Characterization Of Ancient Pottery Clay By Xrf Spectrometry - Sample Preparation And Calibration Curve -

X-ray fluorescence spectrometry is used for the routine analysis of ancient pottery. Nevertheless, there are few studies concerning to reliability of the quantitation in the literature. For X-ray fluorescence quantitation of the pottery, the importance of sample preparation was reported and then the calibration curve was optimized. First, sample conditions suitable for the quantitation were estimated based on escape depth of fluorescent X-rays. Additionally, three pottery specimens (unprepared pottery, powder pellet and glass bead) made from one pottery shard were measured for comparisons among the relative standard deviations of fluorescent X-rays. Next, synthetic calibration standards were prepared by compounding chemical reagents (oxides, carbonates, and diphosphate) to construct calibration curves for 10 major oxides (Na2O, MgO, Al2O3, SiO2, P2O5, K2O, CaO, TiO2, MnO, and total-Fe2O3) and 12 minor elements (V, Cr, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, and Pb). The standards were produced by imitation of the chemical compositions of Japanese pottery. The calibration curves drawn by measurements of the standards were validated by assaying three geochemical reference materials. The present quantitation technique was applied for measurement of Jomon pottery and clay samples from Nakatai site, Aomori, Japan. Additionally, the 22 components in the reference materials and the archeological samples were determined by semi-fundamental parameter calculations. The analytical results from the present method were compared with those from the semi-fundamental parameter method.