Fibula and Snake Bracelet from Albania. a Case Study by Om, Sem-Eds and Xrf

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DOI: 10.5281/zenodo.44895

FIBULA AND SNAKE BRACELET FROM ALBANIA. A CASE STUDY BY OM, SEM-EDS AND XRF.

Olta Çakaj1, Teuta Dilo1, Gert Schmidt2, Nikolla Civici3, Frederik Stamati4 1Faculty of Natural Science, University of Tirana, Albania 2Institut für Keramik, Glas- und Baustofftechnik, TU Bergakademie Freiberg, Germany 3Centre of Applied Nuclear Physics, Albania 4Centre of Albanological Studies, Tirana, Albania

Received: 20/11/2015 Accepted: 17/01/2016 Corresponding author: Olta Çakaj ([email protected])

ABSTRACT

Albania is situated west of the Balkan Peninsula while Shkodra and Durrës are respectively north-western and western cities. The objects of this study are a fibula (IX-VIII BC) found in Shkodra and a snake bracelet (III-I BC) found in Durrës. The purposes of this research paper are to study the chemical composition, production technology, corrosion products, microstructure and the possible minerals used for the objects’ man- ufacture. To fulfil these tasks the objects’ samples have been analysed with μ-XRF, OM, Vickers microhardness tester and SEM-EDS. Both objects resulted authentic copper-tin alloys with less than 2% of lead. They have approximate microhardness values (116.2HV and 113.6HV), with corrosion products from the first and second oxidized layer. The fibula and the snake bracelet has been casted, hot and cold worked to obtain the final shape. Both objects have lead and copper-iron-sulphur inclusions which suggest the possible use of copper-iron sulphite minerals.

KEYWORDS: antique bronze, microstructure, texture, OM, SEM-EDS, μ-XRF

10 Olta Çakaj et al

1. INTRODUCTION in Cyprus since early times that its name derives from this chemical element. The copper ores of Cy- This research was performed in order to study prus are hydro carbonate and sulphate such as mala- the alloy composition of two antique objects, their chite (Cu2CO3(OH)2), azurite (Cu3(CO3)2(OH)2) and distinct production technology and the possible chalcopyrite CuFeS2. (Constantinou 1982) While in mineral used as raw material. This was archived Greece the regions rich in copper ores where is through the examination of the samples’ chemical thought that objects production was supported by content, their microhardness, microstructure and its local copper deposits are Kamariza, Ilarion, Christi- inclusions or secondary phases. Another section of ana, Agia Varvara, Sounion and Lavrion. According the article covers the qualitative determination of the to the literature copper was obtained from native corrosion products which is essential to prove the copper (Cu), cuprite (Cu2O), chalcopyrite (CuFeS2), objects’ authenticity (not fake replicas) and is helpful malachite (Cu2CO3(OH)2), azurite (Cu3(CO3)2(OH)2), for the conservation process. chalcocite (Cu2S), covellite (CuS), olivenite Albania has a favourable link position between (Cu2AsO4OH), atacamite (Cu2Cl(OH)3) and tetrahe- Europe and Asia. Scodra (in Latin, today Shkodra) drite ((Cu,Fe)12Sb4S13) (figure 1a). (Marinos & Pet- on the northwest of Albania was the capital of Ardi- rascheck 1956) aei kingdom since the III century BC. While Dyrra- Few studies have been performed about Albanian chium (in Latin, today Durrës) was founded during copper based objects this last years while other Bal- the XIII - XI century BC and became one of the most kanic countries have studied nearly all their culture important port cities of the western Balkan Peninsula heritage with physical and chemical analytical (figure 1a). After the XI century BC the first iron ob- methods. Although Albania has a rich museum fund jects began to appear marking the initiation of the only a few objects have been studied so far. 122 sil- Iron Age but it took almost three centuries for this ver alloy coins from a hoard (III B.C.), minted by the new chemical element to substitute partially bronze Illyrian king Monounios and the ancient cities of in working tools and weapons. During this time Dyrrachium (Durrës) and Korkyra (Korfuz) was copper alloys were more preferable in the produc- studied with EDXRF. One coin from Dyrrachium tion of ornaments and jewellery. Later on the Hellen- (Durrës) and one of Illyrian king Monounios from istic Period was associated with the spread of Greek the III century B.C. resulted copper-silver alloys culture influences and trade exchanges during the produced with a cold-struck process after casting. expansion of the Empire founded by Alexander the (Pistofidis et al., 2006; Civici et al., 2007) Another Great. (Prendi 1977-1978; Boardman et al. 1982; coin from Dyrrachium (Durrës) of the III-II century Jacques 1995; Ceka 2000) B.C. was determined to be a copper-tin-lead alloy Most of the copper deposits from the Jurassic and produced in a similar way compared with the coins Cretaceous periods are present in the volcanogenic mentioned above. One nail from Dyrrah used in massive sulphide compositions. They are located in land (IV-III B.C.) and one from Saranda used in a Albania, Cyprus and a few in Turkey (Kure Asikoy, ship (VI-IV B.C.) resulted pure copper which were Murgul Maden, etc.) but are very rare in other coun- hot worked after being casted. (Dilo et al., 2009) A tries. (Economou-Eliopoulos et al. 2008; Hoxha 2014) necklace (VII-VI B.C.) and a belt application (VII-VI Many chemical mineralogical studies have been per- B.C) from Shkodra were casted copper-tin-lead al- formed through the years for the Albanian territo- loys while a button (VI-IV B.C) from the same region ries. The central north (Rubik) and north (Mirditë) resulted a casted copper-tin composition. (Çakaj et underground resulted rich in copper-sulphide min- al., 2014) Some weapons were studied as well such erals associated with zinc such as pyrite (FeS2) - chal- as six swords, three spearheads and a shield from copyrite (CuFeS2) - sphalerite [(Zn,Fe)S]. Later on the south-west and south-east of Albania. The shield because of the hydrothermal solutions changes and from Apollonia (Fier, south-west Albania) was a the partial oxygen pressure increments the quantity copper-tin alloy produced throught hot working af- of chalcopyrite mineral had decreased and bornite ter casting. While one sword from Erseka (south-east (Cu5FeS4) had taken its place (figure 1b). (Çina 1975, Albania), five swords of type Naue II and three 1976; Koçi 1977; Kati 1988) Two ancient and im- speardheads from Korça (south-east Albania) result- portant mines in the region are Rudna Glava of Ser- ed copper-tin alloys. (Koui et al., 2006; Çakaj et al., bia and Ai Bunar of Bulgaria. According to different 2009) Also some copper alloy sculptures from An- studies their copper mineral deposits are hydro car- tigonea have been studied for restoration and con- bonate such as azurite (Cu3(CO3)2(OH)2) and mala- servation reasons. (Budina and Stamati, 1989) chite (Cu2CO3(OH)2). (Jovanovic 1978; Gale 1990)

The copper sources were so many and so important

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a) b) Figure 1. a) Political map of the Balkan Peninsula and the Near East. It shows ancient copper mines in Serbia (Rudna Glava), Bulgaria (Ai Bunar), Lavrion (Greece); copper rich regions in Cyprus and in northern Albania (Mirditë). This study objects were found in Scodra and in Dyrrachium. (http://www.worldatlas.com/webimage/countrys/europe/balkans.htm). b) The extension of FeS2-CuFeS2 and FeS2- CuFeS2-(Zn,Fe)S ores in Albania. Regions rich in copper ores (Mirditë, Rubik), objects’ excavation locations (Scodra, Dyrrachium), excavation locations of former studied objects (Shkodra, Durrës, Saranda, Apollonia, Antigonea, Erseka, Korça), the Albanian capital (Tirana). (Economou-Eliopoulos, Eliopoulos, and Chryssoulis 2008.)

tion). This fibula has no visible clip on the back side 2. MATERIALS AND METHODS and its total length is approximately 2.3m. The snake Sample from the fibula and the snake bracelet bracelet (III-I BC. Hellenistic Period, object no. 60205, was removed using a small pincers and in both cases code 029, file no. 9786) comes from the Hellenistic it didn’t exceed 6mm3 in volume (Figure 2a). The Period, has a diameter of 0.047m, the height of spi- sampling process was carefully carried out in order rals is 0.032m and the total length is 0.7m. The cross to have almost no impact on the object integrity and section of the fibula is 3.2∙10-6m2 and the one of the to collect as much information as possible. The fibula snake bracelet is 4∙10-6m2. Both objects have no visi- (IX-VIII BC Iron Age, object no. 17960, code 015, file ble defects and the cross section is approximately the no. 485) dates back to the Iron Age and has a spiral same along the whole length. (Prendi 1958, 2008) string that forms two round discs 0.065m in diameter Figure 2a) shows the objects’ photos while 2b) shows connected together (0.145m length from one side to their sketches. the other) while each disc has a conical button on the centre (the two discs found separated in the excava-

a) b) Figure 2. a) Photos of the fibula (left), the snake bracelet (right) along with the positions where each sample was taken, b) the corresponding objects’ sketches. The examine procedure starts with µ-X ray paper (30μm, 18μm, 5μm) and cloth with diamond fluorescence (µ-XRF) performed on 2-3 spots of the paste (3μm, 1μm)associated with DP-Lubricant Blue. objects’ cleaned surface (without varnish) to deter- Vickers tester (attached on the Metalloplan Leitz mi- mine the alloy composition, taking account that the croscope) was used to measure the microhardness objects are chemically homogeneous. The equipment values of the samples. Kozo XJP304 optical micro- used was transportable µ-XRF spectrometer ARTAX scope (OM) with reflected and polarized light along Bruker (60μm spot diameter, detective capacity from with Sony TCC-8.1 digital camera and View Version Na to U) with Spectra ARTAX Version 7.2.5.0 and 7.3.1.7 image analysis software were used to observe M-Quant-Calib (BRUKER) software. After this the the corrosion products and the microstructure. samples (less than 12∙10-9m3) were prepared Scanning electron microscope-energy X ray disper- through mounting in epoxy resin, polishing with SiC sive spectroscopy (SEM-EDS) XL30 ESEM-FEI with

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EDAX Genesis Spectrum software was used to study sion products. The metal spots on the fibula were the microstructure’s inclusions / secondary phases. chosen randomly while in the snake bracelet case, In order to observe the microstructure the samples the first examine was performed on the snake head were etched with aqueous ferric chloride solution meantime the other on the bottom edge. Figure 3 (H2O : HCl : FeCl3 = 12ml : 3ml : 1gr) for several se- shows the μ-XRF spectra of the first spot examined conds. (Goldstein et al. 2003; MIT 2003; Potts & West on each sample while table 1 lists the chemical ele- 2008; Wayne 2009). ments’ quantitative results with the corresponding standard deviations for all the analysis. 3. RESULTS AND DISCUSSIONS For each of the objects were chosen two spots on the cleaned metal surface and one spot on the corro-

a) b) Figure 3. μ-XRF spectra of the first metal spot examined on a) the fibula and b) the snake bracelet. The alloy results Cu and Sn with minor elements such as Pb, Fe, Ni, As and Cr.

Table I. µ-XRF results (elements percentage with the from the soil content where the objects were pre- standard deviation) for a) the fibula and b) the snake served through the centuries or from the mineral bracelet. used for the alloy production. According to the Cu- Sn phase diagram (usual casted condition) the alloy a) Fibula (IX-VIII BC) at low temperatures and low tin percentage is com- Element Metal spot 1 Metal spot 2 Corrosion spot posed by α and δ eutectoid phases. The Cu31Sn8 δ Cu (%) 91.79±2.66 90.95±4.28 28.5±0.8 phase is a crystalline solid intermetallic compound Sn (%) 6.35±0.38 6.93±0.6 53.49±1.91 which tends to be very hard with no ductility. The Pb (%) 0.95±0.08 1.34±0.16 5.57±0.33 Fe (%) 0.55±0.02 0.42±0.03 3.33±0.11 composition of Cu and Sn in the δ phase is fixed Ni (%) 0.21±0.01 0.18±0.02 0.32±0.02 (Cu:Sn=67.47%:32.53%) while the α phase can absorb As (%) 0.16±0.04 0.18±0.07 1.71±0.17 more or less Sn according to the alloy consistence. Ca (%) – – 7.07±2.84 Furthermore for bronzes with tin between 5-10% the Cr (%) – – – adding of lead makes the alloy less viscous. For very b) Snake bracelet (III-I BC) low lead content such as this study objects the in- Metal spot- Metal spot- crease of the tin percentage causes the decrease of Element Corrosion spot head bottom the material ductility or the elongation value (fibula Cu (%) 89.11±4.3 88.26±3.32 55.77±1.78 40%-50% and snake bracelet 20%-30%). (Scott 2012) Sn (%) 9.05±0.76 9.46±0.65 37.68±1.69 The Cu percentage decreases in the outer surface Pb (%) 1.55±0.12 2.06±0.12 6.04±0.25 Fe (%) 0.24±0.02 0.21±0.01 0.5±0.03 while Sn percentage increases because of their dif- Ni (%) – – – ferent diffusion coefficients and the formation of cor- As (%) – – – rosion products of both elements (oxide and hydrox- Ca (%) – – – ide). (Dillmannet al. 2007) On the corrosion spots Cr (%) 0.04±0.01 – – oxygen is not detectable with μ-XRF and its percent-

age is added by the software to the other present From the μ-XRF data obtained the fibula and the detectable elements (overestimation) in order to snake bracelet resulted copper-tin alloys with lead have a total of 100%. This can be observed in the μ- content around 1.14% and 1.8% respectively. The tin XRF results of the corrosion spots analysed on each percentage in the fibula’s alloy is around 6.64% and sample. Figures 4, 5 show the corrosion products the one in the snake bracelet is around 9.25%. Other observed with polarized light OM for the fibula’s chemical elements such as Fe, Ni, As and Cr present sample and the snake bracelet’s one respectively. less than 0.6% in the metallic alloys may originate

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Figure 4. Fibula’s corrosion products, photo obtained using OM with crossed nicols polarized light (left) and parallel nicols polarized light (right). Corrosion products introduced far inside the alloy. Present main phases that differ in colours are CuO, Cu2O and Cu2CO3(OH)2.

Figure 5. Snake bracelet’s corrosion products, photo obtained using OM with crossed nicols polarized light (left) and parallel nicols polarized light (right).Corrosion products introduced far inside the alloy. Present main phases that differ in colours are CuO, Cu2O and Cu2CO3(OH)2. It is clear from figures 4, 5 that the corrosion the surrounding soil. The corrosion phases can be products are introduced far inside the alloy. Differ- identified with XRD analysis or the main ones that ent colours are visible on the polarized light OM differ in colours can be specified through observing photos (crossed nicols) for both samples such as the corrosion products with a microscope (polarized bright and dark red mixed with brown areas over- light) along with an optical mineralogical manual. lapped by bright and dark green. The observation of (Vink 1986; Pracejus 2008; Sandu et al. 2008, 2014). corrosion for both samples (figure 4, 5) leads to the Table 2, 3 shows the EDS results of all examined conclusion that the objects are authentic (not fake areas and points for the fibula’s and snake bracelet’s replicas) because of these products’ introduction far sample. inside the alloy which can’t be done artificially in a Table 2. EDS results for the fibula (mean value of standard short time. deviation ±0.3%). Based on the different corrosion colours from the OM crossed nicols polarized light photos the main Element Point A Area B Area C Area D Cu (%) 08.00 91.81 65.36 06.62 phases present might be tenorite CuO (brown), cu- Pb (%) 86.53 – – 53.81 prite Cu2O (red) from the first corrosion layer and O (%) 05.46 – – 21.67 malachite Cu2CO3(OH)2(green) from the second one. Sn (%) – 08.19 – 10.83 (Pracejus 2008) The first corrosion layer is formed S (%) – – 25.67 07.07 Fe (%) – – 08.97 – during the production process and the object’s usage. It is mainly composed by tenorite CuO (dark Table 3. EDS results for the snake bracelet (mean value of standard deviation ±0.3%). brown with red internal reflections), cuprite Cu2O (bright/dark red) and SnO / SnO2 / Sn(OH)2 (grey Element Area A Area B Point C colour shades). The second corrosion layer overlaps Cu (%) 61.84 91.24 79.21 the first one and appears during the end of the usage Pb (%) 29.31 – – O (%) – – – period. The distinguish green colour comes from Sn (%) 07.07 08.76 – malachite Cu2CO3(OH)2 but also from nantokite S (%) 01.78 – 19.42 CuCl and antlerite Cu3SO4(OH)4. When the percent- Fe (%) – – 01.37 age of CO2 is high in contact with the object other phases are formed such as azurite Cu3(CO3)2(OH)2 Figures 6, 7 show the SEM images of with the (blue) and cerussite Pb2CO3(OH)2 (light grey). Last EDS examined areas or points along with the corre- comes the third corrosion layer which is formed dur- sponding spectra for both samples. ing the object’s burial and includes compounds from

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Figure 6. Photos obtained with SEM of the fibula’s sample along with the EDS area/point analysis and spectra. The bright inclusions are rich in Pb while the dark ones are Cu-Fe-S inclusions. The alloy is composed by Cu-Sn and the corrosion area contains oxidised Cu, Pb, S and Sn.

Figure 7. Photos obtained with SEM of the snake bracelet’s sample along with the EDS area/point analysis and spectra. The bright inclusions are rich in Pb but also S while the dark ones are Fe-S inclusions. The alloy is composed by Cu-Sn. In both samples the EDS examination on the alloy (table 2) were also the ones detected with μ-XRF on (area B in both objects) confirms the μ-XRF results the corrosion products (table 1). taking account the standard deviation as well. Bright The present of Cu-Fe-S inclusions in the alloy and dark inclusions are visible in the SEM photos of may be an indication of sulphide mineral usage in both alloys. After the EDS analysis all the bright in- the production procedure. This mineral mainly conclusions resulted rich in Pb while all the dark ones sists of copper sulphide and copper-iron sulphide are mainly composed of Cu-Fe-S. Although only one compounds that do not mix well with metallic cop- EDS analyse of these inclusions for each sample is per and one of which is bornite Cu5FeS4. (Shugar shown in this study. 2003; Ashkenazi et al. 2012) A comparison between If the analysed area/point is smaller than 5μm the Cu-Fe-S experimental percentages of the fibula’s (the average dimension of the interaction volume) is area C with the elements’ weigh consistence in probable that the detection of the alloy elements Cu Cu5FeS4 was made. Area C is composed by and Sn comes from the surrounding area. This is the 65.36%Cu - 25.67%S - 8.97%Fe (table 2) while the case of the examined point A on the fibula sample weight percentages of these elements in Cu5FeS4 are and area A / point C on the snake bracelet sample. 63.32%Cu - 25.55%S - 11.13%Fe. This can suggest the Only one corrosion area was analysed on the fibula possible use of bornite in order to produce the fibu- sample (area D) and among the chemical elements la’s alloy. (Figueiredo et al. 2011)

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Table 4 shows the Vickers microhardness results Table 4. Measured and calculated mean values of the along with the mean value for both samples. The Vickers microhardness test (absolute error in measuring fibula sample has a mean Vickers microhardness the Vickers microhardness is ±1HV). value of 116.2HV while the snake bracelet’s one is HV Fibula (IX-VIII BC) Snake bracelet (III-I BC) around 113.6HV (absolute error ±1HV). Adding ad- Test 1 117 123 ditional chemical elements in copper (alloying) and Test 2 109 121 Test 3 116 114 submitting the metal to different mechanical / ther- Test 4 121 115 mal processes can increase the Vickers microhard- Test 5 119 107 ness value from 40-50HV (pure casted Cu) up to Test 6 115 109 220HV (fully worked Cu-Sn alloy). For the same per- Test 7 – 106 Mean value 116.2 113.6 centage of Sn the adding of Pb can slightly decrease the microhardness and on the other hand it increases Figure 8 a), b) and figure 9 a), b) show the fibula’s after the order of the processes: casted → worked and the snake bracelet’s respective microstructure and annealed → cold worked. (Scott 1991) using OM with reflected light and SEM.

a) b) Figure 8. Fibula’s microstructure, photos obtained using: a) OM with reflected light etched for 1-2 seconds and b) SEM. The OM photo reveals twins (1), strain lines (2) and (3) elongated / orientated δ phase in the microstructure while the both OM - SEM photos show elongated / orientated Pb inclusions (4).

a) b) Figure 9. Snake bracelet’s microstructure, photos obtained using: a) OM with reflected light etched for 5 (above) and 7 (below) seconds and b) SEM. The OM photo reveals twins (1) and strain lines (2) in the microstructure while the SEM photos show no texture. According to the fibula’s OM reflected light pho- into account that lead has a significantly lower melt- to the presence of twins and some strain lines (figure ing point compared to copper, the most probable 8a) suggests that the alloy might have been firstly production technique might be the one where the casted then cold worked and at the end annealed alloy after casting has been hot worked in order to (hot worked). Another possible production process obtain the object’s final shape. (Mortazavi et al. 2011; starts with casting then annealing and last cold / hot Ashkenazi et al. 2012) working. Adding Pb in Cu alloys increases the fluid- On the snake bracelet’s microstructure (figure 9a) ity during casting but it’s not suitable in high per- from the OM photos with reflected light are clearly centage for bronzes that will be hammered because visible twins and strain lines. According to the litera- lead can decrease the alloy ductility. This happens ture the alloy has been initially casted, then it might because Pb is not soluble in Cu, it usually segregates has followed these possible processes: 1) cold in grain boundaries and during hammering the worked, annealed and again cold worked at the end propagation of cracks can occur along Cu-Pb inter- or 2) hot and cold worked to obtain the final shape. faces. It is clear from the OM and SEM figure 8 a), b) On the SEM photo (figure 9b) of the snake bracelet’s that the Pb and Cu-Fe-S inclusions are elongated and sample no texture is visible, meaning that the Pb and orientated in one direction evidencing a texture mi- Cu-Fe-S inclusions have no orientation and are not crostructure caused by probable hammering. Taking elongated in one specific direction.

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Based on the literature after the alloy is casted the Albanian copper ores brings to the assumption that microstructure is composed by dendrites (like fern- local sulphite minerals might have been used as raw like growth) which can lead to bent ones after cold material. working or to hexagonal grains after the alloy has According to the OM photos with polarized light been annealed (hot worked). If the bent dendrites the first and second corrosion layer main phases are microstructure is annealed (hot worked) a twinned present in both samples. Based on these products’ one will be obtained. On the other hand the twinned insertion far inside the alloy both objects result au- microstructure can also derive from hot working the thentically antique ones. hexagonal grains’ alloy. The increase of the alloy The SEM and OM with reflected light photos strength from cold working is higher compared with show the presence of twins, strain lines, orientated the one from hot working but in both cases the duc- elongated Pb and Cu-Fe-S inclusions, δ phase and tility of the material decreases. Further cold working pores in the fibula’s microstructure. The presence of can bend the twins and create stain lines. (Scott 2012) twins and strain lines is very clear on the OM photos with reflected light of the snake bracelet’s sample. 4. CONCLUSIONS This might be explained if the objects after casting Different analytical methods were used in this have been hot worked probably by hammering and study in order to have the fibula’s and snake brace- then cold worked where the final shape has derived. let’s characterization as complete as possible. The Pb and Cu-Fe-S inclusions in the snake bracelet’s From the μ-XRF examination both alloys are α + sample (SEM photo) result not elongated and orien- δ phases Cu-Sn with the addition of low percentage tated. The Vickers microhardness value is 116.2HV of Pb. The fibula is composed by 6.64% Sn and 1.14% for the fibula and 113.6HV for the snake bracelet. Pb meanwhile the snake bracelet has a higher con- These objects are evidence of unique and distinct sistence of the two elements respectively 9.25% Sn handicraftsmen skills in metal processing since the and 1.8% Pb. Soil chemical elements are present in IX-VIII BC in Albania. By using simple tools such as both samples such as Fe, Ni, As, Ca, Cr. hammers and furnaces the handicraftsmen were able The EDS results of the alloy area confirm the μ- to produce beautiful wire-like ornamental objects XRF analysis. The SEM-EDS analysis show the pres- with considerable length and no visible defects. ence of Pb and Cu-Fe-S inclusions. This result and based on the geological - mineralogical studies of

ACKNOWLEDGEMENTS

The authors are very grateful to the Archaeological Department, Historical Museum of Shkodra and the In- stitute of Cultural Monuments in Tirana for providing the objects for this study; the Centre of Applied Nu- clear Physics, the Faculty of Natural Sciences, UT, Albania and the Institut für Keramik, Glas- und Baustofftechnik, TU Bergakademie Freiberg, Germany for their support with analytical equipment and fund- ing. The authors would like to thank DAAD for financially sustaining the analysis performed in Germany and project coordinator Prof. Dr. Thomas Bier. Last but not least the authors are grateful for the unremitting collaboration of Mr Zamir Tafilica (archaeologist) and Mrs Edlira Çaushi (restorer).

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SCIENTIFIC CULTURE, Vol. 2, No 2, (2016), pp. 9-18 Fibula And Snake Bracelet From Albania. A Case Study By OM, SEM-EDS And XRF. 17

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