The rise and fall of antimony: Sourcing the “colourless” in Roman glass

Abstract

Antimony (Sb), a metalloid, is considered a rare occurence in the archaeological record. Though Sb ores are scarce they were utilised over several millennia for a variety of applications from copper alloys to glass and glaze. In particular, they were used for opacifying or decolouring glass and glazes. Amongst Sb minerals, only stibnite can achieve, in a controlled manner, the desired effect as a decolourizer or opacifier. Mass production of Sb-decoloured natron glass seemingly halts close to the time that Dacia is lost to the Roman empire. The use of Sb as an opacifier soon follows suit, with Sn replacing it. In this paper we investigate the possibility that the disappearance of Sb-decoloured glass production is linked to the loss of access to the mines of Dacia. Lead and re-evaluated Sb isotopic analyses show that the most likely sources of stibnite for late Roman Sb-decoloured natron glass are indeed the stibnite mines of Dacia.