Reflections into Ptolemaic Glass, III: Understanding Glass Forming, Glass Colouring, and Furnace Conditions in Secondary Workshops

The production techniques used in creating Ptolemaic glass inlays have fascinated researchers for decades, yet a comprehensive understanding remains elusive due to limited contextual data from well-excavated secondary workshops. This paper presents an in-depth investigation into glass forming, glass colouring, and furnace conditions, drawing on extensive archaeological research and chemical analyses of materials unearthed at the site of Tebtunis (Fayum Oasis) and from comparative datasets. Through the use of optical microscopy (OM), confocal laser scanning microscopy (CLSM), and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), we offer insights into the chunk-gathering technique employed for inlay forming and reconstruct the sequential steps involved in producing miniature mosaic glass figures. Our study also presents compelling evidence that glass colouring did indeed take place within secondary workshops during the Ptolemaic Period. We further highlight the technological skill of ancient Egyptian artisans by discussing the delicate interplay of temperature and redox conditions required to achieve specific hues. By analysing relics of the raw material, newly formed mineral phases, and colouring/opacifying agents, we provide a clearer understanding of the glass colouring processes. Overall, this research significantly advances our knowledge of ancient glass technology, illuminating its complexity and importance during the Ptolemaic Period and laying a crucial foundation for future studies on the rich history of the ancient Egyptian glass industry.