Alessandra, Serges

Astrik, Gorghinian

Davit, Patrizia

Giacomo, Fiocco

Gulmini, Monica

Iaia, Cristiano

Leonie, Koch

LO GIUDICE, Alessandro

Marco, Ferretti

Marco, Malagodi

Re, Alessandro

Serena, Francone

Yatsuk, Oleh

English

Institutional Research Information System University of Turin

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 754511Preliminary spectroscopic results on glass circulation in the Iron Age Mediterranean from the perspective of Central Italy: the INGOT-EL project Oleh Yatsuk, Astrik Gorghinian, Giacomo Fiocco, Patrizia Davit, Serena Francone, Alessandra Serges, Leonie Koch, Alessandro Re, Alessandro Lo Giudice, Marco Malagodi, Cristiano Iaia and Monica GulminiICAS-EMME 3 congress, Nicosia, 14-18 of March 2022OBJECTIVES: 1. Establish cost-efficient, micro-invasive methodology for analyzing a large number of ancient glasses; 2. Give chemical characterization for glasses from Etruscan and Etruscanized sites; 3. Clarify the question of local glass production in Etruscan lands; 4. Reconstruct glass trade routes that were passing through the lands under Etruscan influence in the Iron Age.Stage 1:Study of typology and contextof glass objects.Photographic and microscopic imagingdocumentationStage2:non-invasive archaeometricstudy of objects.XRFFORSStage: 3micro-invasive analyses.SEM-EDSRamanXRDLA-ICP-MSThe INGOT-EL project:• 264 samples;• 14 archaeological sites;• 65 different graves;• 10-5 centuries BCE;2Archaeological sites:3Early Iron Age I Early Iron Age IIEarly Orientalising OrientalisingLate ArchaicType of the beads:VG58 VG60PG85 PG86800-675 BCEDistribution in time:4Description of the beads:Transversal section.Longitudinal section.5-9 mm1-3 mm3-6 mmUsually 3 eyes, sometimes 2 (when the bead is small and the eyes are big);050100150200250Volume without aperture, mm3Colour, translucency  and state of preservation vary slightly; PG44-47;5• How were these beads made?• Is there a single tradition in the production of these beads?• Does different state of preservation coincide with a different composition?• Where can be the place of production of these beads?Questions:Beads from Capena, Early Iron Age II, Villa Giulia museumBeads from Capena, Early Orientalising period, Museo delle Civita6Methods:Photography and microscopic imaging(all samples)FORS(all samples)Portable XRFunit 1(Part of VG samples)Cross section preparation and SEM-EDS analyses(3 samples)SEM-EDS analyses(low vacuum)(2 samples)Stage 1 Stage 2 Stage 355 samples within this study;most of the data are acquired within the museums;Portable XRFunit 2(Part of VG samples)Portable XRFunit 3(PG samples)7Cross calibration of XRF data from 3 different unitsData acquisition Creation of FP model for each XRF unitQuantification (Application of the FP model and calibration using standards)Correction of values using coefficients and QC of the dataArvedi laboratory unit –analyses in Museo delleCivita;INFN (Frascati) units – analyses in Villa Giulia;Main objective: to be able to compare the data from different sources within the same frame of reference. 8Forming technique: wound beads with inlaid coilsGroove of the detached coil; VG55. Protrusion near the apex; VG20.open end of the coil; round bubbles; VG35.Complete eye (inlaid coil); round bubbles; PG44.9Na2O MgO Al2O3 SiO2 SO3 K2O CaO TiO2 MnO FeO CuO Sb2O3PG110_1_blue 17.50 0.74 0.85 70.63 0.38 0.53 4.70 0.11 1.25 0.40 1.67 N.D.PG110_1_white 16.52 0.73 0.67 68.19 0.81 0.60 5.25 N.D. N.D. 0.30 N.D. 6.24 PG110_2 19.23 3.30 6.24 64.89 0.58 0.12 3.58 0.17 0.34 0.89 N.D. N.D.PG139 18.62 2.62 6.21 66.60 0.85 N.D. 4.00 0.06 0.18 0.74 N.D. N.D.Major components: SEM-EDS analyses** Samples PG156 and VG109 were analysed in the environmental mode, due to the surface alteration the values of alkali elements are significantly different.Cross sections PG110 (1), PG110 (2), PG139 demonstrate values of major components (coloured rectangles) that correspond to Soda-Lime-Silica glass. 10FORS data on flux:0102030405060708090470.671486.145501.589517.003532.386547.739563.062578.354593.616608.848624.05639.221654.362669.472Reflectance,%Wavelengthmaximum absorption at 535 nm - Soda rich flux*has to be taken with caution because of likely surface alteration (alkali leaching).XRF data on flux:00.20.40.60.811.21.41.6K,%Blue bases1100.0050.010.0150.020.0250.030.0350.040.045-1 0 1 2 3 4 5 6 7 8 9 10Sr, %Ca, %Network modifierR=0.61Ca values are comparable with IE soda lime glasses;Additional Ca is detected in the white parts of beads (green ellipsis) - probable influence of the colorant addition;SEM-EDS shows MgO values at – 2.62 - 3.3 % (for Co blue glasses);Single source of modifier is suggested;LOQ (estimation)**Here and later LOQ is estimated as 10X detection limit based on data provided by the producer of ELIO XRF unit.12Blue bases;            White decorations.Colors (FORS)Fe3+ - 375 nm;Fe3+ - Mn2+ complex – 425, 440 nm;Co2+ - 535, 600, 640 nm;Cu2+ - 775-835 nm (broad band);Fe2+ - NIR (broad band).020406080100120339.483378.751417.83456.717495.415533.923572.241610.37648.309686.059723.62760.992798.176835.171871.978908.597945.028981.2721017.328Reflectance,%WavelenghtBlue bases13020406080100120339.483378.751417.83456.717495.415533.923572.241610.37648.309686.059723.62760.992798.176835.171871.978908.597945.028981.2721017.328Reflectance, %WavelengthColors (FORS)Oxidation level variationFe3+ - Mn2+ Fe2+ variationCo2+ triplet Cu2+ Fe3+ - 375 nm;Fe3+ - Mn2+ complex – 425, 440 nm;Co2+ - 535, 600, 640 nm;Cu2+ - 775-835 nm (broad band);Fe2+ - NIR (broad band).14Colors (XRF; SEM-EDS)Significant increase of Sb in white decorations;Abundance of Sb rich inclusions (SEM-EDS) increase of Ca values is noted;PG110(1) cross section BSE image; white part (top) and blue part (bottom); point of the analysis in the white part shows 10.97 % of Sb2O3;012345678910%Ca SbCa/Sb white = 5.2;Ca/Sb blue = 11.7;Ca white/ Ca blue = 1.69.1500.020.040.060.080.10.120.140 0.05 0.1 0.15 0.2 0.25Ni, %Co, %LOQ (estimation)LOQ (estimation)R=0.85Suggestions of provenanceCo/Ni binary plot includes data of XRF Unit 1 and Unit 2 on blue bases (XRF Unit 3 values have great relative errors)PG73-74PG92PG15100.0050.010.0150.020.0250.030.0350.040.0450.050 0.05 0.1 0.15 0.2 0.25 0.3 0.35Zr, %Ti, %LOQ (estimation)LOQ (estimation)Blue bases;            White decorations.16PG138PG107PG109PG110PG111VG106PG73-74PG79PG4600.20.40.60.811.20 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8Cu, %Mn, %LOQ (estimation)LOQ (estimation)PG150PG86PG46PG138PG109 PG110PG111PG112VG75VG73VG74VG106VG108VG109-111VG112VG6000.511.522.50 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8Fe, %Mn, %LOQ (estimation)Blue bases;            White decorations.17Notes to keep in mind:Instead of conclusionHow these beads were made?• Soda-lime-silica glass; • Possible recycled glass use; • Wound beads with coil eye decoration; Variety of sizes without one or several standards.Is there a single tradition in the production of these beads? • The colorants used are the same so is the aspiration to similar appearance (with exceptions); Where can the place of production of these beads be?• Same place of production of raw glass is likely, some raw materials source is probably Egypt; • Several outliers have to be kept in mind. 18Future work:Instead of conclusion• Refining of XRF data;• Comparing with other groups of samples; • Introducing new data of the stage 3 into discussion including LA-ICP-MS data;• Cross validation of data;• Checking the veracity of the preliminary conclusions.19

Preliminary spectroscopic results on glass circulation in the Iron Age Mediterranean from the perspective of Central Italy: the INGOT-EL project

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Preliminary spectroscopic results on glass circulation in the Iron Age Mediterranean from the perspective of Central Italy: the INGOT-EL project

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