Natural ultramarine in the Roman context of Volsinii (Bolsena, Italy): a multianalytical characterization

• Abstract:

  This study presents a comprehensive analysis of a blue pigment lump discovered near Volsinii (modern Bolsena, Italy), employing ED-XRF, micro-Raman spectroscopy, and XRPD techniques. The pigment was conclusively identified as natural lazurite, the primary component of lapis lazuli. ED-XRF analyses, supported by principal component analysis, revealed elemental compositions aligning closely with synthetic ultramarine pigments, yet distinct from Egyptian and Herculaneum blues. Micro-Raman spectroscopy detected characteristic S3⁻ radical peaks at 548 cm⁻¹, with additional shoulders at 585 cm⁻¹ indicative of natural origin. XRPD confirmed a predominantly lazurite crystalline structure, lacking kaolinite impurities typical of synthetic variants. The presence of such a rare and valuable pigment in a provincial Roman context suggests sophisticated material procurement and artistic practices, challenging prevailing assumptions about pigment distribution in antiquity.
• Download:

  IMEKO-Metroarchaeo-2025-036.pdf
• DOI:

  tc26-2025.036

Event details:

• IMEKO TC:

  TC26
• Event name:

  TC26 MetroArcheo Conference 2025
• Title:

  Metrology for Archaeology and Cultural Heritage

• Place:

  Bergamo, ITALY
• Time:

  15 October 2025 - 17 October 2025