Correlation between the results obtained by spectroscopic analyses on Baltic amber samples and different types of artificial ageing. Using FT-Raman spectroscopy, an increase in concentration of Cdouble bond; length as m-dashC bonds due to depolymerisation is revealed at a deep level below the surface of an amber sample after moderately accelerated ageing, e.g., thermal ageing at 70 °C for 35 days. In contrast, a decrease in concentration of Cdouble bond; length as m-dashC bonds due to oxidation is detected at the same depth after highly accelerated ageing, e.g., thermal ageing at 100 °C for 30 days or photoageing for 17 days. In both cases, progression of oxidation is confirmed by ATR-FTIR spectroscopy at a shallower depth on a micrometre-scale. Real vertical proportions are modified for better readability of the image.