A review of the non-destructive identification of diverse geomaterials in the cultural heritage using different configurations of Raman spectroscopy

Non-destructive Raman microscopy (RM) applied to geomaterials in the cultural heritage is reviewed by means of explaining selected examples representative of the different kinds of geomaterials that can be characterized and of the different kinds of analytical configuration that can be employed. To explain the versatility and considerable analytical potential of RM that result from its unique combination of capabilities,the first sections summarize the theory and practice of the method and its advantages and disadvantages. The most modern configurations (mobile RM (MRM) and ultra-mobile RM; micro-mapping and imaging; telescopy) are described. Applications in the new age of 'don't move it, don't even touch it' archaeometry have previously been classified into 10 domains, seven of which concern geomaterials: gems; rocks; ceramics; corroded metals; coloured vitreous materials; and mineral pigments on an inorganic or organic substrate. The representative examples here include all these domains and cover the time range from Prehistoric through Egyptian, Roman, Meso-American, Medieval, Chinese, Renaissance and Mogul cultures to modern colouring of glass and a contemporaneous simulation of submarine archaeology.