Replication Data for: Hidden in the Glaze: Cobalt Blue Decorations of Catalan Tin-Glazed Ceramics from the 16th to 18th Centuries

Purpose
The dataset supports the archaeometric characterisation of cobalt blue–decorated tin-glazed ceramics from Catalonia (16th–18th centuries), with a specific focus on detecting arsenic in cobalt-based glaze pigments and assessing compositional changes in these pigments over time. It also aims to document technological variation in ceramic production through the comparison of bodies and glazes.

Nature
The dataset comprises (i) tables of bulk chemical composition of ceramic bodies, (ii) tables of chemical composition of glazes, and (iii) X-ray diffraction (XRD) data of ceramic bodies and of arsenate-bearing phases identified in cobalt-based pigments. These data are complemented by SEM–EDX and SEM–FIB microanalytical results, which provide phase identification and nanoscale evidence of arsenic-bearing inclusions. The dataset includes quantitative elemental ratios (e.g., CoO/NiO, CoO/FeO, CoO/MnO) and mineralogical identification of calcium–lead arsenate phases.

Scope
The dataset covers a diachronic series of Catalan tin-glazed ceramics dated from the 16th to the 18th centuries. It includes both ceramic bodies and glazes, enabling integrated analysis of compositional groups and technological evolution. The scope is limited to material characterization and phase identification and does not address provenance studies of raw materials beyond compositional and mineralogical classification.