Archaeomineralogy

Ceramics are a key indicator for the study of cultural heritage:-A valuable technological indicator because (a) ceramics mark the passage from the simple exploitation to the complex control of fire; (b) they represent the first pyrotechnological product of a certain complexity; and (c) they are able of triggering the development of other technologies such as those involving the processing of metal and glass.-A valuable socioeconomic indicator because (a) ceramics are brought into the houses of both poor and wealthy families; (b) they provide evidence of trade routes and cultural exchange; and (c) they are able to pass on significant information about the evolution of aesthetic taste as well as dietary habits through the centuries.-A valuable chronological indicator because (a) their comparative study can provide accurate dating; (b) they can provide absolute dates by thermoluminescence testing; and (c) they enable the dating of other materials found in stratigraphic association. In this framework, research questions are discussed according to the different steps of a typical research project in progress: from the individuation of the archaeological site or area, to the selection of the ceramic types to be investigated and the samples to be taken for the analyses. It is proposed that research questions should contribute to the reconstruction of a "big picture" covering wide and complex issues such as the circulation of a specific type of goods within large geographic areas and/or the diachronic evolution of production technology. It can be demonstrated that farsighted strategy in research planning can provide material for preliminary articles that satisfy professional obligations to publish periodically while also laying the groundwork for truly important contributions to the field. The distinct fields of provenance, technology, function, use, chronology and conservation are briefly reviewed in order to provide an introductory framework to the following contributions of this Topical Collection. As for research design, the aim here is to reaffirm the importance of typology and contextualization as the basis for all studies undertaken. Finally, it is demonstrated that true multidisciplinary collaboration, rather than working in silos according to different specializations, provides the best approach to obtaining accurate and meaningful results. Premise This paper serves as an anchor to the Topical Collection (TC) "Ceramics: Research questions and answers" aimed at guiding researchers in the study of archaeological ceramics from excavation to study and preservation in museum collections. Each contribution has a tutorial approach covering one of the main issues pertaining to the study of ceramics: research questions and sampling criteria (this paper); the chemical (Hein and Kilikoglou 2020) and mineralogical-petrographic

Abstract. At the European recent Prehistory variscite was a precious gemmological material that appears in scarce megalithic burials of the Atlantic facade, especially at the Iberian peninsula and West France.
Here we describe the main results of the mineralogical and geochemical analysis of a great and diverse group of archaeological and geological variscite and turquoise samples from the Iberian peninsula, especially from the Atlantic facade and the SW of Spain. Samples were analysed last years by the use of different analytical techniques as XRD, WDXRF, ICP-MS-LA and PIXE and stereomicroscopy.
The geochemical results, obtained especially by PIXE and ICP-MS-LA techniques, on these archaeological samples were discussed in relation to their possible provenance areas, related with the three main geological areas with variscite and turquoise outcrops in the Iberian peninsula: Palazuelo de las Cuevas- San Vicente area, that included other sites as El Bostal and Bragança district in Portugal; Pico Centeno mines, Encinasola area, in Huelva province, SW Spain; Gavá mines in Catalonia, NE Spain, and other possible sources in Europe as Pannecé, France.
Geochemical data were subjected to statistical analysis selecting different chemical variables in variscites and turquoises. A relatively good discrimination has been obtained through an interactive geochemical model using specially the Fe-Cr-V relationship, represented by a triangular diagram and the elementary relationships between other chemical elements.
These results show the existence, in Neolithic and Chalcolithic times, of great exchange networks of exotic or prestige lithic products that extended in Western Europe, hundreds and thousands of kilometres away from their source areas.

During excavations at two sites of the La Tène culture in Samborowice, Upper Silesia, stone artefacts made from quartz-sericite schist were found. Deposits of this mineral are located in one place only, a hill massif situated in the vicinity of Jegłowa in Lower Silesia. The discussed finds were discovered within a context of precisely dated artefacts of the La Tène culture, which confirm the beginning of use of quartz-sericite schists as early as the onset of the Middle La Tène period. The finds from Samborowice are evidence for the existence of contacts and an organised exchange network between two local communities of the La Tène culture. This has been difficult to prove until recently on the basis of known archaeological finds.

Previous research (powder X-ray diffraction, optical microscopy, and SEM) revealed that the found slag fragments consisted mainly of crystalline fayalite and intersticial glass, and minor magnetite. In places slag contains macroscopic to microscopic oval iron prills as well as minute troilite blebs a few microns across. Here we present first data on the chemical composition of the already identified slag phases for further examination of the slag found and elucidation of the metallurgical activity which has produced it.

En las ofrendas del Templo Mayor de Tenochtitlan en la Cuenca de México, los mexicas depositaron miles de piezas de turquesas en diferentes ofrendas. Gracias a los análisis de composición no destructivos fue posible determinar que la gran mayoría de las piezas eran turquesas químicas o geológicas del Noroeste de México y del Suroeste de los Estados Unidos. Sin embargo, ¿qué simbolismo tenían los objetos? ¿dónde fueron elaborados y con qué instrumentos y técnicas? Para tratar de resol-culturas, encontrando que formaban discos de mosaico y ornamentos de determinadas deidades nahuas, y eran parte de la decoración de cuchillos, rostros y cetros. También se aplicaron análisis tecnológicos con arqueología experimental para caracterizar las huellas de manufactura con Microscopía Electrónica. Se detectaron tres patrones: uno relacionado con los mixtecos, otro que parece tener un origen no mesoamericano y un último que comparte la tecnología del estilo imperial tenochca. Así mismo, se revisaron los mosaicos de turquesa iconografía, armado y composición. Palabras clave: turquesa; mexicas; estilo; tecnología; simbolismo.