DOI: 10.5281/zenodo.13913430
title: Database of elemental concentration of diopside in lapis lazuli rocks of different provenances obtained by micro-PIXE

description: Contents of the database: this database contains the results of the micro-Particle Induced X-ray Emission (u-PIXE) analysis of diopside crystals in lapis lazuli rocks. The samples are reference rocks with known origin and coming from different lapis lazuli mining areas (Afghanistan, Tajikistan, Siberia, Myanmar, Chile), procured by on-site geological expeditions, museum collections or international markets. The source of each rock is indicated in the data sheet. The data were collected during a long-term study started in 2007 by the Solid State Physics Group at the Department of Physics of the University of Turin (Italy) with the the aim of creating a non-invasive analytical protocol to investigate the provenance of lapis lazuli material used in artworks throughout history. The analysis was carried out over several years and in different facilities using accelerated proton microbeams; this information and some basic details about the measurament conditions (e.g. beam energy) are reported in the data sheet. The software used for data processing is GUPIXWIN or derivatives. The full description of the analysis methodology and the discussion of the results in terms of the development of a lapis lazuli provenance protocol can be found in: 

(Lo Giudice et al., 2017) Lo Giudice, A., Angelici, D., Re, A., Gariani, G., Borghi, A., Calusi, S., Giuntini, L., Massi, M., Castelli, L., Taccetti, F., Calligaro, T., Pacheco, C., Lemasson, Q., Pichon, L., Moignard, B., Pratesi, G., Guidotti, M.C., 2017. Protocol for lapis lazuli provenance determination: evidence for an Afghan origin of the stones used for ancient carved artefacts kept at the Egyptian Museum of Florence (Italy). Archaeol. Anthropol. Sci. 9, 637–651. https://doi.org/10.1007/s12520-016-0430-0

(Guidorzi et al., 2023) Guidorzi, L., Re, A., Magalini, M., Angelici, D., Borghi, A., Vaggelli, G., Fantino, F., Rigato, V., La Torre, L., Lemasson, Q., Pacheco, C., Pichon, L., Moignard, B., Lo Giudice, A., 2023. Micro-PIXE and micro-IBIL characterisation of lapis lazuli samples from Myanmar mines and implications for provenance study. The European Physical Journal Plus, 138(2), 175. https://doi.org/10.1140/epjp/s13360-023-03768-x

The characterisation of reference rocks is an ongoing activity of the group and further versions of this database will be updated as new data are collected. 
description: Contents of the PCA dataset: the PCA dataset reports the part of the database data that can be used to perform Principal Component Analysis to differentiate among four lapis lazuli provenances: Afghanistan (AFG), Tajikistan (TAJ), Myanmar (MYA) and Siberia (SIB). It contains only the elemental concentration values of those elements in diopside that are relevant for provenance discrimination (Ti, V, Cr, Mn, Sr, Zn). If the element was determined to be below the limit of detection, the LOD/2 value is reported in the dataset. The details of the application of PCA to lapis lazuli provenance investigation are reported in the following publication, where the approach was presented for the first time:

(Guidorzi et al., 2023b) Guidorzi, L., Re, A., Magalini, M., & Lo Giudice, A., 2023. Application of principal component analysis to µ-PIXE data in lapis lazuli provenance studies. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atom 540, 45-50. https://doi.org/10.1016/j.nimb.2023.04.007