Oxygen Content and Colour Change Characteristic of Blood Amber from Myanmar

The oxygen content and colour change characteristics of blood amber from Myanmar in different colours were nondestructively tested by Fourier transform infrared spectrometer and ultraviolet-visible spectrophotometer.The infrared spectroscopy testing results showed that the relative oxygen content of blood amber from Myanmar increases with its colour deepening, which suggests that the colour saturation was basically positively correlated with the oxygen content.With comparasion study of ultraviolet-visible spectra, the darker the colour of the samples, the closer its reflection curve inflection point is to the red end of the spectrum, i.e. the wavelength corresponding to the inflection point of the reflection curve appears "red shift" phenomenon; with the yellow tone deepening, the lightness increases, while the lightness decreases when the samples' colour transition from orange-ish red to brownish red. Combining the colour parameters of blood amber with oxygen content, it can be infered that the oxygen element is the main cause of the blood amber colour changes from orange-ish red to brownish red.