The aim of this study was to characterize historical slags which originated during silver production from the Jihlava ore district, Czech Republic. The area was among the head producers of silver within the Lands of the Czech Crown in 13th–14th centuries. The mined ores had complex composition, being formed mostly by pyrite, sphalerite, galena, chalcopyrite, and accessory silver-rich minerals such as silver-bearing tetrahedrite (freibergite) or pyrargyrite, with gangue represented by quartz and Mn-rich carbonates or baryte. Large volumes of slags with contrasting composition were generated during the Pb-Ag production. Altogether, two main types of slags were identified in the district. The first type is characterized by high BaO contents (up to 34.5 wt.%) and dominancy of glass, minor quartz, and accessory amounts of Ba-rich feldspar (up to 93 mol.% of Cls), metal-rich inclusions, Ba-Pb sulphates and only rare pyroxene, wollastonite and melilite. The composition of the second group belongs to fayalitic slags containing glass, Fe-rich olivine, accessory pyroxene, feldspar, quartz, and inclusions of various metallic phases. Fluxes were derived from gangue (quartz, carbonates, baryte) or local host rocks for both types of slag. The calculated viscosity indexes reflect (with minor exceptions) medium-to-high effectivity of metal separation. Smelting temperatures were estimated from a series of ternary plots; however, more reliable estimates for both types of slags were obtained only from experimental determination of melting temperature and calculations using bulk/glass compositions (~1100–1200 °C).

The Sn-W ore deposits in the Krupka surroundings are associated with greisens, which occur in the upper parts of Late Variscan granitoid intrusions. Fluid inclusions were studied in samples of quartz, cassiterite, apatite, fluorite, and topaz in greisenized granites, greisens, and hydrothermal veins with Sn-W mineralization. The greisenization process took place at temperatures 370–490 °C and pressures 155–371 bars, and associated fluids had predominantly low salinity and a low gas (CO₂, N₂ and CH₄) content. The post-greisenization stage was connected with the formation of (i) low-salinity (0–8 wt. % NaCl eq.) fluid inclusions with homogenization temperatures 35 wt. % NaCl eq.) fluid inclusions with homogenization temperatures 140–370 °C, often containing trapped crystals of quartz, topaz, and sulfides, or daughter crystals of salts and carbonates, which were identified by microthermometric measurements, electron microprobe analysis, and Raman spectroscopy. Analyses of fluid inclusion leachates have shown that Na and Ca chlorides predominate in fluids. According to hydrogen stable isotopes, the source of greisenizing and post-greisenizing fluids was not only magmatogenic but also meteoric water or fluids derived from sedimentary rocks.

Pyrometallurgical remnants, including slags and technical ceramics, offer crucial insights into Early Medieval ironworking. Iron held substantial economic significance during this era and its processing is particularly evident in settlement agglomerations and proto-urban sites across Northern and East Central Europe. Despite its importance, large-scale ironworking remains inadequately explored within broader socio-economic contexts. Our study examines around 300 kg of pyrotechnical waste from the northern suburbium of the Mikulčice-Valy settlement agglomeration (Czech Republic) using macroscopic and metallographic (SEM-EDS, WD-XRF) methods. The findings reveal specialised blacksmithing characterised by intensity and diversity contributing to a better understanding of the operational dynamics and installations in craft-production workshops. We propose that blacksmiths capitalised on the proto-urban environment, satisfying a high demand for diverse iron commodities of a dense population actively engaged in household, agricultural and artisanal work. While elites facilitated access to raw materials and maintained relative peace, direct control over iron production and distribution among the elites appears limited, apart from valuables like weapons. This study sheds light on the complex interplay between ironworkers and political-economic structures, offering new perspectives on the mechanisms driving Early Medieval iron economies.

An archaeological excavation in Prostějov (Czech Republic) revealed a workshop of a local potter with colourless, pink, and blue powders presumably used to produce faience/surface decoration. A comprehensive analytical study, which combined elemental and molecular analysis techniques, was performed to shed light on the chemical composition of these unique findings. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM EDX), inductively coupled-plasma mass spectrometry (ICP MS), flow injection analysis (FIA) with electrospray ionisation mass spectrometry (ESI MS), laser desorption ionisation mass spectrometry (LDI MS), and Raman spectroscopy were applied to reveal the elemental composition of the powders and identify the colouring agents in the pink and blue powders. The colouring agents in the pink powder were probably iron and the agent in the blue powder is Prussian blue. On top of that, it was also possible to determine the organic additives in these powders through pyrolysis gas chromatography with mass spectrometric detection (Py GC/MS), atmospheric solids analysis probe ion mobility mass spectrometry (ASAP IM MS), and LDI MS. The organic constituents were identified as plant resin, beeswax, and fats. These results point to the preparation of faience/pigment mixtures as oil paint.

Hončova hůrka Hill represents an Early Cretaceous strongly altered picritic effusive body. In the low-temperature hydrothermal mineralisation of both amygdales and rock fissures, a calcite-dominated mineral association including zeolites (harmotome, ferrierite-Mg, and heulandite-clinoptilolite series), chlorite, baryte, various clay minerals, quartz, and some accessories are known. Up to this moment, the only published analysis of the heulandite-clinoptilolite series mineral was a single wet analysis proving the existence of a Ca-dominant extra-framework cation. Two hundred twenty-three new energy-dispersive (EDS) microanalyses of 11 samples revealed a much more complicated picture. Two hundred spots are classified as clinoptilolites, with a continuous transition from more common barium-rich clinoptilolite-Ca to the Ba-dominant member (4 spot analyses). Twenty-three analyses correspond to the heulandite subgroup, with a continuous transition from barium-rich heulandite-Ca to the Ba-dominant member (5 spot analyses). The electron microscope backscattered electron images revealed the lamellar structure of the crystal aggregates of the heulandite-clinoptilolite series minerals and strong zoning, with the cores richest in barium and the outer parts enriched in calcium. We believe that originally the mineral aggregates were dominantly barian, while at the end of the hydrothermal solution precipitation resulting in carbonate crystallisation (calcite, minor dolomite), there was an extra-framework cation exchange of Ba ²⁺ for Ca ²⁺ . The excess of barium at that moment stimulated baryte deposition in minute cracks of the heulandite-clinoptilolite series minerals. Four microanalyses revealing the presence of yet undescribed and unapproved clinoptilolite-Ba are not sufficient for a new phase description at this time but clearly indicate its presence in nature.