Updates on the study of archaeological pigments

By Roxanne Radpour, Associate editor for archaeological pigments

A recent paper by A. Kostomitsopoulou Marketou, et al. (2020) titled “Egyptian Blue Pellets from the First Century BCE Workshop of Kos (Greece): Microanalytical Investigation by Optical Microscopy, Scanning Electron Microscopy-X-ray Energy Dispersive Spectroscopy and Micro-Raman Spectroscopy” is an in-depth investigation expanding the present understanding of Egyptian blue pigment production in antiquity. Most information on Egyptian blue production, relatively sparse compared to evidence of its existence, has predominantly come from Egyptian and Italian sites.  From an expansive 136 pellet collection, 18, which include both successful and unsuccessful pellet products, were sampled and underwent microchemical and morphological examination to explore production and processing practices. The discussion highlights several interesting results, based on grain size, morphology, and material phases: low alkali starting conditions; local sourcing for raw materials; possible re-firing of pellets; and variations of the production sequence such as possible introduction of a cobalt material and short firing times to control the final hue. Read further to see the in-depth results, discussion and open questions that this study prompts in the reverse engineering of ancient practices in pigment making. 

Figure 1. The Egyptian blue finds from the Koan workshop analysed in the present article.