deustum

Deustum refers to a specific type of glass found in archaeological contexts, particularly associated with the Roman period. This term is derived from the Latin word "deustus," meaning burnt or scorched, reflecting the appearance of the glass itself. Deustum glass is characterized by its mottled or streaky appearance, often with darker, semi-opaque patches interspersed with lighter, translucent or transparent areas. This distinctive look is not a result of intentional decorative techniques but rather a consequence of the manufacturing process and the raw materials used.

The composition of deustum glass typically includes a higher proportion of impurities, such as iron oxides and alkalis, compared to purer Roman glass. During the firing process at high temperatures, these impurities react and stratify, creating the characteristic variegated pattern. While some scholars have debated the exact causes and implications of this coloration, it is generally understood as an indicator of less refined glass production. Deustum glass has been found in various forms, including fragments of vessels, beads, and other small objects. Its presence can provide archaeologists with clues about the technological capabilities, economic conditions, and trade networks of the Roman era. The study of deustum glass contributes to our understanding of ancient glassmaking practices and the evolution of glass technology.