A Raman spectroscopic approach to the maturation process of fossil resins

Abstract

Raman spectra of a range of differently aged samples of natural resins (recent resins, copals, fossils resins from Tertiary to Early Cretaceous age) were taken for a comparative study of the age‐induced maturation processes of the resins. It can be shown that a decrease in band intensity at around 1640 cm−1 due to loss of ν(CC) stretching vibrations, together with other spectral details, is correlated with the increase in age of the resins. Copyright © 2001 John Wiley & Sons, Ltd.

Fourier transform Raman spectroscopic data on the fossil resin siegburgite

“…Based on the classification as a Class III resin (a natural polystyrene), 6 the spectra of the two different siegburgite samples were expected to differ from those of terpenoid resins. 15,16 Despite the fact that the sample from the 'Goitsche' produced a higher fluorescence background than the sample from the type locality Siegburg owing to its darker color, the major bands can still be observed and compared. The Raman spectra collected in this study proved the expected polystyrene character of the material, with their most striking bands at around 620 cm 1 , which was assigned to ring deformation, at 1002 and 1034 cm 1 , attributed to aromatic ring breathing and υ(CH) aliphatic and aromatic vibrations, and at 1603 and between 2850 and 3065 cm 1 , which were assigned to (C C) aromatic ring stretching and (CH 2 and (CH) vibrations, respectively.…”

“…The typical bands of terpenoid resins, with Bitterfeld amber as a representative sample in this study, can be seen at about 1446 and 1646 cm 1 . 15,16 The broken lines at 1446 and 1646 cm 1 for the terpenoid resins and the dotted lines at 620, 1002, 1034 and 1602 cm 1 for polystyrene are included as a visual aid for the reader.…”

“…An additional band at 1727 cm 1 occurs weakly in siegburgite and fairly strongly in the measured polystyrene pendant, also documented in other investigations. 15,17,18 In contrast, neither of these bands occur in the measurements of a polystyrene standard (Aldrich #18, 243-5) presented on the Homepage of the McCreery Research Group, 19 nor in polystyrene Raman spectra in the Spectra Online Database 20 or in measurements presented in the Caltech Mineral Spectroscopy Server. 21 Further slight differences can be observed in the region between 2900 and 2945 cm 1 .…”

Raman Spectroscopy of cultural heritage Materials: Overview of Applications and New Frontiers in Instrumentation, Sampling Modalities, and Data Processing

“…These materials are based on a terpene skeleton (diterpene) with carbon-carbon double bonds highly sensitive to oxidation [206]. To monitor these changes, the ratio of the intensities of the C=C stretching band (1650 cm -1 ) to the C-H bending band (1445 cm -1 ) is performed: the higher the ratio, the more advanced the degradation [32,107,126,307]. However, these studies differ in how they interpret this evolution.…”

Fourier transform Raman spectra of Czech and Moravian fossil resins from freshwater sediments

“…Later it was confirmed that fossil resins with a higher degree of maturity display values of this ratio <1, compared with immature resins (copals), for which these values are >1. 4,12,13 .…”