Micro Raman spectroscopy (MRS) and energy dispersive x-ray microfluorescence (μEDXRF) analysis of...

Research Article

Received: 13 December 2011 Revised: 5 March 2012 Accepted: 12 March 2012 Published online in Wiley Online Library

(wileyonlinelibrary.com) DOI 10.1002/jrs.4080

Micro Raman spectroscopy (MRS) and energydispersive x-ray microfluorescence (mEDXRF)analysis of pigments in the Iberian cemetery ofTutugi (from the fourth to the third century BC,Galera, Granada, Spain)†

Alberto Sánchez,a* José Tuñón,a Manuel Montejob and David Parrasc

Recent archaeological research on the Iberian cemetery of Tutugi (from fourth to third century BC), in the administrative termof Galera (Granada, Spain), has granted access to a range of materials revealing major features of Iberian culture. The onlyinformation available on pigments in the Iberian culture refers to domestic ceramic and the inside covering of burials. Thispaper expands on the previous discussion by incorporating pigment studies of the decoration of highly symbolic ceramicvessels, a funerary urn and a glass paste vessel of three burials of the cemetery of Tutugi.

Regarding the method, the pigment study relied on the mineralogical and elemental analysis using non-destructivespectroscopic techniques such as micro Raman spectroscopy (MRS) and Energy Dispersive X-Ray Microfluorescence(mEDXRF). These studies are used more and more frequently for research on archaeological items for their advantagesover other techniques.

The results obtained indicate the use of hematite, cinnabar and gypsum in the decoration of ceramic vessels. The pigmentsused for the urn were made with hematite, gypsum and amorphous carbon. Naples yellow and Egyptian blue were used aspigments in the fragment of glass paste vessel.

Overall, joint use of MRS and mEDXRF provides highly valuable data on the processes used for pigment-making, on the useof certain minerals that are highly symbolic among Iberians, such as cinnabar, and provides new evidence for the preservationof archaeological items retrieved from the burial site. Copyright © 2012 John Wiley & Sons, Ltd.

Keywords: archaeology; pigments; micro Raman spectroscopy; X-ray fluorescence; Iberians

* Correspondence to: Alberto Sánchez, Andalusian Centre for Iberian Archaeology,University of Jaén, Jaén, Spain.E-mail: [email protected]

† This article is part of the Journal of Raman Spectroscopy special issue entitled“Raman spectroscopy in art and archaeology” edited by Juan Manuel MadariagaMota and Danilo Bersani.

a Andalusian Centre for Iberian Archaeology, University of Jaén, Jaén, Spain

b Department of Physical and Analytical Chemistry, University of Jaén, Jaén, Spain

c Archaeological Heritage of Jaén Research Unit, University of Jaén, Jaén, Spain

IntroductionThe Iberians are known to have been the most advanced culturein the Iberian Peninsula during the Iron Age. Geographically, theIberian culture spread over the south, east and north of theIberian Peninsula, as well as over the southeast of present-dayFrance. Therefore, they were a clearly Mediterranean culture.

The Iberian world developed from the end of the seventhcentury BC. and reached its zenith during the fifth to the third cen-tury BC. After the Second Punic War, and as a result of the Romancontrol of the Iberian Peninsula, a slow process of romanizationstarted that ended in the first century BC. Throughout that period,the Iberians were under the influence of Phoenician, Greek andCarthaginian settlements in the Iberian peninsula. The close eco-nomic and cultural relations between the latter cultures and theIberians contributed to the Iberian world’s particular profile.[1,2]

The study samples were obtained from the cemetery of Tutugi,which sets in the cultural framework described earlier. It is one ofthe major Iberian cremation burials both for its form and for itsrelevance. The size and the distribution of the burial moundswithin the burial place and the grave goods retrieved are evi-dence of the hierarchical structure of the Iberian society, as wellas of the existence of complex funerary rituals.

The cemetery of Tutugi lies in Galera, in the province of Granada(Spain). Looted several times since its discovery in 1914, it was

J. Raman Spectrosc. (2012)

recently surveyed in 2000 and 2009 for musealization and dissem-ination purposes. The cemetery consists of 140 mounds datingback to the period between the fourth and the third century BC

and is distributed over a surface of ca. 40ha. The 2000 and 2009campaigns surveyed 15 mounds again, all featuring entrance corri-dors and quadrangular chambers covered by an earthen mound tohouse the cremated remains and the burial goods.[3–5]

Research on pigments used by the Iberians for the decorationof a number of items (pottery, wall coverings, sculptures andglass paste) based on physico-chemical techniques is relativelyrecent. This field stands out for the use of spectroscopic

Copyright © 2012 John Wiley & Sons, Ltd.

A. Sánchez et al.

techniques, especially in view of the relevance of the targetculture and the wide range of materials used by Iberians.Micro Raman spectroscopy (MRS) stands out as a highly effec-

tive technique that is especially appropriate for the analysis ofarchaeological samples. This is mainly because it is a non-destructive technique and does not need any sample prepara-tion. Its high spatial resolution is also ideal for research on smallpigment grains retrieved from a heterogeneous sample or, ingeneral, where samples are small.[6–9] Finally, MRS is a versatiletechnique that can be used on items of several sizes and on solidand powder samples without sample preparation.[10,11]

Micro Raman spectroscopy’s major limitation is that fluores-cence may hinder the identification of the characteristic bandsof some minerals according to the matrix where they occur.[9]

Energy dispersive X-ray microfluorescence (mEDXRF) may thuscomplement the data obtained by MRS for samples where MRSmay yield inconclusive results or be inappropriate for the pro-perties of the material under study.Micro Raman spectroscopy-based research on pigments used

in Iberian items has contributed to a better knowledge of decora-tion preferences, decoration stages and even the origin of thematerials used. Ceramics and coverings have been studied sys-tematically using this technique. The results obtained allowedfor identification of the minerals used for a number of pigments:red, white, black and blue.[12–15] Specifically, the pigments usedin the plastering of the tombs, and the remains of a sculptureof the cemetery of Tutugi are the subject of previous studies.[8,12]

Research on Iberian sculptures also identified the red, white,black and blue pigments of the two of the main Iberiansculptures, the Lady of Baza and the Lady of Elche, even if inthese cases only mEDXRF and scanning electron microscopy(SEM))[16–18] were used for the elemental analysis of the samples.Still, MRS has been applied on the pigments of a small number ofsites. Further materials and items from a range of contextsshould be added if the aim is to identify, with accuracy, this fieldin the research of the Iberian culture.Considering the previous discussion, this paper addresses

several objectives. Firstly, it is the first paper to analyse ceramicvessels of a distinct typology and retrieved from a burial site, spe-cifically, from the cemetery of Tutugi. To the best of our knowl-edge, MRS has not been applied on Iberian ceramics other thanfrom domestic contexts. Secondly, the paper applies this tech-nique on items for which this approach is a novelty, specificallya funerary urn and a fragment of glass paste. Finally, it enlargesthe body of data needed in restoration and musealization, bothof the archaeological items researched and of the cemetery fromwhich they were retrieved.The method used is based on systematic MRS and mEDXRF

analysis. The latter is intended to complete the results obtainedby MRS wherever such results are inconclusive or where theMRS results may have been limited by the nature of the materialsunder study.

Experimental details

Samples

The materials retrieved from the archaeological site and understudy in this paper were selected according to their archaeologi-cal relevance and to their decoration: a bowl and two ceramicfragments, two fragments of a funerary urn made of stone anda fragment of glass paste (Fig. 1, Table 1).

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The ceramic fragments stand out among the pottery found inthe burial site for their decoration. The funerary urn, which thetwo fragments studied belong to, was retrieved from moundno. 76 during the 1918 campaign. They belong to the series ofitems made of stone recorded in the burial site. The fragmentof glass paste most likely comes from a small vessel, which mayultimately be Phoenician in origin. It is one of the most remark-able sample types in the burial site.

Micro Raman spectroscopy

The samples were analysed using a Renishaw ‘in via’ ReflexSpectrometer coupled with a confocal Leica dissecting microscopy(DM) light microscopy (LM) microscope (CICT, University of Jaén),equipped with an argon ion laser (lexc = 514.5nm, 25mW) and adiode laser (lexc = 785nm, 300mW), and a Peltier-cooled charge-coupled device detector, calibrated to the 520.5 cm�1 line of silicon.The maximum laser output power was eventually reduced usingneutral density filters. The spectra were acquired using the50� objective, in the 100–2000 cm�1 region, with spectral reso-lution of ca. 2 cm�1 (1800 lines/mm grating) and ca. 1 cm�1

(1200 lines/mm grating). Acquisition time was set between 10and 60 s per accumulation, and the maximum number of accu-mulations was 15. The laser spot size available is in the 1–300mmrange depending on the wavelength and objective used.

Energy dispersive X-ray fluorescence spectroscopy

Energy dispersive analysis of X-rays (model Eagle III) fluorescencespectrometer was used for this paper (CITI, University of Sevilla).This spectrometer is equipped with a microfocus X-ray tube withan Rh anode, a polycapillary lens for X-ray focussing and an80mm2 energy dispersive Si-(Li) detector. The sample chamberincorporates an XYZ motorised stage for sample positioning. Ahigh resolution microscope is used to position the sample onthe desired distance from the polycapillary. To increase the sensi-tivity of the low Z elements, the sample chamber can be broughtunder vacuum. The device is calibrated using the Ka peaks ofaluminium (1.48 keV) and copper (8.04 keV) as measured in a50% Al–Cu standard. For the analysis of the samples, a spot sizeof 300mm was chosen at an operating X-ray tube voltage of40 kV. The tube current was adapted for each sample in orderto optimise the detection of X-rays. Intensity range was between600 and 950 mA.

Results and discussion

The data collected yield a rather accurate description of therange of materials used for the decoration of the samplesretrieved from the cemetery of Tutugi. The results also confirmthe appropriateness of a combined MRS and mEDXRF analysisfor higher accuracy in the identification of pigments.

Ceramic materials

The bowl and the other two ceramic fragments under study eachshow a characteristic decoration and yield data of the pigmentsused for the ceramic vessels.

Sample 11023

Sample 11023 belongs to a well-known Iberian pattern: a bowlwith red decoration both on the inside and the outside. The

2 John Wiley & Sons, Ltd. J. Raman Spectrosc. (2012)

Figure 1. Archaeological material studied in this work. (a) ceramic bowl 11023; (b) ceramic fragments 34004-1 and 34004-2; (c) fragment of burial urn76038-1; (d) fragment of burial urn 76044; and (e) glass paste 34010.

Table 1. Archaeological material studied in this work and description

Type Sample Description

Ceramic 11023 Bowl decorated with red

bands inside and outside

34004-1, 34004-2 Fragments of indeterminate

shape with red decoration

on white background

Stone 76038-1, 76044 Fragments of a funerary urn

with white, red and black

vegetal patterns and lines

Glass paste 34010 Fragment of indeterminate

shape decorated with blue

and yellow zigzag decoration

MRS and mEDXRF analysis of pigments

J. Raman Spectrosc. (2012) Copyright © 2012 John Wiley

Raman spectrum for the coloured area shows a profile thatallows one to conclude that the mineral used for the redpigment is hematite (Fe2O3), whose vibrational spectrum showsits most significant bands near the wavenumbers observed[12,13,19]

(Fig. 2, Table 2).The mEDXRF analysis of the decoration yielded results that are

compatible with the previous and which provide additionaldetails (Table 3). Specifically, the high proportion of Al and Sifound suggests that the pigment was made adding hematite toa base high in clay content.

Samples 34004-1 and 34004-2

These samples are similar ceramic fragments, although it cannotbe stated that they belonged to the same vessel. Both show reddecoration on a white background.

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Figure 2. Ceramic bowl 11023. Red decoration. Raman spectrum ofhematite: 50� objective, five accumulations of 10 s, 785 nm diode laser,15mW, 300 s bleaching, and 150–1800 cm�1.

A. Sánchez et al.

The Raman spectra of the coloured areas show a complex pro-file where three different minerals can be detected (Fig. 3). Thepeaks at 254 and 342 cm�1 indicate the occurrence of cinnabar(a-HgS), whose Raman spectrum has three intense vibrationbands in those wavenumbers.[20] The bands at 292, 411, 492and 611 cm�1 indicate the occurrence of hematite, whose Ramanspectrum also shows intense bands in those positions.[12,14,19,21]

Finally, the band at 1011 cm�1 reveals the occurrence of gypsum(CaSO4�2H2O), whose Raman spectrum has its most intenseband near that wavenumber.[20] Gypsum must have been themain component (along with dolomite in the case of sample34004-2, as shown in Table 2) in the white covering of theceramic vessel on which red decoration was applied (Fig. 4).The results obtained by mEDXRF complement the aforemen-

tioned discussion. Thus, detection of both Fe and Hg indicates

Table 2. Observed Raman bands and pigment identification

Sample Colour W

11023 Red 223, 246, 2

34004-1 White 416, 493, 6

Red 254, 342

292, 411, 4

1011

34004-2 White 416, 491, 6

1096

Red 252, 341

223, 291, 4

1008

76044 White 414, 493, 6

Black 1345, 1595

Red 225, 244, 2

1008

76038-1 White 413, 495, 6

Black 1335, 1586

1010

Red 225, 246, 2

1010, 1137

1098

34010 Yellow 142, 215, 3

724, 757


that a mixture of minerals containing both elements was used(even if the proportion Hg/Fe varies slightly according to thearea). However, all the mEDXRF analyses carried out in sample34004-1 presented a Fe/Hg ratio higher than one, whereas thisratio is lower than one in analysed areas in sample 34004-2(Table 3). This feature may indicate that each fragment belongsto a different vessel or, alternatively, that different pigments wereapplied on the same vessel.

The occurrence of gypsum and dolomite in the white coveringis confirmed by the high percentages of Ca, S and Mg detected.Besides, the use of dolomite in the elaboration of the red pig-ments in samples 34004-1 and 34004-2 cannot be discarded,considering the high proportions of Mg in the red areas of thesamples (Table 3).

Remarkably, the use of cinnabar is a major indication oftechnological achievement in the manufacturing of the vessel.It means that decoration took place after firing because, attemperatures above 200 �C, cinnabar is reduced and the mercuryof the mineral evaporates at 357 �C.[22]

Stone items

Samples 76038-1 and 76044 were collected from a stone burialurn. Both samples show white-coloured, red-coloured andblack-coloured areas (Fig. 1). For easier reading, and as the resultsobtained from both samples are similar, the following refers tosample 76044 but applies to sample 76038-1. The Raman bandsrecorded are shown in Table 2, and the results obtained bymEDXRF are shown in Table 3.

The Raman spectra obtained from the white, black and redareas show the typical vibration bands for gypsum, amorphouscarbon and hematite, respectively (Fig. 5).[23,24] The vegetal originof carbon is confirmed by the lack of a band at 960 cm�1 (whichsignals the occurrence of apatite and is linked to bone or ivory) aswell as by the low phosphorous proportion detected in the

avenumber/cm�1 Identification

91, 409, 494, 611, 659, 1318 Hematite

20, 671, 1010, 1138 Gypsum

Cinnabar

92, 611, 1328 Hematite

Gypsum

15, 670, 1009, 1136 Gypsum

Dolomite

Cinnabar

09, 491, 611 Hematite

Gypsum

22, 672, 1010, 1119, 1138 Gypsum

Amorphous carbon

91, 409, 494, 611, 1316 Hematite

Gypsum

20, 673, 1009, 1137 Gypsum

Amorphous carbon

Gypsum

91, 410, 494, 612 Hematite

Gypsum

Dolomite

02, 335, 387, 456, 512, 639 Naples yellow

Antimony oxide (V)


Table

3.En

ergydispersive

X-ray

microfluorescen

ceresults

Sample

Area

Com

position(At%

)

Na 2O

MgO

Al 2O3

SiO2

P 2O5

SO3

Cl 2O

K2O

CaO

Sc2O3

TiO2

V2O5

Cr 2O3

MnO

Fe2O3

CoO

Ni 2O3

CuO

SrO

ZrO

2Pd

OSb

2O3HgO2

SnO2

PbO2

Mo2O3

1102

3Re

d1

<LO

D12

.85

9.68

56.17

0.19

2.81

1.41

3.56

9.69

0.03

0.61

0.02

0.01

0.01

2.76

0.06

<LO

D<LO

D0.04

0.02

0.06

0.02

<LO

D<LO

D<LO

D<LO

D

Red2

0.98

13.26

8.68

44.43

0.50

6.33

1.85

1.86

8.81

0.03

0.60

0.01

0.01

0.10

12.03

0.24

<LO

D0.03

0.06

0.04

0.11

0.02

<LO

D<LO

D<LO

D<LO

D

Red3

0.27

12.87

9.15

54.65

0.56

3.45

1.65

3.82

9.33

0.04

0.60

0.01

0.01

0.04

3.33

0.08

<LO

D0.02

0.04

0.02

0.05

<LO

D<LO

D<LO

D<LO

D<LO

D

Red4

<LO

D12

.31

7.53

50.80

0.12

5.94

1.57

1.32

10.43

0.05

0.52

<LO

D0.01

0.08

8.96

0.14

<LO

D0.03

0.07

<LO

D0.08

0.01

0.02

<LO

D<LO

D<LO

D

3400

4-1

Red1

0.28

14.82

3.20

5.96

1.02

34.25

0.92

0.35

37.86

0.13

0.07

<LO

D<LO

D0.04

0.87

0.03

0.01

0.01

0.05

<LO

D0.05

0.01

0.08

<LO

D<LO

D<LO

D

Red2

<LO

D12

.43

1.77

4.72

1.14

37.29

0.88

0.21

40.23

0.23

0.04

<LO

D<LO

D0.05

0.71

0.03

0.01

0.01

0.05

<LO

D0.06

0.01

0.12

<LO

D<LO

D<LO

D

Red3

1.19

15.87

2.63

6.09

1.11

33.06

0.92

0.22

37.17

0.21

0.05

<LO

D0.01

0.05

1.10

0.04

0.01

<LO

D0.05

<LO

D0.06

<LO

D0.17

<LO

D<LO

D<LO

D

Red4

<LO

D14

.85

2.99

6.49

1.08

35.54

0.85

0.21

34.15

0.17

2.16

<LO

D<LO

D0.07

1.11

0.06

0.01

<LO

D0.04

<LO

D0.05

0.02

0.14

<LO

D<LO

D<LO

D

White

0.86

4.45

1.11

1.28

1.21

49.53

0.68

0.13

40.01

0.24

0.07

<LO

D0.01

0.06

0.24

0.02

0.01

<LO

D0.04

<LO

D0.04

0.02

<LO

D<LO

D<LO

D<LO

D

3400

4-2

Red1

<LO

D10

.01

2.45

18.60

1.56

36.04

0.52

0.20

29.48

0.21

0.03

<LO

D<LO

D0.04

0.20

<LO

D0.01

<LO

D0.08

<LO

D0.05

0.02

0.50

<LO

D<LO

D<LO

D

Red2

0.48

6.14

1.99

18.15

1.60

40.33

0.52

0.22

29.45

0.20

0.05

<LO

D0.01

0.04

0.13

0.01

<LO

D<LO

D0.07

<LO

D0.05

<LO

D0.56

<LO

D<LO

D<LO

D

White

0.51

2.86

0.51

2.64

1.27

49.14

0.57

0.14

41.72

0.27

0.05

<LO

D<LO

D0.07

0.10

0.01

0.01

<LO

D0.07

<LO

D0.05

0.01

0.01

<LO

D<LO

D<LO

D

7604

4Re

d1

19.23

<LO

D<LO

D4.35

<LO

D8.47

6.45

0.84

34.38

0.29

0.51

<LO

D<LO

D<LO

D23

.52

0.21

<LO

D0.01

0.24

0.01

1.37

0.11

<LO

D<LO

D<LO

D<LO

D

Red2

23.56

2.70

<LO

D4.42

<LO

D7.97

5.55

0.85

32.79

0.27

0.44

<LO

D0.02

0.02

19.70

0.10

<LO

D0.03

0.42

0.02

1.08

0.07

<LO

D<LO

D<LO

D<LO

D

White

3.61

2.14

0.65

4.67

0.88

28.93<LO

D0.24

57.21

0.57

<LO

D<LO

D0.01

0.05

0.14

<LO

D0.01

0.01

0.33

0.02

0.44

0.06

<LO

D<LO

D<LO

D<LO

D

Black

8.50

1.21

<LO

D6.19

0.17

11.51

3.35

1.08

62.55

0.47

0.65

<LO

D0.04

0.07

2.16

0.05

0.01

0.06

0.73

0.03

1.02

0.14

<LO

D<LO

D<LO

D<LO

D

3401

0Ye

llow

9.48

0.18

2.45

53.68<LO

D17

.94<LO

D<LO

D5.74

<LO

D0.05

<LO

D0.02

0.01

1.80

0.02

<LO

D0.08

<LO

D<LO

D<LO

D1.01

<LO

D<LO

D7.52

0.01

Blue1

7.09

0.18

2.19

78.17<LO

D0.99

<LO

D<LO

D10

.04<LO

D0.06

<LO

D0.01

0.01

0.14

0.01

<LO

D1.02

<LO

D<LO

D<LO

D0.05

<LO

D<LO

D0.04

<LO

D

Blue2

5.73

<LO

D2.10

79.65<LO

D0.72

<LO

D<LO

D10

.18<LO

D0.05

<LO

D0.01

0.01

0.17

0.01

<LO

D1.10

<LO

D<LO

D<LO

D0.22

<LO

D<LO

D0.05

<LO

D

<LO

D,u

nder

limitofdetection.


J. Raman Spectrosc. (2012) Copyright © 2012 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/jrs

Figure 3. Ceramic fragment 34004-1. Red decoration. Raman spectrumof cinnabar, hematite and gypsum: 50� objective, five accumulations of10 s, 785 nm diode laser, 15mW, 300 s bleaching, and 200–1600 cm�1.

Figure 4. Ceramic fragment 34004-1. White decoration. Raman spec-trum of gypsum: 50� objective, five accumulations of 10 s, 785 nm diodelaser, 30mW, and 200–1600 cm�1.

Figure 5. Funerary urn 76044. Red decoration. Raman spectrum ofhematite: 50� objective, ten accumulations of 10 s, 785 nm diode laser,15mW, and 200–2000 cm�1. White decoration. Raman spectrum ofgypsum: 50� objective, ten accumulations of 10 s, 785 nm diode laser,3mW, and 200–2000 cm�1. Black decoration. Raman spectrum ofamorphous carbon: 50� objective, ten accumulations of 10 s, 785 nmdiode laser, 3mW, and 200–2000 cm�1.

A. Sánchez et al.

subsequent mEDXRF analysis. The band at 1008 cm�1 in thespectrum of the red area indicates the occurrence of gypsum,probably as the background matter on which decoration wasapplied.The mEDXRF analysis of sample 76 044 confirms the results

obtained by MRS as regards the composition of the red pigment,i.e. iron ore is one of the main components. Still, this sampleshows a lower proportion of Al (<LOD) and Si (4.35 and 4.42 at%) and a higher proportion of Fe (23.52 and 19.70 at%) than inthe results obtained for sample 11023 by using the same tech-nique. Thus, it can be concluded that both pigments were madeusing different amounts of hematite, and that the higher amountof ferrous mineral occurs in the pigment used in sample 76044(Table 3).

Glass paste

Fragment 34010 is made of glass paste (Fig. 1) and has bandsmainly of two colours: yellow and blue.As shown in Table 2, the Raman spectrum of the yellow area

yields the typical bands of the pigment known as Naples yellow(Pb2Sb2O7)

[24–27] (Fig. 6). This is an artificial pigment that has


been used often since the Egyptians used it for the decorationof faience, in the second millennium.[28]

Two more bands occur next to the Naples yellow bands, specif-ically at 724 and 757 cm�1. Both can be attributed to antimonyoxide (V), Sb2O5,

[29] a reactive used for the synthesis of Naplesyellow and that may not have been entirely consumed duringthe reaction that yields the pigment.[30]


Figure 6. Glass paste bowl 34010. Yellow decoration. Raman spectrumof Naples yellow: 50� objective, ten accumulations of 10 s, 514.5 nm Ar+

laser, 12mW, 100 s bleaching, and 150–1800 cm�1.


The fluorescence that usually affects the analysis of glasspaste[6,8] hindered the MRS identification of the pigment usedfor light blue. Therefore, mEDXRF was used for the analysis ofthis area.

The results yield a chemical profile where copper, calcium andsilicon prevail (Fig. 7, Table 3). This suggests that the pigmentused for the light blue band must be Egyptian blue, which is wellknown and whose earliest known use dates back to the Egyptiansof the third millennium.[20,31]

This pigment was usually synthesised from a mixture ofcalcareous rocks, quartz sand, copper ore and a sodium fuser ata temperature between 850 and 1100 �C. The result is a hetero-geneous matter made mainly of a crystalline phase and ofan amorphous phase. The crystalline phase consists of bluecrystals of cuprorivaite (CaCuSi4O10) and colourless crystals ofquartz (SiO2).

[32]

Conclusions

The aforementioned results allow one to obtain, for the first timein the context of the Iberian culture, a comprehensive and diver-sified account of the minerals used for the pigments contained ina range of materials.

Unlike former research offering partial and occasional resultson the chemical and mineral composition of ceramic and sculp-ture materials (the Lady of Baza, the Lady of Elche and ceramicsretrieved from Puente Tablas and La Vispesa),[15,17,18] this paperdetails a range of materials used in a homogenous context forthree types of items: ceramic, stone and glass paste. Severalpatterns and preferences have been found to govern the deco-ration of archaeological items.

The use of hematite for the red pigment of vessel 11023 is inaccordance with the usual procedure for ceramic decoration ingeneral, and of Iberian pottery in particular, where it was also afrequent decoration resource.[13]

Use of red pigment obtained from a mixture of cinnabar andhematite, as recorded for fragments 34004-1 and 34004-2 is lesscommon. Therefore, this paper presents the first MRS-basedrecord of the use of cinnabar in Iberian items, because in caseslike the Lady of Baza and the Lady of Elche. Hg was recorded onlyby use of mEDXRF and SEM.

J. Raman Spectrosc. (2012) Copyright © 2012 John Wiley

The use of cinnabar seems to have clear symbolic, aesthetic oreconomic implications: a rarer mineral than iron ore and a highlyvalued one in decoration, cinnabar is known to have been exca-vated since the Neolithic and to have been used for pigments ina number of contexts and periods ranging from Pompeii, thepalace of king Herod in Jericho, the Mayans or the ancientChinese culture.[33–36] Exclusive and rare, it is easy to understandthat it may have been mixed with hematite.[37]

Cinnabar is not the most common pigment. Its occurrenceconfers the item an added significance, especially consideringthat this mineral was used for both the decoration of the afore-mentioned Lady of Baza and Lady of Elche.[17] It should be notedthat cinnabar was probably less difficult to obtain than it usuallywas as a result of the natural cinnabar outcrop in Cerro Quintana,in the nearby Sierra de Baza (ca. 40 kms away). Still, this outcropcannot have supplied enough material, as it occurs mixed withhematite. Alternatively, the mixture of minerals may haveresponded to the aesthetic need to obtain a particular shade ofred for decoration. Finally, the ferrous mineral may have had acompletely natural origin, if it occurred in the cinnabar outcrop.

The pigments of the funerary urn show a clear pattern and usegypsum, amorphous carbon and hematite for white, black andred, respectively. The occurrence of black in a funerary urn andits identification as vegetal amorphous carbon is in line withthe previous research on the Iberian culture, where black wasmade from burned vegetable matter. Bone, ivory and othermineral pigments, such as pyrolusite, can thus be discarded forthis purpose.

The mEDXRF analysis of the relative proportion of iron ore inthe red pigment of the funerary urn and in the decoration ofceramic 11023 yielded a distinct manufacture procedure. Thered pigment of the urn used a concentration of hematite that ismuch higher than the one found in the ceramic 11023, wherethe base of the pigment is high in clay content.

Finally, the glass paste shows two different pigments that werewell known in the Mediterranean: Naples yellow for yellow andEgyptian blue for blue. Both are rare in the material culture ofthe Iberians, especially the former. Like cinnabar, the latter wasused mainly for symbolic, ritual and funerary items and contexts.

Acknowledgements

We would like to thank the CICT of the University of Jaén forthe use of MRS equipment. We would also like to thank the staffof the CITI at the University of Seville for their advice on themEDXRF analysis. Finally, we would like to thank María OlivaRodríguez Ariza, the head of the team that excavated thecemetery of Tutugi. This work was supported by funds fromthe Andalusian Centre for Iberian Archaeology, the AndalusianGovernment, FEDER Funds and by the research projectArqueologia y Quimica: La cultura de los Iberos (HAR2011-22994,Ministerio de Economía y Competitividad).

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