XRF, XRD

XPS & XRF

by farshad akhtarian

Kelta grafitos kerámia: elmélet és gyakorlat dunaszentgyörgyi kerámiák ásványtani, petrográfia és geokémiai vizsgálatának tükrében – Celtic graphitic pottery: theory and practice in the light of mineralogical, petrographic and geochemical study of ceramics from Dunaszentgyörgy (S-Hungary)

by Attila Kreiter

Havancsák, I. – Bajnóczi, B. – Tóth, M. – Kreiter, A. – Szöllősi, Sz. 2009. Kelta grafitos kerámia: elmélet és gyakorlat dunaszentgyörgyi kerámiák ásványtani, petrográfia és geokémiai vizsgálatának tükrében – Celtic graphitic pottery: theory and practice in the light of mineralogical, petrographic and geochemical study of ceramics from Dunaszentgyörgy (S-Hungary). Archeometriai Műhely/Archaeometry Workshop, 1, 39-43. (the article is in Hungarian with English abstract)

The Celtic graphitic ceramics are a distinctive type of pottery, known from most part of the Central European Celtic... more The Celtic graphitic ceramics are a distinctive type of pottery, known from most part of the Central European Celtic world. In the territory of Hungary graphitic situla-like pots were produced in great numbers from the middle La Tène period (LT B2) until the decline of the Celtic dominion (1st cent. A.D.). Widespread occurrence of graphitic (i.e. graphite-bearing) ceramics, not only around the graphite sources, suggests their extended trade. The provenance and the main distribution form (raw material, graphitic clay or finished graphitic ware) of graphite are, however, still not clear. This study was performed on graphitic and non-graphitic sherds from Dunaszentgyörgy archaeological site located in South-Hungary (LT B2-C1). Both graphitic and non-graphitic ceramics contain similar non-plastic components, mainly quartz, K-feldspar, plagioclase, muscovite, calcareous fragments, as well as apatite and
zircon inclusions in quartz and feldspar grains. In addition graphitic ceramics contain graphite in variable size (from some μm to 5 mm) and amount (up to 40%). Graphite appears as opaque individual flakes in the matrix and also occurs in metamorphic lithoclasts consisting of quartz, K-feldspar, muscovite, sillimanite, kyanite,
amphibole and tourmaline. Chemical compositions of graphitic and non-graphitic ceramics measured by X-ray fluorescence spectrometry are similar. X-ray diffraction analysis reveals that most of the sherds lack hightemperature Ca-silicate minerals and the firing temperatures of both ceramics types were usually below 850ºC,
in some cases below 650°C. Raw materials of graphitic and non-graphitic wares seem to be very similar, and both types of ware were
produced “locally”. The raw material could have been fine-grained (clayey-sandy) sediments (e.g. alluvium, loess), which are available in the wide vicinity of Dunaszentgyörgy. Graphite was imported and intentionally added to the raw material to produce a special type of ware. Graphite is derived from a medium to high grade
metamorphic rock (graphitic paragneiss), which can be found nearest in the Moldanubicum zone of the Bohemian Massif. Comparing the mineralogical composition of graphitic lithoclasts with the published petrological data, the potential source for graphite is presumably located in the Variegated Series, in the area of
the Southern Czech Republic. Our results support recent archaeological assumptions according to which the trade of raw graphite (together with the host rock), sometimes over long distances, is predominant in the La Tène period.

A petrográfiai vizsgálatok jelentősége a kelta kerámiák grafitos soványítóanyagának proveniencia meghatározásában – Significance of petrographic investigations in the determination of provenance of graphitic temper in Celtic ceramics

by Attila Kreiter

Havancsák, I. – Bajnóczi, B. – Szakmány, G. – Kreiter, A. – Szöllősi, S. –  Gáti, C. 2009. A petrográfiai vizsgálatok jelentősége a kelta kerámiák grafitos soványítóanyagának proveniencia meghatározásában – Significance of petrographic investigations in the determination of provenance of graphitic temper in Celtic ceramics. Archaeometriai Műhely/Archaeometry Workshop, 4, 1-14. (the article is in Hungarian with English abstract)

Graphite-tempered ceramics were commonly used by the Celts from Southern Germany to Transylvania and from Bohemia to... more Graphite-tempered ceramics were commonly used by the Celts from Southern Germany to Transylvania and from Bohemia to Northern Balkans in the La Tène period. One of the major scientific questions related to these ceramics is the origin of the graphitic temper added to the clay, as such ceramics have been found on archaeological sites distant from known geological sources of graphitic rocks. Thus, the first phase of the archaeometric research should focus on the petrographic investigation of graphitic rock fragments of ceramics
as it may provide information on the geological origin of the graphitic temper. Current work includes petrographic (polarizing and cathodoluminescence microscopy) study of Celtic graphitic
ceramics from Bátaszék-Körtvélyes dűlő, Szűr and Szajk archaeological sites and aims to answer the question whether the graphitic temper used by different settlements was originated from similar geological regions. Graphitic rock fragments in the ceramics are similar at all three archaeological sites and consist of graphite,
quartz, K-feldspar, plagioclase, mica (muscovite, biotite), kyanite, sillimanite, occasionally calcite, tourmaline and amphibole. The rock used as temper is medium to high grade metamorphic (amphibolite facies) graphitic gneiss containing sillimanite and kyanite index minerals. Formerly studied graphitic ceramics from Dunaszentgyörgy show similar mineralogical composition. Ceramics from Szajk contain higher amount of calcite in the graphitic rock fragments, presumably marbly graphitic gneiss was used for temper.
Graphitic rock can be originated from several possible source regions; one of them is the Kropfmühl region in Southern Germany. Comparative petrographic study has been carried out on graphitic rock samples from three deposits of the region (Kropfmühl graphite mine, Steinbruch Grögöd, Erlau). Considering the mineralogical
composition of the rock samples and the metamorphic evolution of the region, in the case of the studied archaeological artefacts the Kropfmühl region can be safely excluded as potential source area of graphite. Based on the metamorphic grade and mineralogical composition, the most probable source region of the graphitic rock fragments added to the pottery is the Variegated Unit located in the Southern Czech Republic, in the Moldanubian zone of the Bohemian Massif.

Maroslele–Panáról származó neolitikus kerámia töredékek petrográfiai, XRF és XRD vizsgálata. - The petrographic, XRF and XRD Analyses of the Neolithic Pottery from Maroslele-Pana

by Attila Kreiter

Kreiter, A. – Azbej Havancsák, I. – Sipos, P. – Tóth, M. – Viktorik, O. 2011. Maroslele–Panáról származó neolitikus kerámia töredékek petrográfiai, XRF és XRD vizsgálata. - The petrographic, XRF and XRD Analyses of the Neolithic Pottery from Maroslele-Pana. In Paluch ,T. (szerk.): Maroslele-Pana. Egy középső neolitikus lelőhely a kultúrák határvidékén. Szeged. 303-325. (the article is in Hungarian with English abstract)

Twenty-one ceramics have been subjected to macroscopic and petrographic analyses, of which five ALP and five Vinča... more Twenty-one ceramics have been subjected to macroscopic and petrographic analyses, of which five ALP and five Vinča fragments have been investigated by X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques. By the means of petrographic analysis this study aims to identify the similarities and differences between the raw materials and tempering practices of the Vinča and the ALP ceramics. X-ray diffraction analysis (XRD) was utilised to describe the raw materials of the ceramics as well as the technology of production, in particular the circumstances and temperature of firing. The major and trace elements in the ceramics have been analysed by the X-ray fluorescence method (XRF).
Based on the petrographic analysis five composition groups could be distinguished. ALP and Vinča ceramics made from very fine raw materials represent the first group. The ALP fragments in this group were tempered with vegetal material while no tempering was observed in the Vinča fragments. The second composition group represents Vinča ceramics with sand tempering. The third group is formed by ALP ceramics tempered with sand although the sand tempering shows differences in grain sizes compared to the previous group and two ceramics were also tempered with vegetal material. The fourth composition group is represented by ALP ceramics tempered with vegetal material as well as sand; the composition of the sand, however, differed from the sand used in the other groups. ALP ceramics in the fifth group were made from ‘clean’ raw materials containing much less petrographically observable non-plastic inclusions than the other groups. As indicated by the XRF analysis the major and trace element compositions of the Vinča and ALP ceramics are almost identical. That is, the examined ceramics were made from similar raw materials. A matching similarity has also been proven by the XRD analysis showing that both ALP and Vinča ceramics were fired between the temperature range of 650–850 °C.
Concerning the relationship between vessel types and ceramic raw materials there seems to be no direct correlation between vessel types and compositions since different vessel types were also produced from raw materials showing similar compositions. According to the results the Vinča ceramics were presumably made locally. Besides the typological differences of the Vinča ceramics their technological features could also be used to distinguishing them from the ALP ceramics. Although the Vinča and ALP ceramics were made from similar raw materials Vinča ceramics were not tempered with vegetal material, and for this reason their fabrics are more compact. This practice invested the vessels with ‘Vinča’ characteristic and as a result Vinča ceramics are technologically different from the ALP ones. The sand-tempered Vinča ceramics in the second group are also distinct from that of the ALP ceramics. Ceramic analyses from other Vinča sites also indicate the rarity of vegetal tempering in Vinča ceramics. The local production of Vinča ceramics at Maroslele was based on a distinct ceramic tradition from the ALP, which may indicate the former presence of potters at the site with different ceramic technological traditions. This phenomenon might point to a more complex social relationship between the ALP and the Vinča communities than trading.
Vegetal tempering is characteristic for the ALP ceramics which method, considering recent ceramic analyses, is the most common tempering practice in the Early and Middle Neolithic of Hungary. The predominant use of vegetal material for tempering has also been confirmed by Neolithic ceramic studies outside of Hungary. The ceramic technological data gained from the ALP ceramics from Maroslele correlate well with previous results, according to which there are extensive similarities amongst the ceramic traditions of Neolithic cultural groups. The most important similarity is the consistent presence of vegetal tempering that occurs regardless of vessel type and size and there seems to be no correlation between vegetal tempering, vessels type and size.