A XANES study of chromophores: the case of black glass

We studied the Fe K-edge X-ray absorption near edge (XANES) spectra of several Roman black glass fragments in order to determine the Fe3+/ΣFe ratio of these materials. The selected archaeological glass samples cover the period 1st–5th century AD in nine different sites of the North Western provinces of the Roman Empire. The fragments belong to two different compositional groups demonstrating a diachronic evolution: early Roman HMG (High Magnesia Glass) and Roman Imperial LMG (Low Magnesia Glass). The first group contains natural Fe levels (below 2 wt% as Fe2O3), while the LMG has concentrations above 5 wt%. This difference is also reflected by Fe3+/ΣFe values. Low iron glass was produced under strongly reducing conditions in order to obtain the black colour, with average Fe3+/ΣFe values ≈ 0.17. LMG glass is somewhat more oxidised (Fe3+/ΣFe ≈ 0.4–0.5). While HMG glass required active control of the furnace environment, LMG was made under ambient atmosphere and its higher oxidation degree is mainly determined by the chemistry of the raw glass.

[1]  Koen Janssens,et al.  Deeply colored and black-appearing Roman glass: a continued research , 2014 .

[2]  M. Abuin,et al.  XAS study of Mn, Fe and Cu as indicators of historical glass decay , 2013 .

[3]  R. Arletti,et al.  A XANES study of chromophores in archaeological glass , 2013 .

[4]  K. Janssens.  Modern Methods for Analysing Archaeological and Historical Glass: Janssens/Modern , 2013 .

[5]  E. Brunet,et al.  Thermodynamic modeling of redox equilibria in sodium silicate glasses with low iron content , 2012, Russian Journal of Inorganic Chemistry.

[6]  D. Neuville,et al.  Effects of the Iron Content and Redox State on the Structure of Sodium Borosilicate Glasses: A Raman, Mössbauer and Boron K‐Edge XANES Spectroscopy Study , 2012 .

[7]  R. Arletti,et al.  XANES, UV-VIS and luminescence spectroscopic study of chromophores in ancient HIMT glass , 2011 .

[8]  P. Colomban,et al.  A Raman spectroscopic study of glass trade beads excavated at Mapungubwe hill and K2, two archaeological sites in southern Africa, raises questions about the last occupation date of the hill , 2011 .

[9]  Behzad Mehdikhani,et al.  Effect of Batch Melting Temperature and Raw Material on Iron Redox State in Sodium Silicate Glasses , 2011 .

[10]  Koen Janssens,et al.  DEEPLY COLOURED AND BLACK GLASS IN THE NORTHERN PROVINCES OF THE ROMAN EMPIRE: DIFFERENCES AND SIMILARITIES IN CHEMICAL COMPOSITION BEFORE AND AFTER ad 150* , 2009 .

[11]  Daniele Giordano,et al.  Micro-Raman determination of iron redox state in dry natural glasses: Application to peralkaline rhyolites and basalts , 2009 .

[12]  S. Sutton,et al.  Oxidation state of iron in komatiitic melt inclusions indicates hot Archaean mantle , 2008, Nature.

[13]  G. Pratesi,et al.  Yellow impact glass from the K/T boundary at Beloc (Haiti): XANES determination of the Fe oxidation state and implications for formation conditions , 2008 .

[14]  S. Phanichphant,et al.  Influence of glass basicity on redox interactions of iron-manganese-copper ion pairs in soda-lime-silica glass , 2008 .

[15]  Paul Bingham,et al.  Roman blue-green bottle glass: chemical–optical analysis and high temperature viscosity modelling , 2008 .

[16]  Philippe Colomban,et al.  A Raman spectroscopic study of the Mapungubwe oblates: glass trade beads excavated at an Iron Age archaeological site in South Africa , 2008 .

[17]  J. M. Parker,et al.  Local structure and medium range ordering of tetrahedrally coordinated Fe3+ ions in alkali–alkaline earth–silica glasses , 2007 .

[18]  P. Nicholson.  Brilliant things for Akhenaten: the production of glass, vitreous materials and pottery at Amarna site O45.1 , 2007 .

[19]  Caroline Jackson,et al.  MAKING COLOURLESS GLASS IN THE ROMAN PERIOD , 2005 .

[20]  M. Riccardi,et al.  The ancient glass production of the Medieval Val Gargassa glasshouse: Fe and Mn XANES study , 2005 .

[21]  M Newville,et al.  ATHENA, ARTEMIS, HEPHAESTUS: data analysis for X-ray absorption spectroscopy using IFEFFIT. , 2005, Journal of synchrotron radiation.

[22]  F. Farges,et al.  The effect of redox state on the local structural environment of iron in silicate glasses: A combined XAFS spectroscopy, molecular dynamics, and bond valence study , 2004 .

[23]  V. Kilikoglou,et al.  ROMAN GLASS‐MAKING AT COPPERGATE, YORK? ANALYTICAL EVIDENCE FOR THE NATURE OF PRODUCTION* , 2003 .

[24]  G. Pratesi,et al.  Iron oxidation state in the Fe‐rich layer and silica matrix of Libyan Desert Glass: A high‐resolution XANES study , 2003 .

[25]  K. D. Jayasuriya,et al.  XANES calibrations for the oxidation state of iron in a silicate glass , 2003 .

[26]  J. Crum,et al.  Mössbauer and optical spectroscopic study of temperature and redox effects on iron local environments in a Fe-doped (0.5 mol% Fe2O3) 18Na2O–72SiO2 glass , 2003 .

[27]  P. Petit,et al.  Oxidation state and coordination of Fe in minerals: An Fe K-XANES spectroscopic study , 2001 .

[28]  N. I. Min’ko,et al.  Effect of the redox potential of the glass batch and cullet on the tinting of industrially produced glass containing iron oxides , 2000 .

[29]  K. Hodgson,et al.  A Multiplet Analysis of Fe K-Edge 1s → 3d Pre-Edge Features of Iron Complexes , 1997 .

[30]  J. Duffy.  Redox equilibria in glass , 1996 .

[31]  M. T. Coolbaugh,et al.  Compositional dependence of redox equilibria in sodium silicate glasses , 1994 .

[32]  Marie-Dominique Nenna,et al.  Excavations at Jalarne Site of a Glass Factory in Late Roman Palestine, G. Davidson Weinberg ed., 1988 , 1991 .

[33]  Robert H. Brill,et al.  IRON AND SULFUR RELATED COLORS IN ANCIENT GLASSES , 1984 .

[34]  C. Wells.  Excavations at Carthage, Northern Sector, 1981 , 2018 .

[35]  B. Mysen,et al.  Curve-fitting of Raman spectra of silicate glasses , 1982 .

[36]  C. Ray Bamford,et al.  Colour Generation and Control in Glass , 1977 .

[37]  E. Sayre,et al.  Compositional Categories of Ancient Glass , 1961, Science.