Basics of X-ray DiffractionH. Stanjek Institut für Mineralogie und Lagerstättenlehre, Rheinisch Westfälische Technische Hochschule, 52056 Aachen, Germany W. Häusler Physik-Department E15, Technische Universität München, 85747 Garching, Germany Preliminary Information X-ray diffraction (XRD) is the most comprehensive tool to identify minerals in complex mineral assemblages. The method is briefly described with special emphasis on clay and ceramics. As an example, an investigation of graphite-containing pottery sherds by XRD is presented. By comparing the measured XRD data with the patterns simulated by the Rietveld method, the graphite content of such samples could be determined. Full Article * Reprints can be requested from urwagner@gmx.de Firing of Clays Studied by X-ray Diffraction and Mössbauer SpectroscopyW. Häusler Physik-Department E15, Technische Universität München, 85747 Garching, Germany | ||
Preliminary Information Three bentonites of varying purity were fired in air under controlled conditions up to 1300°C in an attempt to provide data for the assessment of firing techniques used in prehistoric pottery making. X-ray diffraction of samples heated at increasing temperatures allows to study the mineral transformations, the breakdown of the clay structure and the formation of new minerals in the high-temperature region. Mössbauer spectroscopy reveals the change of valence state and of the environment of the iron atoms on heating. Non iron-bearing minerals are only accessible by X-ray diffraction, while iron-containing oxidic and amorphous phases may be difficult to detect, due to poor crystallinity and small particle size. The combination of X-ray diffraction and Mössbauer spectroscopy therefore has a considerable potential in the study of the chemical and physical transformations occurring in pottery clays during firing. Full Article * Reprints can be requested from urwagner@gmx.de | ||
Last update: 05.10.2007 | ||
