Spectral and Colour Characteristics of Red Series Amber from Myanmar

The differences and connections between the spectra and colour characteristics of the red series amber from Myanmar were studied by non-destructive testing with Fourier transform infrared spectrometer, Raman spectrometer and ultraviolet-visible spectrophotometer, and the oxygen content, maturity and chromaticity parameters of red series amber from Myanmar were compared and analyzed.The results turn out that the infrared spectra, Raman spectra and ultraviolet-visible spectra of different varieties of amber from Myanmar show good uniformity, but different varieties also have certain differentiation in relative oxygen content, maturity, hue angle and dominant wavelength: the order of the relative oxygen content, from big to small, are blood amber, blood tea amber, brown red amber; the order of maturity, from big to small, are blood amber, brown red amber, blood tea amber; when the hue angle is between 54°-82° and the dominant wavelength is 570-590 nm, the amber is classified as brown red amber; when the hue angle is between 36°-54° and the dominant wavelength is 590-600 nm, the amber is classified as dark amber; when the hue angle is between 18°-36° and the dominant wavelength is 600-620 nm, the brown red amber is classified as blood amber, which can provide a theoretical basis for the classification of varieties and colour grading of the red series amber from Myanmar.