Characterization of azurite and lazurite based pigments by laser induced breakdown spectroscopy and micro-Raman spectroscopy

摘要

The most commonly used blue pigments in medieval manuscripts are azurite and lapis-lazuli. The first one is a copper-based pigments; the coloring compound of the latter is lazurite, a sodium silico-aluminate in a sulfur matrix. Knowledge of the chemical composition of the materials is essential for the study of oiiluminated manuscripts. In this paper, micro-Raman and LIBS have been used for the study of azurite and lapis-lazuli, as well as different mixtures of these pigments applied to parchment to simulate an illuminated manuscript. The results of our work show the importance of using more than one technique for a good comprehension of a manuscript. In particular, the opportunity of combining elemental information (obtained from laser induced breakdown spectroscopy) and vibrational spectroscopy information (obtained from Raman) will be fully exploited.