1 Structural and Chemical Heterogeneity in Ancient Glass Probed using Gas Overcondensation, X-ray Tomography, and Solid-state NMR Sean P. Rigby a, *, Lee Stevens a , Thomas Meersmann b,c , Galina E. Pavlovskaya b , Gregory J. Rees b,d , Julian Henderson e , Saffron J. Bryant f , Karen J. Edler f , Robin S. Fletcher g a Department of Chemical and Environmental Engineering, University of Nottingham, NG7 2RD, UK. b Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, NG7 2RD, UK c University of Nottingham, Ningbo campus, 199 Taikang E Rd, Yinzhou, Ningbo, Zhejiang, China d Department of Materials, University of Oxford, Oxford, UK e Department of Classics and Archaeology, University of Nottingham, University Park, Nottingham, NG7 2RD, UK f Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK g Johnson Matthey, P.O. Box 1, Belasis Avenue, Billingham, Cleveland, TS23 1LB, U.K .