Within the Variscan Karkonosze pluton (NE Bohemian Massif), the Szklarska Poręba Huta quarry hosts multistage post-magmatic mineralisation disseminated in aplogranites, pegmatites, and quartz veins, comprising W-Sn-Mo-Bi and Th-Nb-REE assemblages. In this study, diverse Bi sulphides, sulphosalts, and chalcogenides were identified and characterised, and trace-element compositions of associated base-metal sulphides were determined to reconstruct the crystallisation sequence and metal distribution during hydrothermal fluid evolution.LA-ICP-MS data reveal strong geochemical contrasts between base-metal sulphides from aplogranites and quartz veins. The mineralisation records a transition from late-magmatic to hydrothermal conditions, defining three successive, partly overlapping stages within a mineralising continuum. Early aplogranite-hosted mineralisation was dominated by pyrite–pyrrhotite, accompanied by W-Sn-Mo minerals, other base-metal sulphides, bismuthinite, and bismuth. Pyrite from this stage shows high enrichment in Mo, W, As, Co, and Ni, with progressive Ni depletion relative to Co as temperature decreases. Subsequent quartz-vein mineralisation was initially characterised by abundant W-Sn-Mo minerals associated with Fe-sulphides, which show continued Ni depletion followed by a decrease in Co availability. With progressive cooling, chalcopyrite and sphalerite became dominant, incorporating Cd, Ag, In, and Sn from the mineralising fluids. Bismuth and bismuthinite were also present, accompanied by the crystallisation of rare Pb-Bi-Ag sulphosalts. The late stage was characterised by various Cu-Bi sulphosalts, Bi chalcogenides, and a second generation of base-metal sulphides.Paragenetic and trace-element data indicate that base-metal sulphides and Bi-bearing phases crystallised over a broad temperature range from ≥ 400 to ∼200 °C during progressive cooling and fluid fractionation, reflecting changes in fS2 and redox state. These parameters controlled the distribution of base and critical metals among successive mineral assemblages throughout the system evolution. The Szklarska Poręba–Huta mineralisation provides new insights into the mechanisms responsible for the development of CRM-bearing granite-related mineralising systems in the Bohemian Massif and Central Europe.

The Kolchiko polymetallic vein-hosted mineralization is part of a broad mineralization system in the Vertiskos crustal unit in northern Greece, which includes several gneiss- and mica-schist-hosted gold, copper and antimony bearing quartz veins. Mineralization includes gold-bearing arsenopyrite and pyrite, chalcopyrite, sphalerite occurring in massive to disseminated forms in quartz-veins, as well as quartz-pyrite veins. The mineralized veins are enveloped by hydrothermal halos related to sericitization of the mica-schist host rocks. Arsenopyrite and pyrite are the most abundant ore minerals, while enrichment in bismuth (<992 ppm) and tellurium (<3 ppm) are related to the variable occurrence of galenobismuthinite, hessite, tellurobismuthite and native bismuth. Particularly gold is enriched (<9.2 ppm) in the massive veins. The ore parageneses, the mineral chemistry analysis and the fluid inclusions imply that the mineralization formation was characterized by two stages of magmatic-hydrothermal activity: 1) an early higher temperature (T = 300 to 444 degrees C) Fe-As-sulfide rich stage that produced the arsenopyrite- and pyrite-dominated polymetallic massive veins, and 2) a later lower temperature stage (T = 160 to 300 degrees C) characterized by the formation of Bi-sulfosalts and tellurides in the polymetallic quartz and quartz-pyrite veins. It is suggested that the gold-polymetallic mineralization at Kolchiko was developed under regional retrograde greenschist facies metamorphism and was structurally controlled by the onset of the late Oligocene to early Miocene dextral strike-slip fault zone, which is documented along the western edge of the Vertiskos Unit.

Deep-sea Fe-Mn polymetallic nodules formed nowadays at the deep-sea ocean floor were evaluated as promising critical raw materials (CRMs). Here, we report results of polymetallic nodules from the H22_NE block of the Interoceanmetal (IOM) exploration area in the eastern part of the Clarion–Clipperton Zone (CCZ), NE Pacific Ocean. The polymetallic nodules were studied with X-ray Diffraction, Raman spectroscopy, SEM-EDS, and LA-ICP-MS (bulk nodules and in situ nodule layers). Additionally, we combine geochemical data of polymetallic nodules with the previously reported data of pore waters and sediments from six stations. Our study aims to define the mineral composition and determine the content of CRMs in the polymetallic nodules and to assess the main factors controlling metal deposition and nodule enrichment in some CRMs. Mn content and the Mn/Fe ratio of the nodules classify them mostly as mixed hydrogenetic–diagenetic type. They are also enriched in Ni, Cu, Co, Zn, Mo, W, Li, Tl, and REE. The in situ REE patterns exhibit MREE and HREE enrichment and a variable Ce anomaly that argues for a changing oxic/suboxic environment and periodically changing of diagenetic and hydrogenetic nodule growth. The results of the joint study of the bottom sediments, pore waters, and polymetallic nodules show a complexity of processes that influence the formation of these deposits. The changing oxic and anoxic conditions are well documented in the chemistry of the nodule layers. Probably the most important controlling factors are sedimentation rate, bioturbation, adsorption, desorption, and oxidation. In addition, growth rates, water depth variations, electro-chemical speciation, phosphatization, and the structures of the Fe-Mn adsorbents are also considered. The polymetallic nodule deposits in the IOM contract area are estimated for future mining for Ni, Cu, Co, and Mn resources. They, however, contain additional metals of economic importance, such as REE and other trace elements (referred to as CRMs) that are potential by-products for metal mining. They can significantly increase the economic importance of exploited polymetallic nodules.

The sulfur isotope compositions of three generations of pyrite originated from skarns, stockwork, and late-stage, post-hydrothermal veins from three various zones of the porphyry style Myszków Mo–Cu–W deposit (center, circum-deposit, and periphery) were investigated as a proxy for the mineralized core of porphyry system. Overall, the mode of δ 34 S pyrite decreases with time, from skarn- through main- up to late-stage of ore mineralization (with average values of + 6.13, + 5.65, and + 3.34 ‰, respectively). The gradual decrease in δ 34 S values outwards from the deposit core (av. 3.95 ‰), through circum-deposit (av. + 3.40‰) to distal zone (av. + 3.05 ‰) was detected only for late-stage pyrite. Both the temporal and lateral zonation of δ 34 S pyrite could be explained by the progressive temperature decrease of the mineralized system and the mixing of ore-forming solutions with more dilute meteoric waters. The trace geochemistry of late-stage pyrite shows relatively constant values of Tl (from 0.13 to 0.14 ppm), Ti (9.10–10.30 ppm), Cr (9.94–12.37 ppm), and Mn (6.94–7.59 ppm) regardless of the zone of the Myszków Mo–Cu–W deposit. While, As (24.96–184.80 ppm), Sb (0.50–13.52 ppm), Bi (0.57–1.54 ppm) in pyrite and Sb/Te (0.06–1.62), Co/Bi (3.32–34.23), and Ag/Ni (0.006–0.140) increase with the proximity to the ore, contrary to Ag/Co which rises towards the periphery of the deposit (0.04–0.13). Ultimately, these results indicate that sulfur isotope data supported by trace geochemistry of late-stage pyrite can be potentially used as vectoring proxies to predict the likely direction to the mineralized center of a porphyry system.

The mineral and chemical composition of graphite and graphite-bearing marbles from the Vacha, Ardino–Nedelino, and Chernichevo–Boturche areas was studied. The minerals identified by X-ray diffraction in different marble samples are calcite, dolomite, pargasite, chondrodite, quartz, and graphite. The presence of accessory minerals, such as apatite, rutile, zircon, Fe sulfides, Ag-Pb-Sb, Pb-Bi, Ag-Sb phases, etc was confirmed by LA-ICP-MS. Among the analyzed 58 elements in the marbles, only Mo, Sr, Bi, Pt, Ag, and Sb have contents that exceed at least twice the Clarke values for metamorphosed carbonate rocks. The graphite concentrate contains micron-sized phases of Mo-S, Cu, Fe, and others. The contents of 26 elements were measured by INAA in graphite. Uranium, As, Zn, Th, Sb, and Sm have several times higher concentrations compared to the content in the original graphite-bearing marble.

The contents of 49 trace elements in sub-bituminous Pernik coals and their waste products from preparation and combustion processes were investigated. The studied coals have trace element contents higher than the respective Clarke values for brown coals and some of them may pose environmental concerns. The elements Li, Rb, Cs, Ba, Sc, Y, La, Ce, Nd, Sm, Eu, Er, Ga, Zr, Sn, V, Nb, Ta, W, F, Cu, Zn, In, Pb, Cr, Co, Ni, and Th in the feed coals have concentrations that exceed twice the Clarke values. Most element contents in bottom ash are enriched compared with those in feed coal. Some of the volatile elements are equal or significantly depleted including Sn, Mo, Sb, F, Bi, Cd, Ge, and Pb. Fly ash has higher contents of Ga, Zr, Hf, Sn, V, Nb, Mo, and F in comparison with bottom ash. Most elements have a significant positive correlation with ash yield, indicating their inorganic association. The mixed wastes (coal slurry, bottom ash, and fly ash) in the disposal pond are slightly depleted of most of the elements studied with the exclusion of Cl, Ba, and Br. The Pernik coals and their waste products are unpromising for the extraction of REY due to their low element contents.

Mercury contents in two types of Pernik coals and in mixed waste from coal preparation and combustion from a disposal pond were measured using direct mercury analyzer. Pearson correlation coefficients between Hg concentrations and ash content among different types of samples are statistically insignificant, suggesting predominantly organic affinity of Hg. The Hg content of 150 ppb in the fuel for the thermoelectric power station (low grade coal) slightly exceeds the world average for brown coals (100 ppb). Mercury concentrations in the mixed waste are twice lower than those in low grade coal, suggesting that Hg is released into the atmosphere during coal processing. However, coal for indoor heating (high grade coal) is significantly enriched in Hg (average of 392 ppb) and, therefore, its residential use as fuel may release larger amounts of Hg to the atmosphere. Newly formed gypsum from the disposal pond concentrates Hg (221 ppb).

Assarel porphyry copper deposit is located in the Panagyurishte ore district, Central Srednogorie, which is a part of the Late Cretaceous Apuseni-Banat-Timok-Srednogorie magmatic and metallogenic belt. This study reports a new data on the epithermal high-sulfidation ore mineralization described previously as "specific" and "rare". The ore mineralization is associated with advanced argillic alteration and is represented by enargite, colusite, sulvanite, bornite. They occur as thin veinlets brecciating or crosscutting earlier small disseminated euhedral/subhedral to anhedral pyrite in quartz or subhedral/anhedral pyrite nest-like aggregates with zunyite, gypsum, rutile. Bornite is replaced by chalcocite and covellite, and enargite by covellite. Enargite contains Sn, Sb, Te, while colusite occurs as two distinct chemical varieties: 1) Sn-rich and Mo-bearing, with lower As content, and 2) Sn-poor, Ge-bearing, As-rich. Both varieties have 0.1-0.2 wt% Sb. Bornite and chalcocite contain small amounts of Se. Pyrite spatially associated with this mineralization is enriched in Cu, Co, and Ni, with Co/Ni and Co/As >= 2.

This work presents a mineralogical and geochemical study of sulfide ores from the epithermal listvenite-associated Badovc Pb-Zn-Sb-Ni deposit, which is located in the central part of the Kizhnica-Hajvalia-Badovc ore field, in the Trepca Mineral Belt (TMB) in Kosovo. Badovc is an example of one of many base-metal Pb-Zn-Ag deposits associated with the Serbo-Macedonian metallogenic province. There are three types of ores, the first two associated with polymetallic epithermal IS veins (massive-banded Pb-Zn-Sb and rhodochrosite-stibnite breccia) and disseminated ores associated with listvenites, which are hydrothermally altered mafic and ultramafic rocks. The mineralogy of these ores was described using EPMA in combination with reflected and transmitted light microscopy. The mineralogy of massive-banded Pb-Zn-Sb and rhodochrosite-stibnite breccia ores is relatively limited: sphalerite + rhodochrosite-siderite + pyrite/marcasite +/- Pb-Sb sul-fosalts +/- stibnite. Listvenite Pb-Zn-Sb-Ni ores are more mineralogically variable due to the multi-stage for-mation of these rocks and the overprint of polymetallic mineralization. Apart from typical base-metal sulfides such as sphalerite, pyrite, galena, and chalcopyrite, the listvenite ores contain Fe-Mn carbonates, quartz, and Ni-Fe +/- As +/- Sb association (gersdorffite, ullmannite, millerite, and Ni-Fe thiospinels), Sn minerals (stannite and cassiterite). The LA-ICP-MS technique was used to determine critical metals occurring as minor and trace elements and substitution mechanisms in sphalerite, pyrite, stibnite, chalcopyrite and stibnite. The main critical metals, such as In, Sn, Ga, and Ge, are hosted by sphalerite in all types of ores. The highest concentrations of tin in sphalerite are observed in massive-banded Pb-Zn-Sb ores, which substitutes within the 3Zn2+ <-> 2(Cu, Ag)+ + Sn4+ mechanism. The highest concentrations of indium are observed in sphalerites from listvenites, indicating the 2Zn2+ <-> Cu+ + In3+ substitution. Low-temperature sphalerites from rhodochrosite-stibnite breccia exhibit elevated concentrations of Ga, Ge, and Ag, which incorporate into the structure through 2Zn2+ <-> (Ag, Cu)+ + Ga3+, and 3Zn2+ <-> 2(Cu, Ag)+ + Ge4+ mechanisms. The specific crystallization temperatures using GGIMFis for sphalerite are: 248-332 degrees C for massive-banded Pb-Zn-Sb ores, 208 degrees C for rhodochrosite-stibnite breccia, and 2112-344 degrees C for listvenite Pb-Zn-Sb-Ni ores. Additionally, stibnite from Badovc exhibits substitutions such as As3+ <-> Sb3+ and (Cu+ + Ag+) + Pb2+ <-> Sb3++ , and can incorporate various monovalent elements other than copper, including Ag+ and Tl+. Studies of epithermal listvenite-associated Badovc Pb-Zn-Sb-Ni deposits suggest that similar deposits spread across the Balkans may hold considerable prospectivity.

Garnet granulite xenoliths from the Nurbinskaya diatreme in the central part of the Archean Anabar province in Siberia are fragments of the local lower crust that experienced multiple metamorphic events in the Paleoproterozoic and reheating events in the Mesoproterozoic and later. This study addresses the timing of metamorphic transformations, and constrains the cooling rate and the time of stabilization of the lower crust. The observed metamorphic mineral assemblage of garnet, clinopyroxene, plagioclase, amphibole, rutile and ilmenite was formed at 800 °C, 1.1–1.2 GPa under water-undersaturated conditions at 1.88 Ga. However, the mineral assemblage is not well equilibrated and retains evidence of earlier and subsequent metamorphic stages. Late titanite formed in response to hydrous fluid influx according to phase equilibria modeling. U-Pb dating shows two events of titanite formation at 1850 ± 5 Ma and at 1788 ± 2 Ma. After deformation, which led to the porphyroclastic rock textures, the granulites underwent near-isobaric cooling. The cooling rate was higher than 6 °C/Myr, to retain the garnet compositional zoning. Rutile ages are discordant, with 207Pb/206Pb dates ranging from 1.43 to 1.53 Ga. However, rutile may have responded to earlier thermal pulses, and was also reset later, so it does not record the stabilization of the crust. Crustal stabilization after Paleoproterozoic orogenic events may have occurred shortly after titanite formation.

The migration of 32 elements from natural zeolitized tuffs from the Beli Plast and Golobradovo deposits (Bulgaria) was determined in ultrapure, tap, mineral, and coal mine waters in order to evaluate their desorption and adsorption properties. The tuffs are Ca-K-Na and contain clinoptilolite (90 and 78wt.%, respectively), plagioclase, sanidine, opal-CT, mica, quartz, montmorillonite, goethite, calcite, ankerite, apatite, and monazite. The desorption properties are best revealed during the treatment of ultrapure, tap, and mineral water, whereas the adsorption properties are best manifested in coal mine water treatment. The concentrations of Al, Si, Fe, Na, Mn, F, K, Pb, and U increase in the treated ultrapure, tap, and mineral water, while the content of K, Be, Pb, and F increase in the treated mine water. The tuffs show selective partial or complete adsorption of Na, Mg, Sr, Li, Be, Mn, Fe, Co, Ni, Cu, Zn, Al, Pb, U, and SO42−. They demonstrate the ability to neutralize acidic and alkaline pH. Sources of F are presumed to be clinoptilolite and montmorillonite. The usage of zeolitized tuffs for at-home drinking water treatment has to be performed with caution due to the migration of potentially toxic and toxic elements.

The geochemical characteristics of pore waters, bottom sediments and polymetallic nodules from the Interoceanmetal exploration area in the eastern part of the Clarion-Clipperton Fractures Zone (CCZ), NE Pacific were studied. Manganese has a positive correlation with Fe in pore waters but a negative correlation in the sediments and polymetallic nodules. The results suggest that Mn precipitates faster than Fe in sediments and especially in nodules that are enriched in Mn, Ni and Cu compared to the host sediments. PAAS-normalized REE patterns of pore water layers, sediments layers, bulk nodules and nodule growth layers show gradual enrichment resulting of several factors, including low sedimentation rate, high REE of the bottom seawater, oxidation conditions, certain bottom current conditions and the presence of Fe-Mn oxyhydroxides.

The chemical composition and trace element concentration in stibnite from the Kizhnica-Hajvalia-Badovc (KHB) ore field (Kosovo) was studied. Trace element measurements in stibnite from 2 localities (Janjevo stibnite-quartz vein and Badovc stibnite-rhodochrosite breccia) were conducted using LA-ICP-MS technique. In addition to the typical enrichments in As, Pb, Hg, or Cu known from the literature, stibnite from the KHB ore field shows the highest known concentrations of Tl (up to 213 ppm) and Ag (up to 146 ppm). In addition, elevated concentrations of As (up to 4,100 ppm), Pb (up to 2,000 ppm), Hg (up to 316 ppm), and Cu (up to 46.9 ppm) are observed. The following three independent mechanisms of incorporation of the above-mentioned trace elements into the stibnite structure are presented: (1) As3+ <-> Sb3+; (2) (Cu+ + Ag+) + Pb2+ <-> Sb3+ +square; and (3) Tl+ + Hg2+ <-> Sb3+ +square.

This work presents a mineralogical and geochemical study of Cu-Bi-Ag & PLUSMN; W ores from Janjevo in the Trepca Mineral Belt in Kosovo. This locality indicates a new type of Bi-Cu & PLUSMN; Au mineralization within the Kizhnica-Hajvalia-Badovc ore field, including Cu-Bi & PLUSMN; Ag & PLUSMN; As sulfosalts paragenesis previously not described in Kosovo and in this part of the als, as well as their paragenetic relationships and the distribution of minor and trace elements in main ore minerals, are discussed based on microscopy, microprobe, and laser ablation inductively coupled plasma mass spectrometry studies. The Cu-Bi-Ag & PLUSMN; W hydrothermal mineralization in Janjevo was formed during four stages: (1) Early base metal stage, (2) Bismuth stage, (3) Main stage, and (4) Late stage. The Early base metal stage is represented by pyrite, sphalerite I, chalcopyrite I, galena I, bournonite I, tetrahedrite I, siderite, and quartz. The Bismuth stage includes arsenopyrite I, lollingite, native bismuth, galena II, chalcopyrite II, tetrahedrite II, quartz, siderite, and Bi-Pb & PLUSMN; Cu & PLUSMN; Ag sulfosalts: bismuthinite, aikinite, krupkaite, cosalite, and gustavite. The Main stage is represented by chalcopyrite III, tetrahedrite group minerals (tetrahedrite and tennantite) III, galena III, sphalerite II, arsenopyrite II, bournonite II, and siderite. The Cu-Bi & PLUSMN; Ag & PLUSMN; As sulfosalts (pearceite, cupropearceite, wittichenite, and an unknown phase: AgCuBiS3) associated with galena IV, siderite, and quartz were formed in the final low-temperature Late stage. The application of GGIMFis geothermometry on sphalerite gives the following sphalerite precipitation temperatures: 220-272 & DEG;C for sphalerite I and 160-190 & DEG;C for sphalerite II. Presented results show that in addition to numerous Bi sulfosalts in Janjevo Cu-Bi-Ag & PLUSMN;W ores, bismuth has been incorporated into base metal sulfides, as well as arsenopyrite. The main carrier of bismuth is arsenopyrite I, which has started the crystallization of the bismuth stage.

Pyrite and marcasite aggregates were found in a sample of blue silty clay from an exploration drill core at the northern edge of the Troyanovo North mine, Maritsa East lignite basin, Bulgaria. The aggregates have various sizes – from 50 µm (single crystal twins) to 0.5 cm (large twinned aggregates). Pyrite occurs as single cubic and cuboctahedral crystals, penetrative twins forming oval-shaped aggregates with visible cubic to truncated octahedral habits. Marcasite occurs as single tabular, pyramidal crystals, but often as twinned (penetrative, parallel, contact) composite oval-shaped aggregates. Marcasite has higher trace element contents than pyrite. In both minerals are detected Mn, Co, Ni, Cu, Zn, Mo, As, Sb, Hg, Tl and Pb with varying contents. The crystal aggregate growth is slow in varied supersaturation and pH due to the occurrence of both octahedral and cubic faces in pyrite and marcasite presence.

The contents of major and rare elements in 10 samples of altered (mainly zeolitized) pyroclastic rocks from the Eastern Rhodopes are investigated. The samples are selected to represent different secondary mineral associations specific to the area. The obtained results indicate that the diversity in secondary mineral associations has relatively little influence on the trace element geochemistry of zeolitized pyroclastic rocks in the Eastern Rhodopes. Regarding their trace and rare earth element composition, these rocks show the main characteristics seen in the acid lavas in the area.

The chemical composition and trace element concentration in sphalerite from the Kizhnica deposit, Hajvalia-Badovc ore field, central Kosovo, was studied. Sphalerite was investigated from seven occurrences: Kizhnica quarry Cu-Bi epithermal veinlets; Janjevo polymetallic veinlets; Janjevo Cu-Bi-Ag(W) contact-metasomatic type; Janjevo Sb-As-Tl-Hg lithologically controlled type; Badovc Pb-Zn-Sb(Ni) listvenite hosted; Pb-Zn-Sb banded vein-type; and Sb vein type. Different concentrations of individual trace elements are observed in three main systems: Pb-Zn-Ag, Bi-Cu +/- Au and Sb-As-Tl. The presence of high concentrations of trace elements such as In, Sn, Sb, Tl and Ag is observed at specific localities. The results allow estimation of formation temperature using the GGIMF in sphalerite geothermometer.

The concentrations of trace elements in sphalerite from blocks 7, 700 and 149-south of the copper-gold high (to intermediate) sulphidation Chelopech deposit were determined by LA-ICP-MS. Their average contents in ppm based on 27 analyses are: Cu (2124) > Fe (4166) > Cd (1302) > Pb (504) > Sb (460) > Mn (439) > As (337) > Ga (173) > Ge (152) > Ag (143) > Hg (97) > In (37) > Tl (33) > Se (25) > Ti (15) > Mo (12) > Sn (7) > Te, Au (6) > V (5) > Pd (4) > Bi (3) > W (1) > Co (0.3).