THE SECTILIA PANELS OF FARAGOLA (ASCOLI SATRIANO, SOUTHERN ITALY): A MULTI‐ANALYTICAL STUDY OF THE RED, ORANGE AND YELLOW GLASS SLABS*

Abstract

SEM–EDS, EMPA, ICP–MS and ICP–OES were applied to the study of three sectilia panels made of red, orange and yellow glass slabs. In order to determine the chemical state of Cu, XAS was also performed. The results indicate that, with the exception of the red samples, all slabs were made by mixing a siliceous sand with natron. The red slabs show significant compositional differences with respect to K2O and MgO contents, probably linked to the use of plant ashes as a source of alkali. The red, orange and yellow slabs are coloured by metallic copper, cuprite and Pb antimonates, respectively. The comparison between the chemical composition of the Faragola samples and several glass reference groups did not provide conclusive evidence of provenance.

Late Antique Glass Vessels and Production Indicators from the Town of Herdonia (Foggia, Italy): New Data on Cao‐Rich/Weak HIMT Glass

“…Beyond the chronological distance of these references, the area indicated for comparison ‐ lies mostly between Syria and Egypt. Comparing the composition of slab 38 with the glass slabs and tesserae found at the nearby site of Faragola (Santagostino Barbone et al ; Gliozzo et al 2010, 2012), it is possible to notice that the K 2 O and Fe 2 O 3 values are similar to those of the red and orange slabs, but considering the other components, the best match is with the red tessera (FT 2)—which, however, is a natron‐based glass.…”

“…The archaeometric research on Apulian glass started with the investigation of tesserae and slabs found at Faragola (about 15 km from Herdonia : see Santagostino Barbone et al ; Gliozzo et al , ). Those projects were followed by seminal research on Herdonia glass (Turchiano ; Santagostino Barbone et al ).…”

Late antique glass distribution and consumption in Cyprus: a chemical study

“…Although natron based glasses constitute the vast majority of Roman and post-Roman objects until the 8th century AD, there are evidences that soda plant ash was already used for specific productions. Glassmakers used soda plant ash for copper coloured emerald green vessels, typical of the 1ste3rd century AD (Jackson et al, 2009;Gallo et al, 2013;Rosenow and Rehren, 2014), some contemporary black glass (Cosyns, 2011) and red copper coloured Roman and Byzantine mosaic tesserae (Freestone et al, 1990;Brun et al, 1991;Shugar, 2000;Santagostino Barbone et al, 2008). A type of plant ash based blue-green glass was found in Wadi Natrun (Egypt), although it seems that it was not traded outside this region (Picon et al, 2008).…”

A Study of Glass Tesserae From Mosaics in the Monasteries of Daphni and Hosios Loukas (Greece)

“…2002; Arletti et al. 2006a, b; Santagostino Barbone et al. 2008) show that the addition of Pb or Fe as reducing agents was a common practice in the production of ancient glass to induce Cu reduction to metallic Cu or CuO.…”