Introduction Mosaic tesserae are primarily made out of stones,
ceramics or glass. The tesserae being analyzed were
made of glass. Glass samples can be analyzed via X-
Ray Fluorescence (XRF), Raman Spectroscopy, and
Fourier Transform Infrared Spectroscopy (FTIR). XRF
spectrometry is a common instrument for analyzing
glass samples because it allows for more efficient
fieldwork, sufficient detection limits and is non-
destructive. XRF instruments can detect from Ca to Pb
in SiO2. The main coloring agents in the glass
tesserae analyzed were found to be Fe, Cu, Mn, and
Co. Energy-dispersive XRF spectrometry was used to
analyze the tesserae samples.
Instrumentation •Bruker Tracer III-V, yellow filter, 8 A, 40keV
•Bruker Tracer III-SD
•with vacuum pump, no filter, 25 A, 15 keV
•With out vacuum pump, yellow filter, 11.7 A,
40keV
References 1.Perdomo, M. A. F. M. S. T. F., Mosaics in Mexico. Artes de Mexico: Mexico City, 2006.
2.Fiori, C.; Rocuzzi-Fiorentini, I.; Vandini, M., Colors and stories of the Italian mosaics. Monogr. Mater.
Soc. 2001, 5 (Art of Ceramics), 149-172.
3.Janssens, K. Modern Methods for Analysing Archaeological and Historical Glass. John Wiley & Sons Ltd:
United Kingdom, 2013; Vol. 1, p 309.
4.James, L., Byzantine glass mosaic tesserae: some material
considerations. Byzantine and Modern Greek Studies 2006, 30 (1), 29-47.
5.Silvestri, A.; Tonietto, S.; D’Acapito, F.; Molin, G., The role of copper on colour of palaeo-Christian glass
mosaic tesserae: An XAS study. Journal of Cultural Heritage 2012, 13 (2), 137-144.
6.Douglas A. Skoog, F. J. H., Stanley R. Crouch, Instrumental Analysis. Brooks/Cole: Canada, 2007.
Acknowledgements I would like to thank Dr. Mary Kate Donais for
all of her guidance throughout this project.
Results
Conclusions •Through the XRF analyses and principal
component analyses (PCA), some of the
key elements within the mosaic tesserae
were identified.
•The PCA of all the Dark Blue tesserae
showed that the samples varied only in
relative elemental concentration.
•The PCA and overlaying plot of the
varying Dark Blue homogeneity study
tesserae showed that the Dark blue
tesserae are not homogeneous.
Method The tesserae were separated by visual inspection
and analyzed via XRF. Spectrometry. For some
tesserae all six sides were analyzed under
vacuum conditions. Also for each color one whole
tesserae was analyzed and then the tesserae was
crushed and the crushed tesserae was analyzed.
All Tesserae Scores/Loadings Plots
Fe
Cu Sb
Ca
Mn
Fe
Cu Sb
Ca
Mn
Dark Blue Homogeneity
Scores/Loadings Plots
Fe
Cu
Sb
Pb
Dark Blue Scores/Loadings Plots
0
0.2
0.4
0.6
0.8
1
1.2
0.0
19
0.9
94
1.9
69
2.9
44
3.9
19
4.8
94
5.8
69
6.8
44
7.8
19
8.7
94
9.7
69
10
.74
4
11
.71
9
12
.69
4
13
.66
9
14
.64
4
15
.61
9
16
.59
4
17
.56
9
18
.54
4
19
.51
9
20
.49
4
21
.46
9
22
.44
4
23
.41
9
24
.39
4
25
.36
9
26
.34
4
27
.31
9
28
.29
4
29
.26
9
30
.24
4
31
.21
9
32
.19
4
33
.16
9
34
.14
4
35
.11
9
36
.09
4
37
.06
9
38
.04
4
39
.01
9
Inte
ns
ity
X-Ray Energy (keV)
Overlap of Dark Blue Tesserae Whole and then Crushed
Dark Blue B crushed
Dark Blue B whole
Dark Blue Crushed
Dark Blue F crushed
Dark Blue F whole
