Abstract
The pseudo-amorphous clay components of some of the pottery sherds that formed a surface in the firing chamber of a Late Byzantine kiln were shown by Fourier Transform Infrared Spectroscopy to have undergone almost complete recrystallization. Powder X-ray diffraction showed that the crystalline montmorillonite component of these sherds increased and kaolinite formed de novo. As this recrystallization process only occurred in the center of the firing chamber, we infer that the recrystallization process was due to repeated exposure of the sherds to high temperatures. The zeolite gonnardite was identified by X-ray diffraction. The chemical compositions of sodium-rich minerals, determined by energy dispersive X-ray spectroscopy (EDS), are consistent with the presence of gonnardite and analcime, and showed that the sodium was partially substituted by calcium and other cations. As these zeolites were also present in sherds from the upper pottery chamber, they did not form only as a result of repeated exposure to high temperatures. The demonstration that the clay mineral component of ceramics can undergo diagenetic recrystallization supports the possibility that provenience studies based on elemental analyses, especially of cooking pots that are repeatedly exposed to high temperatures, may be affected by recrystallization.
Original language | English |
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Article number | 408 |
Number of pages | 12 |
Journal | Minerals |
Volume | 10 |
Issue number | 5 |
DOIs | |
Publication status | Published - May 2020 |
Funding
We thank Iddo Pinkas, Weizmann Institute of Science, for his help in this project, as well as Filipe Natalio, Weizmann Institute of Science, for preparing the thin sections. We also thank Louise Gomart for her critical reading of the manuscript and valuable suggestions. Funding - : This research was in part funded by the Kimmel Center for Archaeological Science of the Weizmann Institute of Science. Author contributions - S.W., Y.F. and A.K. all participated in the data analysis and writing of the manuscript. A.N. directed the excavation. All authors have read and agreed to the published version of the manuscript.