A Comparative Study Of Amber In Fushun China, Mexico And Myanmar

Amber is a very complex resin fossil formed by natural vegetable resins through polymerization and evaporation in the long geological process.It is a very important organic gemstone which has a very beautiful appearance.It can be traced back to the Mesozoic Cretaceous and Cenozoic Miocene at the latest.At the same time,amber is widely distributed all over the world,including China,Myanmar,Dominica,Mexico and many countries along the Baltic Sea,across the Eurasian continent and even the American continent.Among these origins,the formation ages of amber from Fushun,Mexico and Myanmar in China are quite different.Therefore,amber samples from these three different origins are selected.By comparing their origin,formation age,Gemological characteristics,spectral characteristics and chemical composition,I got some similarities and differences between them,and studied in depth the methods and differences between different origins of amber species and chemical composition.The main research results are as follows.The basic gemological characteristics of amber from Fushun,Mexico and Myanmar are similar with some differences.The general color of amber in Fushun is darker and more transparent.Coal gangue is common on the surface of raw stone.Blue-green fluorescence and low hardness are common in Mexican amber under black background.The hardness of amber in Myanmar is the highest and abnormal fluorescence color often appears under ultraviolet long wave.By means of infrared spectroscopy,Raman spectroscopy and ultraviolet-visible spectroscopy,it was found that the formation age of amber from three major producing areas was consistent with the previous conclusions,which satisfied that Myanmar was earlier than Fushun and Fushun was earlier than Mexico.The R value calculated by infrared spectroscopy(R=A_1381cm^-1/A_1456cm^-1)and the N value calculated by Raman spectroscopy(N=I_1645cm^-1/I_1450cm^-1)both meet the formation age earlier and the value smaller.Therefore,R value and N value can be used to help distinguish the origin of amber.The characteristics of Burmese amber can be identified by the absence of the absorption peak of 1645 cm^-1 in infrared spectrum,the Raman shift of 1645 cm^-1 and the absorption of 321 nm in ultraviolet-visible spectrum.The stretching vibration of ester C=O in red samples is stronger than that in yellow samples in the infrared spectra of amber samples from three major producing areas.It shows that besides oxidation degree,esterification degree of red samples should be generally higher than that of yellow samples,which is independent of producing areas.Using GC-MS to study the samples of amber from three major producing areas,assistant spectral data,it is judged that Fushun amber is ClassIb type amber,resin source is coniferous resin;Mexican amber is ClassIV type amber,resin source is leguminous resin in angiosperms;Myanmar amber is ClassIb type amber,resin source may be extinct Taxodiaceae resin.Vario-ELcube organic element analyzer was used to analyze amber samples.The results showed that the C/H ratio met the requirements of Myanmar>Fushun>Mexico,wi to study the samples of amber from three major producing areas a high degree of discrimination and non-coincidence between origins,which could be used as one of the diagnostic criteria for judging the origin of amber.