The Gemological Characteristics Of Natural Ambers And Imitations

Amber is a resin fossil from the Mesozoic Cretaceous to the Cenozoic Tertiary pine and cypress or leguminous plants secreted by the resin,which has been buried underground and subjected to long-term geological action.In recent years,Amber has been welcomed by consumers,a large number of imitations in the market,to consumers and the identification of workers brought a lot of confusion.Based on previous research,using the ambers from Baltic Sea,Burma,Fushun and their imitations as the research objects,the paper has been done some research on gemological characteristic and chemical composition mainly through using modern testing methods such as microscope observation,laser Raman spectrum and Infrared Spectroscopy.Combined with the characteristics of the three kinds of amber,to explore the origin of the different characteristics of the impact of amber,so as to further understand the characteristics of amber;Through the comparative study on the characteristics of natural amber and imitation,it provides the basis for identification of natural amber and its imitations.Observation and testing showed that the natural amber yellow,Burma amber more brown,Fushun amber mostly red or orange,Baltic Sea Amber with bright yellow;Amber material for resin luster,polished resin luster to near-glass luster;Transparency renders transition state;the refractive index is about 1.54,the relative density 1.073g/cm3,hardness 2~2.5,Burma amber hardness slightly higher than 3;Burma Amber is a strong blue-white fluorescent,Fushun amber is a light blue white,bluish purple fluorescence,the Baltic Sea amber fluorescence reaction is weak;under the microscope observation,Burma amber interior black Impurities More,the Baltic Sea Amber interior bubble More,Fushun amber visible inside a large number of black impurities,appear flow pattern distribution.Burma Amber,Fushun Amber,Baltic Sea Amber Infrared Spectroscopy and Raman Spectral Peak are roughly the same,and there are certain characteristics.There are three main features of the amber infrared spectra : the double absorption peak of C-H functional group stretching vibration is located in the range 2930,2830cm-1.The absorption peak caused by the bending vibrations of CH2-CH3 in 1460 cm-1 and 1383cm-1.The absorption peak caused by the vibration of C-O(carboxylic acid)at 1157 cm-1;Raman spectroscopy has three main features: the peak area located in the 2923cm-1~2865cm-1 region have multiple peaks due to C-H stretching vibration;located in the vicinity of 1445cm-1 due to C-H stretching vibration and peak;characteristic peak near 1640cm-1 due to C=C stretching vibration and the emergence of.Based on the gem characteristics and spectral characteristics of natural amber,the identification of amber imitations is summarized as follows: natural amber,optimized for the processing of amber,reconstituted amber,"second generation" amber and natural resin imitation amber are similar in the traditional gemological properties.Natural amber,optimized processing amber and reconstituted amber have the same infrared absorption spectrum.Some processing amber and natural amber have different microstructures.The "second generation" amber has the same characteristic absorption peak as the natural amber,while also the absorption peak of other materials.The absorption spectra of natural resins are in 3080cm-1,1000~ 800cm-1 intervals,and other infrared absorption spectra of natural amber.