RAMAN μ-SPECTROMETRY, A UNIQUE TOOL FOR ON-SITE ANALYSIS AND IDENTIFICATION OF ANCIENT CERAMICS AND GLASSES

Abstract

ABSTRACTRaman micro-spectroscopy allows remote, non-destructive analysis of materials. Our laboratory was among the first to apply this technique to frescoes, oil and parchment painting. For five years we have focused our efforts on horn, ivory, tortoise shell and ancient ceramics and glasses. Crystalline and amorphous phases can be identified in both body and surface layer, including the glaze/glass-coloring nanosized pigments (e.g. in lustre ware, the first nano-optic device). Recent generation instruments are portable, which allows for on-site examination, for example, in a museum. In nanostructured, nanocrystalline/amorphous silicate glasses, glazes and most of their pigments, Raman parameters and their multivariable analysis are used to recognize compositions as well as to classify them as a function of their processing. This overview addresses the procedure, choice of the exciting radiation, control of the Raman resonance, data processing and extraction of relevant parameters such as the index of polymerization and different signatures that may be characteristic of specific glazes and pigments. Didactic examples are chosen among pottery that representative of the different production technologies used in the Roman, European (Medici, Meissen, Chantilly, Mennecy, Saint-Cloud, Sèvres), Islamic (Iznik, Kütahya, Safavid) and Asian (Vietnam) worlds.