Gemological Characteristics Of Xue Cha Amber From Burma And Analysis Of Related Color Change Experiments

Xue cha amber from Burma is a new type of amber.It is named for its orange-red-red color and bright appearance.In this paper,the xue cha amber of Myanmar is studied,and it is systematically studied by conventional gemological test method,energy dispersive X-ray spectrometer,infrared spectrum,ultraviolet-visible spectrophotometer and Raman spectroscopy.A heat treatment,irradiation and other color-changing experiments were carried out on Jinpo,Myanmar to explore whether the appearance of xue cha amber can be obtained by heat treatment or irradiation,and provide an experimental basis for the heat treatment and irradiation treatment of Myanmar amber..There are many discoid fissures,dark opaque inclusions and reddish brown hulls in the xue cha amber in Myanmar.The refractive index is 1.54 and the relative density is 1.0584.It exhibits strong blue fluorescence under long-wave UV lamp and undulating abnormal extinction under orthogonal polarized light with rich interference color.The EDXRF test results show that the content of S element in Myanmar xue cha amber is higher,and the higher the content of S element,the darker the color.The FTIR test results show that the basic molecular skeleton of Myanmar xue cha amber is an aliphatic structure and contains oxygen-containing structures such as alcohols,esters and ethers.The ultraviolet spectrum of Myanmar xue cha amber shows the n→π*transition absorption peak at 250 nm.The results of Raman spectroscopy show that there are strong vibration peaks at 2800-3000cm^-11 caused by CH stretching vibration and 1400-1500cm-1 caused by CH bending vibration in Myanmar.These Raman vibration peaks are mainly composed of carbon chain skeleton.Caused by vibration.The intensity ratio ofν（C=C）andδ（CH₂）is determined as N=(I1600-1700cm^-1/I1450cm^-1)to characterize amber maturity,and N _{Myanmar xue cha}yanmar xue cha amber<N Myanmar gold amber<N Myanmar heat red amber,that is,the maturity ranking is Myanmar xue cha amber>Myanmar gold amber>Myanmar heat red amber.The color-changing experiments were carried out on Myanmar gold amber by heat treatment and irradiation.It was found that the treated samples all had obvious brown tone and slightly decreased transparency,which could not show the vivid and translucent appearance of xue cha amber.By comparing the properties of the samples before and after the experiment,the refractive index is greater than 1.54,and there is no fluorescence or weak yellow-green and khaki fluorescence under long-wave ultraviolet light.If the infrared spectrum is I=2930cm^-1/I=1735cm^-1≤1,the ultraviolet spectrum,Raman spectroscopy becomes smooth and other features can be used as an important basis for the identification of Myanmar amber heat treatment;irradiation treatment is difficult to identify,the smooth wide absorption band in the near-ultraviolet region,and the Raman characteristic peak are obviously weakened or disappeared,which can be used as an identification of Myanmar amber spokes.The auxiliary basis for the treatment.