.Through environment scanning electron microscope and X-ray energy-dispersive spectrometer,the results indicate that the major mineral of the samples is Si-rich sericite,whose monocrystal is of being well,leaf-shaped and orientational arrangement,with its aggregate being imbricate characteristics.The average chemical formula of Si-rich sericite in the sample is K_0.59Na_0.50{(Al_2.86Mg_0.50Fe³⁺_0.75)_4.11[(Al_0.91Si_7.09)₈O₂₀](OH)₄}.