Lapis Lazuli Provenance Study by Means of Ionoluminescence and PIXE

Lapis Lazuli is one of the oldest precious stones, being used for glyptic as early as 7000 years ago: jewels, amulets, seals and inlays are examples of objects produced using this material. Only few sources of Lapis Lazuli exist in the world due to the low probability of geological conditions in which it can form, so that the possibility to associate the raw material to man-made objects helps to reconstruct trade routes. Since art objects produced using Lapis Lazuli are valuable, only non-destructive investigations can be carried out to identify the provenance of the raw materials. Ionoluminescence (IL) combined with PIXE/PIGE is a good candidate for this task. The IL/PIXE/PIGE capability to distinguish Chilean Lapis Lazuli from Afghan was demonstrated in previous preliminary papers [1,2]. Moreover, a more systematic study was performed on twelve Lapis Lazuli samples from four quarries (Afghanistan, Chile, Pamir and Siberia) using a multi-technique approach (optical microscopy, cold-CL and SEM-EDS-CL) that was propaedeutic to IL/PIXE/PIGE measurements. Despite the limited number of analyzed samples, results were promising and the experimental differences among different samples were significant [3]. In this work, a review on the lapis lazuli provenance study by means of ion beam analysis will be presented. New data on chemical composition and luminescence that could be useful to identify provenance will be also reported. [1] S. Calusi, E. Colombo, L. Giuntini, A. Lo Giudice, C. Manfredotti, M. Massi, G. Pratesi, E. Vittone. Nucl. Instrum. Meth. Phys. Res. B 266, 2306 (2008). [2] E. Colombo, S. Calusi, R. Cossio, L. Giuntini, A. Lo Giudice, P.A. Mandò, C. Manfredotti, M. Massi, F.A. Mirto, E. Vittone. Nucl. Instrum. Meth. Phys. Res. B 266, 1527 (2008). [3] A. Lo Giudice, A. Re, S. Calusi, L. Giuntini, M. Massi, P. Olivero, G. Pratesi, M. Albonico, E. Conz. Anal. Bioanal. Chem. 395(7), 2211 (2009).