Abstract:

A total of 13 thresholds composed of one or more blocks of alabaster (calcitic onyx alabaster) survive in situ at Vil- la A at Oplontis. The thresholds, which belong to Villa A’s original phase of construction in the middle of the first century BC, arguably represent the most spectac- ular example of alabaster-use to survive from the villas and houses preserved by the eruption of Mt Vesuvius in AD 79. This article presents the results of the minero-pe- trographic and isotopic studies carried out on samples from these thresholds to determine their source. While a number of quarry sources can now be ruled out, the actual quarry source still remains uncertain. The results reiterate the need for a thorough investigation and re-ex- amination of the sources of alabaster used in the Roman period in order to provide a comprehensive database of the alabaster quarries that may have been operating during Antiquity.