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This is the final blog post highlighting the release of Oplontis: Villa A (“of Poppaea”) at Torre Annunziata, Italy. Volume 2. The Decorations: Painting, Stucco, Pavements, Sculptures. Thanks to series editors John R. Clarke and Nayla K. Muntasser for contributing these blog posts.

The first blog post, “Rediscovering and E-publishing the Foremost Luxury Villa Buried by Vesuvius”, introduced the history of the Oplontis Project and contextualized the work represented in the publications. The second provided an overview of the chapters that focused on the frescoes highlighting the variety of approaches, from forensic pigment analysis to cataloguing, reconstructions or interpretation. The third offered an overview of the chapters on sculptures studied at Villa A. In the next blog post. Dr. Muntasser discussed the stucco decorations at Villa A. The last post detailed the information on the pavements found in Villa A.

This time, Nayla Muntasser discusses the scientific analyses completed during the work on Villa A, providing an interesting look into the intersection of the humanities and natural sciences. Volume 2 is the second of three open access publications in a series offered exclusively by ACLS Humanities E-Book live on the Fulcrum platform. Find more resources below.

Note: All images in the post can be viewed in a gallery at the bottom of the page as well.


The scientific analyses of materials formed part of the original mission of the Oplontis Project, that is, the goal to conduct a systematic, multidisciplinary study of Villa A (“of Poppaea”) at Torre Annunziata, Italy. In both volumes of this series on Villa A, the chapters that rely on scientific research provide a deeper understanding of the particulars of the site. Since Volume 1 was devoted to the setting of the Villa, the scientific studies focused on topography, fauna and flora. Geological cores commissioned by the Oplontis Project revealed the line of ancient coast and showed that Villa A was perched high on a cliff (Volume 1, Chapter 3, Giovanni Di Maio). Botanical studies compared the painted images of animals and plants to the natural environment of the region, concluding that most of the real creatures and plants depicted were common to the area (Volume 1, Chapters 7 and 8, Massimo Ricciardi). Paleobotanical investigations focused on carbonized wood remains and pollen from the gardens and were undertaken by two teams led by scientists from the University of Naples (Volume 1, Chapter 9, Gaetano di Pasqale et al., and Chapter 10, Elda Russo Ermolli et al.). Analysis of the carbonized wood remains established that the gardens at Oplontis contained ornamental species of trees and bushes common to the Mediterranean region. Pollen analysis confirmed that the flora within the villa gardens was also typical, but what the pollen samples also showed was that, at the time of the eruption in 79 CE, the gardens were overrun with wild trees and bindweed vines, plants that take over when gardens are in a complete state of neglect.

Fig. 1. Professor. P. Baraldi and team member analysing pigments. Photo: P. Baraldi

In Volume 2 the scientific studies also revealed this combination of shared regional characteristics and differing particular features. The analyses of the pigments used in the frescoes was undertaken by Pietro Baraldi and his team from the University of Modena during the 2007 and 2009 seasons (Volume 2, Chapter 11). The analysis of the stones and marbles used in the architectural elements and the sculptures was the work of Simon Barker and J. Clayton Fant who studied the marbles in 2010 and incorporated the results of the stone provenance analysis carried out by Donato Attanasio at the Institute of Structure of Matter in Rome (Volume 2, Chapter 17).

Pigment analysis

The scientific analysis of pigments used in the frescoes can lead to a greater understanding of how  the paintings were created, how they were altered over time and whether workshops identified by expert visual means are reflected in the materials and techniques used. The intense focus on the walls also provides an opportunity to monitor the state of the paintings after so many years of exposure to light, air and tourists and to identify areas that require conservation.

Fig. 2. Portable Raman spectroscopy equipment used by Professor Baraldi. Photo: P. Baraldi

Baraldi used three types of instruments that allow for a non-destructive approach: a digital microscope connected to a computer, instrumentation using a Wood’s lamp with ultraviolet radiation, and a portable Raman microscope. The Digitus optical microscope with internal white light allowed for magnification from 10 to 220 times, enabling Baraldi to observe the morphology of the pigment granules on all the walls, an important step in itself, but also as a preliminary to spectroscopic investigation (Fig. 1). Ultraviolet radiation indicated the presence of organic materials in the observed surface, including environmental effects and interventions that might have taken place over time. Raman spectroscopy, a chemical analysis technique for identifying molecular and crystallographic characteristics of pigment without touching the painted surface, was used for research at the site focusing on eleven rooms (Fig. 2). More intensive analysis using a Horiba Jobin Yvon’s LabRAM was then carried out at the lab at the University of Modena on 75 microscopic samples taken from nine representative rooms (Fig. 3).

 

 

(Below) Fig. 3. Raman spectrum from sample 7 in room 20. Graph: P. Baraldi.  Egyptian blue on the bottom, amorphous hematite and magnetite on the top.

Consistent with the findings in Volume 1, Villa A shared many characteristics with other decorated villas in the region. The pigments used were naturally occurring yellow and red ochre, green earth (terra verde), calcite (white), charcoal and cinnabar red (mercury sulfide), and the synthetic Egyptian blue (calcium copper silicate). Initial observations led Baraldi to use Egyptian blue and cinnabar red as diagnostic pigments, because although they were the most expensive, they were widely used to vivify other colors. For example, Egyptian blue was used to brighten whites and greens and, intermixed with the plaster under-layer, to intensify the fresco colors (Fig. 4a; Fig. 4b). Thus while in some ways wall paintings at Villa A were representative of a certain type of residence along the Bay of Naples, the use of Egyptian blue as an enhancer of whites was not a common feature in the Vesuvian region. This study of the pigments provides a more nuanced picture of workshop techniques and patrons’ preferences than existed before.

Marble and stone analysis

The identification of marble provenance for specific artifacts or groups of artifacts is important for understanding the economic, social, and political role that marble and marble quarries played in the Roman world.

In their report on the provenance of black and white marbles from Villa A, Barker and Fant obtained the variables used for the characterization of the marbles from a combination of analytical techniques based on mineralogical-petrographic data, including Carbon-Oxygen stable isotopic analysis, Electron Paramagnetic Resonance (EPR) spectroscopy, and petrographic analysis of the samples. Because it is almost impossible to distinguish the quarry source for white marbles visually, Donato Attanasio performed the petrographic, spectroscopic (EPR), and isotopic analysis on 30 samples of white marbles from several sculptures and capitals among the collection (Fig. 5). Barker and Fant brought the total number of samples to 57, adding the analysis of the black marbles of the columns that originally supported Portico 60. The complete list can be found in Table 17.3 of their chapter in Volume 2. Determining the provenance of the marble samples involved measuring physical and chemical properties and comparing their numerical values with the results available from a database of quarry samples from known source sites.

Fig. 5. Statistical data of the white marble sculptures sampled showing quarry sites as possible provenances. Diagram: D. Attanasio

The authors chose a cross-section of the types and uses of marble from Villa A, including a fountain base, capitals, column bases, column shafts, thresholds, windowsills and statuary. The varieties of marble used at Villa A appear to fit with local trends in marble use, much as the pigments used in the fresco paintings fit within the general pattern of regional practices. However, beyond this broad conclusion, the scientific analyses established that most of the architectural white marble at the Villa was Luna marble from Carrara and not from ancient Dokimeion, as had been initially thought. In the case of the sculptures, however, a significant proportion of the 13 sampled were Greek marbles (Pentelikon and Paros), while the rest were Luna.

The scientific analyses of materials used in the decorations of Villa A confirmed some established views but more importantly, it provided fresh insights for scholars to contemplate.


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