Characterization of Attic Black Gloss and its South Italian imitations by means of Grazing incidence XANES and XRF Analysis

A. KARYDAS; M. CZYZYCKI; JUAN JOSÉ LEANI; J. OSAN; C. CALIRI; A. MIGLIORI; P. ROMANO

Berlin

Workshop; Workshop on Quantitative Methods in X¬Ray Spectrometry of the European X-ray Spectrometry Association; 2017

European X-ray Spectrometry Association

Attic black gloss decorative layer on ceramics is the result of an ancient fabrication recipes introduced during the classical period in Athens (VIIV century BC) based on a three stages oxidation-reduction-oxidation firing process of an illitic clay enriched in iron [1]. Despite the structural complexity of the black gloss material, in the classical period several workshops operating in Sicily and Southern Italy attempted to imitate the manufacture technology. The attic black gloss technological features represent a milestone in the evolution of material culture that for decades has attracted the research interest aiming to clarify the manufacturing process, the use of raw materials, trade routes, the workshop practices, to accomplish authentic modern reproductions, but also to contribute in modern advanced ceramics technology [2-4]. For these reasons the analytical characterization of the black gloss requires the use of advanced, non-invasive spectroscopic methods. Recently, 3D Micro-XANES was applied to determine the Fe oxidation states and its coordination chemical environment within the black gloss decorative layer [3].In this work we present a new experimental methodology for the elemental and chemical characterization of the black gloss layer using synchrotron radiation at grazing incidence excitation conditions [5]. The experimental approach has been supported by Monte Carlo simulations [6] utilized to recommend an optimum grazing angular range that restricts the emitted X-ray radiation to a few tens of micrometers, i.e. within the black gloss layer only. The new analytical protocol was developed and validated at the IAEA synchrotron endstation facility jointly operated with Elettra Sincrotrone Trieste at the XRF beamline. Several original black gloss and imitation pottery fragments manufactured in Sicily and South Italy and well-documented were examined by means of XRF analysis at three different excitation energies and X-ray absorption near edge structure spectroscopy across the Fe K-edge. The quantitative analysis results obtained for the trace elements content and the formal oxidation state of Fe are discussed and compared with previous published data [3, 4], offering new insights about the provenance and the manufacturing technology of the black gloss across the Mediterranean area during the classical period.