On the functionality of vasa diatreta: The case of the cage cup fragments from Gorsium

Abstract

This study re-evaluates the functionality and production context of Roman cage cups (vasa diatreta) through recently analysed fragments from Gorsium (Tác, Hungary), found in the apsidal audience hall of a Late Roman palace. The architectural setting, with clear administrative-imperial connotations, confirms the ceremonial use of these luxury vessels by high-ranking officials. The presence of multiple cage cup fragments in a single representative room is particularly notable, indicating that such elite objects were not isolated rarities but could also be used in official receptions, thus redefining their social function.

Archaeometric analysis has confirmed that their composition reveals unusually low levels of iron, magnesium, and potassium, suggesting the use of exceptionally pure, low-impurity sand—a possible indicator of deliberate material selection in elite production contexts. 

Evidence from Gorsium provides rare insights into the interplay of luxury, recycling, and imperial display in the Late Roman provinces. It challenges traditional distinctions between high craftsmanship and reused materials, and affirms the adaptive sophistication of Roman glass economy.