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The results of an archaeometric investigation on painted pottery obtained from the archaeological excavations carried out in Kuriki (southeastern Anatolia) are presented. It was intended to reveal the production features of the painted pottery which were occasionally unearthed from the sites dated to the Late Iron Age and Hellenistic period. The samples were subjected to spectroscopic (X-ray diffraction), microscopic (optical microscopy, scanning electron microscope/energy dispersive X-ray spectroscopy) and thermal (thermogravimetric-differential thermal analysis) analysis techniques. It was deduced from the results that most of the ceramics were produced with calcareous clay batches. This assumption was supported by high amounts of CaO (detected through EDX), presence of calcite and occasionally the neo-formations (i.e. gehlenite, pyroxene) identified by XRD. The abundance of calcareous raw materials in the vicinity of the region therefore suggested a local production for the majority of the samples. Considering the mineral/phase contents of the potsherds and insufficient vitrification behavior in micro structure, the firing temperature of the samples was found to change between 700 °C and 900 °C, but mostly in the range of 800–900 °C. TG-DTA, used as a complementary technique, brought a convenient data in terms of elucidating the mineralogical content and the production properties. The same rock type (schist) determined through the petrographic analysis (OM) suggested that the raw materials used in production originated from the same or close sources. Finally, the results are compared with the outcome of the former archaeometric studies regarding the production features of various pottery types of Kuriki belonging to different time periods. [ABSTRACT FROM AUTHOR]

Abstract: Oltu-stone is a unique black gemstone used commonly as an ornament in Turkey. The most distinctive characteristics of Oltu-stone are its strength and its reflective black appearance after polishing. It has been widely used since the 18th century as an important material for the production of quality prayer beads. This relatively hard stone is found in marine flysch and marl deposits as scattered chunks. Macroscopically, it more closely resembles obsidian than coal. Many scientists have researched the origins of this stone, but until recently, its genesis was not well understood. Its petrographical property is remarkable and quite interesting. In order to perform petrographical studies on Oltu-stone, ten samples were taken from two locations a few kilometers from the town of Oltu which is northeast of Erzurum city in eastern Turkey. Polished briquettes and thin sections were produced from the samples for petrographical examination under a coal microscope. SEM and EDS analyses were also conducted. Internal cellular structures can clearly be traced in fluorescent mode. The great strength of the stone has always incorrectly led to the conclusion that its genesis is unlike the genesis of coal. However, fluorescent light plainly revealed detailed cellular structures. With the aid of fluorescent light, suberinite textures and silicate filling of the cell cavities were clearly observed. [Copyright &y& Elsevier]

Beryllium oxide (BeO), which has a widely known single main TL peak over the main dosimetric region, is an important luminescent material widely used in personal, medical, and environmental dosimetry fields. The thermal and optically stimulated luminescence properties (TL and OSL) of the BeO dosimeter, supplied by a private company in Turkey (BeO R) that yields a double peak in the main dosimetric region (100–300 °C; heating rate = 2 °C/s) were studied. The corresponding properties were compared to the commercially prevalent Thermalox 995 BeO (BeO T). Multiple characterization techniques including x-ray diffraction analysis (XRD), energy dispersive x-ray spectroscopy (EDX), scanning electron microscope (SEM) image and electron spin resonance (ESR) were used to detect possible differences in TL and OSL signals. It was hypothesized that the calcination and or sintering process applied during the manufacturing process might lead to a double peak in the main dosimetric region of BeO R TL signals. Moreover, dosimetric properties of this dosimeter such as reproducibility, dose-response, minimum detectable dose (MDD), thermal quenching, bleaching, and thermal stability in combination with annealing properties were comprehensively investigated. An analysis of the results shows that BeO R has lower detection limits in TL than BeO T. In contrast, BeO T exhibited lower detection limits in the OSL signal than BeO R. Although both dosimeters have dissimilarities in several aspects, both are appropriate for dosimetric research on health physics applications. Therefore, selecting the appropriate BeO dosimeter could be an important factor to consider when assessing accurate doses in studies. With this outline in mind and by investigating using different characterization methods, the available luminescence knowledge base of BeO dosimeters was expanded. • Possible differences on TL and OSL signals were investigated for the two type of BeO dosimeters. • Dosimetric behaviours and kinetic parameters of BeO dosimeter were studied. • Multiple characterization techniques were applied to BeO dosimeters. [ABSTRACT FROM AUTHOR]