Natural organic substances are involved in many aspects of the cultural heritage field. Their presence in different forms (raw, heated, mixed), with various conservation states, constitutes a real challenge
regarding their recognition and discrimination. Their characterization usually involves the use of
separative techniques which imply destructive sampling and specific analytical preparations. Here we
propose a non destructive approach using FT-Raman and infrared spectroscopies for the identification
and differentiation of natural organic substances. Because oftheir related functional groups, they usually
present similar vibrational signatures. Nevertheless the use of appropriate signal treatment and
statistical analysis was successfully carried out to overcome this limitation, then proposing new objective
discriminating methodology to identify these substances. Spectral decomposition calculations were
performed on the CH stretching region of a large set of reference materials such as resins,oils,animal
glues, and gums. Multivariate analyses ( Principal Component Analyses) were then performed on the
fitting parameters, and new discriminating criteria were established. A set of previously characterized
archeological resins, with different surface aspects or alteration states, was analyzed using the same
methodology.These testing samples validate the efficiency of our discriminating criteria established on
the reference corpus. Moreover,we proved that some alteration or ageing of organic materials is not an
issue to their recognition.