Trachyte of the Euganean Hills is a subvolcanic porphyritic rock historically used as carving and building stone in northern and central Italy–primarily from Roman times onward–with the first evidence of its use dating back to prehistory. The numerous quarries and very similar trachyte varieties, as well as thewidespread use of this stone, create several problems in defining its provenance for archaeological and historical materials. New petrographic and geochemical tracers for recognizing the provenance quarry of Euganean trachyte are presented here, providing a Comprehensive reference database for archaeometric studies. The petrographic markers principally include quantitative data on mineralogical composition and textural features of phenocrysts and groundmass, determined by image analysis of chemical maps acquired by micro X-ray fluorescence and scanning electron microscope-energy-dispersive X-ray spectroscopy; particular use has been made of data on the abundance and grain-size distribution of feldspar phenocrysts, phenocrysts-groundmass ratio, content of SiO2 phases in the groundmass, and the arrangement and grain-size of microlites in the matrix. The geochemical tracers involve composition of bulk rock and phenocrysts, determined by X-ray fluorescence and laser ablation inductively coupled plasma mass spectrometry, respectively; quarry recognition can be achieved using plots built from concentrations of major and trace elements, with mineral-scale chemistry being the most effective and precise discriminant property, especially in the case of biotite and, secondarily, augite, kaersutite, and magnetite

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This paper presents new developments on the provenance study of lapis lazuli started by our group in 2008: during the years a multi-technique approach has been exploited to obtain minero-petrographic characterization and creation of a database considering only rock samples of known provenance. Since the final aim of the study is to develop a method to analyze archeological findings and artworks made with lapis lazuli in a completely non-invasive way, ion beam analysis techniques were employed to trace the provenance of the raw material used for the production of artifacts. Continuing this goal and focusing the analysis on determination of more significant minero-chemical markers for the provenance study of trace elements in different minerals, the method was extended with the use of micro X-ray fluorescence (µ-XRF), to test the potential of the technique for this application. The analyzes were focused on diopside and pyrite in lapis lazuli samples of known provenance (Afghanistan, Tajikistan, and Siberia). In addition, µ-XRF data were compared with micro proton-induced X-ray emission (µ-PIXE) results to verify the agreement between the two databases and to compare the analytical performance of both techniques for this application.

The serpentine minerals lizardite, polyhedral serpentine, chrysotile, antigorite and 15-sector and 30-sector polygonal serpentine have been studied by micro-Raman spectroscopy, using selected samples, that had been previously characterized. The appropriate crystal orientations were determined by optical microscopy of petrographic sections. Oriented spectra, obtained using Nd-YAG green laser radiation (532 nm), were deconvolved, extracting wavenumber and intensity values for the peaks, possibly overlapping and forming complex bands. Relevant Raman anisotropy is common and relevant in serpentine. Depending upon the orientation of the impinging laser, significant wavenumber shifts occur (up to 10 cm À1 , mostly in polyhedral serpentine and lizardite). Furthermore, also, important intensity variations (up to 1 order of magnitude) occur in polyhedral serpentine, lizardite, chrysotile and antigorite as well. On the one hand, the possibly characteristic peaks have been identified and discussed. On the other hand, caution is suggested as far as the micro-Raman characterization of polyphasic, variably oriented serpentine minerals is concerned.

Quantitative micro-PIXE and electron microprobe analyses, as well as micro-PIXE compositional mapping of trace elements were performed on monazite [(Ce, La, Nd, Th)PO 4 ] inclusions in pyrope megablasts from Dora Maira Massif, Western Italian Alps for petrological and geochronological purposes.Monazite was studied by SEM-BSE imaging and by X-ray qualitative compositional maps of major elements; further WDS electron microprobe analyses were carried out in areas showing different BSE intensity in order to quantify chemical zoning. Finally, micro-PIXE compositional maps and quantitative analyses were performed on selected spots and areas. EPMA data indicate that the Dora Maira monazite is Ce-and Th-rich with homogeneous concentrations of LREE, but with a significantly heterogeneous distribution of Th, as well as of Y, Sr, U and Pb as displayed by micro-PIXE compositional mapping. HREE mostly occur in concentrations below the detection limit for standard quantitative EPMA. Th-U-Pb zoning suggests two monazite growth events, dated at 35 (AE7 Ma) and 60 Ma (AE10 Ma), respectively. While the younger age of 35 Ma found in high-Th monazite areas corresponds to the thermal and baric peak of the UHP metamorphism in the Dora Maira Massif, in agreement with previous literature data, the older ages of 60 Ma found in low-Th areas have to be confirmed by U-Th-Pb isotopic data.

This paper presents a μ-XRF analytical approach for a non-destructive study of Cultural Heritage glass finds. This technique can be used for quantitative analysis of small volumes of solid samples, with a sensitivity that is superior to the electron microprobe but inferior to an ICP-MS system. An experimental set-up with natural and synthetic glass standards is proposed here for the quantitative analyses of major and trace elements on glass objects which cannot be sampled such as small archaeological or historical artefacts from Cultural Heritage. The described method, performed by means of the commercial μ-XRF Eagle III-XPL, was applied to Islamic glass specimens of Sasanian production (III-VII century A.D.) previously analyzed by ICP-MS and SEM-EDS techniques (P. Mirti, M. Pace, M. Negro Ponzi and M. Aceto, Archaeometry, 2008, 50(3), 429-450; P. Mirti, M. Pace, M. Malandrino and M. Negro Ponzi, J. Archaeol. Sci., 36, 1061-1069; and M. Gulmini, M. Pace, G. Ivaldi, M. Negro Ponzi and P. Mirti, J. Non-Cryst. Solids, 2009, 355, 1613-1621) and coming from the archaeological site of Veh Ardasir in modern Iraq. Major elements (Na, Mg, Al, Si, K, Ca, Fe) of glass specimens show an accuracy better than 5%. Trace elements (Cr, Mn, Sr and Zr) display an accuracy better than 5% when the checked elements have a concentration >100 ppm by weight, whereas it is around 10% with a concentration <100 ppm by weight. μ-XRF is, therefore, a suitable elemental analysis technique for the non-destructive study of small glass finds due to its relatively good accuracy, reproducibility and low detection limits (∼tens ppm).

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