A New Two-Step Approach to Studying Early Medieval Lustre Ceramics from Sudan: Minimizing Destructiveness by Preliminary Micro-X-Ray Fluorescence Analysis

The present study introduces a novel two-step multi-analytical approach for studying lustre ceramics, aiming to minimize damage to valuable artifacts. The method combines a completely non-destructive preliminary micro-X-ray fluorescence (micro-XRF) analysis, providing semi-quantitative information and elemental mapping, with micro-destructive transmission electron microscopy (TEM) for detailed nanoparticle (NP) morphology studies on selected areas. Diffuse reflectance spectroscopy (DRS) is also employed as a non-destructive method to quantify lustre colour. This approach was applied to 20 samples of 9th- to 12th-century AD lustre ceramics from the Deraheib site in Northern Sudan. The research aimed to verify the lustre technique, characterize lustre properties (nanoparticle size, colour), and identify the ceramic production center based on glaze composition. The results from micro-XRF and TEM confirmed the presence of silver (Ag) and copper (Cu) in the lustre, with Ag NPs having a median size of 8 nm. Semi-quantitative micro-XRF analysis of the glaze indicated a composition rich in lead and tin oxides (PbO and SnO2, 5%–15%) and magnesium oxide (MgO, 3%). This composition strongly correlates with published data for lustre ceramic production in Basra, Iraq, suggesting it as the likely origin, and ruling out Fustat, Egypt.