Chemical and Petrographic Characterization of Stone and Glass Tesserae in the Nereid and Geometric Mosaics from the S. Aloe Quarter in Vibo Valentia–Calabria, Italy

Donatella Barca,Armando Taliano Grasso,Elia Fiorenza,Marianna Musella,Fabrizio Sudano,Emilia Le Pera,Maria D’Andrea

doi:10.3390/min9120729

Donatella Barca, Armando Taliano Grasso + Show 5 more

Open Access

https://doi.org/10.3390/min9120729

Copy DOI

Journal: Minerals	Publication Date: Nov 26, 2019
Citations: 6	License type: CC BY 4.0

Affiliation: University of Calabria, Museo Civico di Zoologia

Abstract

Vibo Valentia’s S. Aloe quarter is an archaeological area which has three beautiful mosaic floors, dated between the centuries I BC and V AD. This work reports the results obtained on 22 glass and stone tesserae collected from the Nereid and Geometric mosaics during a recent restoration of the site. The analyses were carried out through a multi-analytical approach. The petrographic study of the stone tesserae was carried out using polarizing optical microscopy while the geochemical one was conducted using two micro-analytical techniques: the electron probe micro-analyzer with energy-dispersive X-ray spectrometry and a combination of laser ablation with inductively coupled plasma mass spectrometry for determining the major, minor, and trace element concentrations. The research highlights the use of different kinds of stones such as marble, volcanic, and sedimentary rocks. The glasses show the typical soda–lime–silica composition indicating the use of natron as a flux. The trace element concentrations prove the use of Pb-antimonates to create yellow glass. The bronze scrap was used to obtain the green color, while cobalt and copper were used to obtain different gradations of blue. These results confirm the high technological level reached by glassmakers in the Imperial Age, thus highlighting the importance of the S. Aloe archeological site.

Highlights

In the imperial period, private and public buildings were often decorated by mosaics, made of different kinds of materials, including pottery, stone, and glass.Mosaics were considered luxury goods and, they were not available for everyone to have at home, especially if the tesserae were made of rare and expensive materials such as marble and/or colored glass [1]
Eleven stone tesserae and ten glass tesserae were sampled from the Nereid mosaic
The results obtained on the stone and glass tesserae collected in the Nereid and Geometric mosaics results obtained on the stone and glass tesserae collected in the Nereid and Geometric in the archaeological area of S.area

Summary

Introduction

Private and public buildings were often decorated by mosaics, made of different kinds of materials, including pottery, stone, and glass.Mosaics were considered luxury goods and, they were not available for everyone to have at home, especially if the tesserae were made of rare and expensive materials such as marble and/or colored glass [1]. Because of the difficulties in finding this material during the Roman age, glass was considered as precious as a gem or a semi-precious stone used to make jewels. For this reason, its production was exclusively for aristocrats. The colorless Roman glass was essentially a mixture of three components: silica sand, lime, and natron—which is a soda rich mineral salt—used as a flux The abundance of this sodium carbonate in some evaporitic basins, like those of the Wadi El Natrun valley in Egypt, was, probably, the reason of the existence of primary glass-making centers in Egypt and in the Near East [13,14]

Objectives

Methods

Results

Discussion

Conclusion