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