The Study On Gemological And Mineralogical Characteristic Of Shilin Colorful Jade From Yunnan Province

Shilin Colorful Jade was found in Shilin Yi autonomous county,Kunming city,Yunnan province.In this paper,taking Shilin Colorful Jade as the research object,the conventional gemological properties,microstructure characteristics,mineral composition and chemical composition of shilin colored jade were systematically studied by means of polarizing microscope observation,scanning electron microscope and energy spectr?m analysis,Fourier infrared spectrometer,microscopic Raman spectrometer,X-ray powder diffractometer,electron probe,X-ray fluorescence spectr?m analysis,differential thermal analysis and ultraviolet visible spectrophotometer,and its color origin was also discussed.For the convenience of writing this article,the following will be written as Shilin Colorful Jade.Shilin Colorful Jade is a kind of cryptocrystalline quartzose jade,which is produced in placer in the form of blocky and banded spots.The color is mainly red and yellow,and there is no cleavage in other colors such as orange,brown,green,black,white,gray,violet and blue.No cleavage,most of the polishing can be glass luster,a small n?mber of waxy luster,transparent to opaque.The refractive index of Shilin Colorful Jade were between 1.52?1.56,the relative density were between2.56?2.83,and modeni hardness were between 6.3?7.0.Under ultraviolet fluorescence,it was mostly inert.The research shows that the structure types of Shilin colorful Jade under orthogonal polarized light are mainly fibrous and fine-grained.The fibrous structure also includes about 1mm long fiber,200?m?500?m short fiber and radial fan structure.The particle size of granular quartz is about 0.1mm?1mm.The surface of the sample can be seen with large area of b?mp or depression under sem.The cathodol?minescence of Shilin colorful Jade is weak,most of them do not emit light,and the areas stained by iron in some red samples emit bright orange light.Shilin colorful Jade the main mineral composition of the alpha quartz,containing a small amount of other minerals such as calcite,oblique,silica,mica,hematite,68°five fingers diffraction peak measurement method is used to calculate the stone forest in the color of jade quartz crystallinity index,average,about 4.17,shows the crystallinity index on the low side of the sample.The chemical composition of Shilin colorful Jade is SiO₂,and contains Fe,Mn,Ca,Cl,Al,K,Zr,V,Sr,Ti,Cr,Na,S and other elements.The red and green samples contained a small amount of adsorbed water,about 1.35%,and the red and yellow samples contained a small amount of crystal water and structural water,about 1.04%?3.00%.The first derivative spectr?m of ultraviolet spectrophotometer shows that the yellow color of Shilin colorful Jade is caused by goethite and the red color is caused by hematite.