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The beryllium silicate minerals phenakite and bertrandite have been identified in granitic pegmatite dykes of the beryl-columbite subtype of Variscan age (~340−355 Ma), associated with S- to I-type granitic rocks of the Tatric Superunit, Western Carpathians (Slovakia). The two beryllium silicates and associated minerals were characterised by electron microprobe analysis, back-scattered electron petrography and cathodoluminescence imagery, X-ray diffraction and micro-Raman techniques. Phenakite and bertrandite form euhedral-to-anhedral crystals and aggregates in irregular domains and veinlets replacing primary magmatic beryl. A detailed textural study revealed a close genetic association of phenakite and bertrandite with secondary fine-grained quartz, K-feldspar and muscovite. Locally, clay phyllosilicate minerals, (with compositions similar to those of Fe-dominant hydrobiotite, beidellite, nontronite and saponite) occur as the youngest minerals. During the post-magmatic (hydrothermal) stage of the pegmatites, infiltration of aqueous K-bearing fluids at T ≈ 200–400°C resulted in the breakdown of magmatic beryl to secondary assemblages containing phenakite and bertrandite.

This paper describes a newly discovered Bi-Cu±Au mineralization co-occurring with Pb-Zn-Ag hydrothermal mineralization within the Kizhnica-Hajvalia-Badovc ore field, central Kosovo, Vardar Zone. The mineralogy of two styles of Bi-Cu±Au mineralization was described using EPMA in combination with reflected and transmitted light microscopy. Hydrothermal Cu-Bi veinlets in the Kizhnica andesite quarry consist of Bi sulfosalts (bismuthinite, cosalite, aikinite, and krupkaite), pyrite, hematite, chalcopyrite, galena, sphalerite, and tetrahedrite group minerals. Disseminated Bi-Au-Cu-Te mineralization from the contact type of mineralization (hornfels) consists of Bi sulfosalts (cannizzarite, bismuthinite, galenobismutite, cosalite), associated with sulfarsenides (arsenopyrite, gersdorffite, and cobaltite), base metal sulfides (chalcopyrite, pyrite, sphalerite, pyrrhotite, and galena), native gold, native bismuth, and tetradymite. LA-ICP-MS analyses of sphalerite, chalcopyrite, and tetrahedrite indicate increased content of In and Sn in the Kizhnica Bi-Cu-Au mineralizing system, while LA-ICP-MS analyses in pyrites show the presence of many elements, e.g., Au, As, Co, Sb, Tl, Hg, Pb, Bi related to the structure of pyrite or controlled by nano-inclusions. The results suggest a connection between Bi-Cu±Au mineralization and the proximity to intrusive rocks, which may be helpful for Au exploration in Kosovo.

The sediment-hosted As-Sb-Tl-Pb +/- Hg +/- Au Janjevo occurrence is located in the southern part of the KizhnicaHajvalia-Badovc ore field, in the Trepca (Trepca) Mineral Belt (TMB) in Kosovo. The As-Sb-Tl-Pb +/- Hg +/- Au mineralization is hosted by Upper Triassic marbles and occurs in the form of quartz-stibnite veins and dolomitized irregular pockets associated with jasperoid rocks. The main sulfide most widespread in the mineralization studied is pyrite which is the main carrier of thallium. A wide range of techniques was used to characterize the geochemistry and textural evolution of pyrite/marcasite from Janjevo: polarized reflected-light microscopy, electron microprobe (EPMA), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), X-ray powder diffraction (XRPD), MOssbauer spectroscopy, and isotopic studies. The study of 42 thin and polished sections resulted in the identification of 4 generations of pyrite/marcasite. The first generation of pyrite related to the pre-ore stage occurs as framboidal pyrite with different degrees of evolution (Py1a), as well as recrystallized pyrite/marcasite (Py1b). Au-enriched pyrite (Py2) occurs as elongated fibrous aggregates and is genetically associated with the formation of stibnite veins (Sb stage). As-Tl-Sb-Hg pyrite (Py3) forms irregular colloform aggregates which fill the stylolites and also overgrow older generations of pyrite. The youngest generation is represented by marcasite (Py4), which forms euhedral crystals. Co/Ni ratio < 1 in all pyrite/marcasite generations implies a sedimentary fingerprint. On the other hand, delta S-34 isotopic studies confirm a magmatic sulfur source for As-Tl-Sb-Hg pyrite (Py3), as well as co-occurring stibnite and realgar. The most important minor and trace elements in pyrite/marcasite are As (up to 14.1 %), Tl (up to 3.94 %), Sb (up to 3.73 %), and Hg (up to 0.55 %), which are mainly hosted by Py3. In addition to arsenic, thallium, antimony, and mercury, other generations of pyrite show enrichment in Ni, Co, and Cu (framboidal pyrite Py1), Au, and Se (Au-enriched pyrite Py2), and Se (marcasite Py4). The highest gold content of up to 6.08 ppm was recorded at Py2. Studies on Py3 geochemistry confirm the presence of 2Fe(2+) Tl+ + Sb3+ heterovalent substitution in pyrite. As-Tl-Sb-Hg pyrite (Py3) is the main thallium host mineral in the mineralization studied, with significantly less thallium present in the Pb-Sb +/- Tl +/- As sulfosalts. In addition, the high arsenic content of Py3 is due to the presence of arsenic in the form of As1- and As-0 related to amorphous arsenic-rich nanoparticles. The reported Py3 is the best phenomenon of the crystallization of colloform As-Tl-Sb-Hg-rich pyrite under hydrothermal conditions. Pyrite-rich sediment-hosted As-Sb-Tl-Pb +/- Hg +/- Au mineralization from Janjevo is associated with the distal manifestation of a concealed porphyry system.

Mineralogical and geochemical characteristics of amber deposits located in the Dominican Republic, i.e., Hato Mayor Province of the Eastern Mining District (EMD) in the Cordillera Oriental, and Santiago Province of the Northern Mining District (NMD) in the Cordillera Septentrional were performed. The results of analyses of amber-bearing sediments collected from the borehole in Siete Cañadas area (EMD) were referenced to the petrological data obtained for the coaly shales from La Cumbre (NMD). The mineralogy of the rocks was described using transmitted and reflected light microscopy, scanning electron microscopy, Powder X-ray diffraction and Fourier Transform Raman Spectroscopy. Biomarker analyses by the gas chromatography-mass spectrometry were used to trace the genetic source and transformation stage of abundant organic matter hosted in the core sediments. Our findings indicated that basins in EMD and NMD regions were different isolated palaeosettings, in which under the influence of local physicochemical factors the terrigenous material was transformed and got maturated. In both amber deposits, the sedimentation of clastic and organic material proceeded in the presence of marine conditions. In case of the NMD area, the sedimentation underwent probably in the conditions of the lagoon environment, a shallow maritime lake or periodically flooded plain, that facilitated organic matter decomposition and carbonation from meta-lignite to sub-bituminous coal (random reflectance of coal - Rro = 0,39%). In the EMD region, the sedimentation took place in a deeper basin, where terrigenous material was likely mixed with material found in situ (fauna fossils, carbonate-group minerals) to form the mudstones enriched in bituminous substance of low maturity. The organic matter found in the rocks from both regions is of mixed terrestrial/marine origin and was deposited in the presence of low oxygen concentration and reducing and/or dysoxic conditions.

Primary ore mineralization in the abandoned Boguszów baryte-polymetallic deposit, located in the Intra-Sudetic Depression, was studied by reflected light microscopy and electron microprobe. Ore minerals, occurring as veinlets, irregular aggregates and lenses in baryte veins are hosted by the Upper Carboniferous Chełmiec rhyodacite laccolith. They are dominated by galena, sphalerite (with Cd up to 0.04 apfu) and tetrahedrite group minerals (TGM). Four generations of the TGM were distinguished according to textural features and Ag content: (1) low-Ag tetrahedrite-(Zn) (Ag: 0.22–0.6 apfu), (2) Ag-enriched tetrahedrite-(Zn) and Ag-enriched tetrahedrite-(Fe) (Ag: 0.71–1.45 apfu), (3) members of the freibergite series: “freibergite-(Fe)” and “freibergite-(Zn)” (Ag: 3.21–3.48 apfu; Hg: up to 0.75 apfu), (4) member of the “freibergite-(Fe)” series (Ag: 5.32–5.78 apfu). Several elongated inclusions of Ag-bearing sulphosalts within galena crystals were observed (members of the series “freibergite-(Fe)” and “freibergite-(Zn)”, pyrargyrite and polybasite). These polymetallic silver-bearing ores were mined in Boguszów from the 15th to the 19th century. Additionally, small grains of cobalt-enriched löllingite and gersdorffite were observed, which were formed from fluids sourced from the ultramafic basement. The textural characteristics of the ore, the mineral paragenesis and the chemical composition of individual ore minerals indicate low-temperature crystallization conditions.

Agate samples collected from the vicinity of Asni and Agouim (Western Atlas, Morocco) were investigated using microscopic observations supported by Raman micro-spectroscopy. The agates are marked by the presence of various microtextures typical of epithermal vein deposits, including jigsaw-puzzle, feathery, and lattice-bladed. The first two indicate that the formation of agates was likely marked by recrystallization of metastable silica phases (i.e., opaline silica or massive chalcedony). The presence of lattice-bladed (after barite and calcite) quartz may be, in turn, ascribed to the boiling-related conditions that could have triggered the formation of abundant copper and iron sulfides found within silica matrix. Additionally, the local occurrence of growth lines (so-called Bambauer quartz) and intergrowth of length-slow and length-fast chalcedony are linked to the variations of physico-chemical conditions during rock formation (alkaline-acidic). According to Raman spectroscopy, silica matrix of the agates is made of &alpha, quartz with a local admixture of moganite (from 0.0 up to 78 wt.%), but also contains numerous solid inclusions of hematite, celadonite, as well as poorly-organized carbonaceous material and rutile. These phases were likely emplaced during low-temperature hydrothermal activity of SiO2-bearing fluids that originated from post-magmatic hydrothermal activity developed within host rocks and/or meteoric waters.

Unique association of sulphosalts was discovered at the Kl’ačianka occurrence, Nízke Tatry Mts., Slovak Republic. It is bound to thin hydrothermal veins with Sb mineralization hosted by the Variscan muscovite-biotite granodiorite and granite of Prašivá type. Ore mineralogy and crystal chemistry of ore minerals are studied here by ore microscopy, X-ray powder diffraction, electron microprobe analyses, and Raman spectroscopy. The early ore mineralization composed of pyrite and arsenopyrite is hosted in quartz gangue and is followed by abundant association of sulfos-alts. Stibnite, zinkenite, robinsonite (including Cu-bearing variety), jamesonite, scainiite, dadsonite, disulfodadsonite, rouxelite, chovanite, semseyite, boulangerite, geocronite, tintinaite (with low Bi contents), tetrahedrite-(Fe), tetrahedrite-(Zn), bournonite, chalcostibite, bismuthinite, and gladite in association with sphalerite and rare galena and gold are identified here. The chlorine-rich character of the described sulphosalt association is its characteristic phenomenon. It is represented not only by the occurrence of Cl-sulphosalt and dadsonite, but increased Cl contents were detected in boulan-gerite, chovanite, disulfodadsonite, robinsonite, rouxelite, scainiite, or tintinaite. The presence of oxygen-containing sulphosalts, such as rouxelite, scainiite and chovanite, is also interesting. The crys-tallization of these rare chloro-, oxy-and oxy-chloro-sulphosalts at the Kl’ačianka occurrence required very specific conditions (elevated O2 /S2 fugacity) and high chlorine activity in ore-forming fluids.

New mineralogical and mineral-chemical data from the Stan Terg deposit, Kosovo, revealed the presence of abundant Bi-sulphotellurides associated with Bi- and Sb-sulphosalts and galena in pyrite–pyrrhotite-rich skarn-free ore bodies (ores without skarn minerals). The Bi-bearing association comprises Bi-sulphotellurides (joséite-A, joséite-B, unnamed phase A with a chemical formula close to (Bi,Pb)2(TeS)2, unnamed phase B with a chemical composition close to (Bi,Pb)2.5Te1.5S1.5), ikunolite, cosalite, Sb-lillianite, members of the kobellite series and Bi-jamesonite. Compositional trends of the Bi-sulphotellurides suggest lattice-scale incorporation of Bi–(Pb)-rich module and/or admixture with submicroscopic PbS layers in modulated structures, or complicated Bi–Te substitution. Cosalite is characterized by high Sb (max. 3.94 apfu), and low Cu and Ag (up to 0.72 apfu of Cu+Ag). Jamesonite from this mineralization has elevated Bi content, from 0.85 to 2.30 apfu. The negligible content of Au and Ag in the Bi-sulphotellurides, the low content of Ag in Bi-sulphosalts, together with the lack of Au–Ag bearing phases in the mineralization, indicate either ore deposition from fluid(s) depleted in precious metals, or physico-chemical conditions of ore formation preventing Au and Ag precipitation at the deposit site. The temperature of initial mineralization may have exceeded 400 °C as suggested by the lamellar exsolution textures observed in lillianite, which indicate breakdown textures from decomposition of high-temperature initial crystals. Non-stoichiometric phases among the Bi-sulphosalts and sulphotellurides studied at Stan Terg reflect modulated growth processes in a metasomatic environment.

The presence of botallackite was recognized in an underground galery in the Polkowice-Sieroszowice copper mine. This mineral coexists with paratacamite, clinoatacamite, gypsum and halite. Botallackite crystallized from chloride-reach (3500 mg/dm3), warm (33°C) mine water. On the basis of microprobe analyzes, two types of botallackite were recognized. The first one contains only small amounts of Pb, Fe and Zn. These elements substitute Cu2+ ions in small proportions. Empirical formula of this botallackite is: (Cu1.94Pb0.02Fe0.02Zn0.02)S = 2.00Cl0.98(OH)3.02. The second type of the mineral were characterized by increased amounts of Pb, Fe, Zn. The empiric formula of this type of botallackite can be expressed as: (Cu1.85Pb0.09Fe0.04Zn0.02)S = 2.00Cl1.05(OH)2.95. The calculated unit-cell parameters of botallackite from Polkowice-Sieroszowice mine are as follows: a = 5.7165(2), b = 6.1362(2), c = 5.6325(2), b = 92.943(3). Botallackite is a least stable polymorph of Cu2Cl(OH)3 and finally transforms to more stable polymorphs. The botallackite recrystallization can be inhibit by high concentration of Ca2+ in the mine water. Substitution of Cu2+ ions by other divalent cations can slows the rapidity of recrystalization this mineral and prevent its further transformation also. The Polkowice-Sieroszowice mine is the first occurrence of botallackite in Poland.

This contribution reviews and affords new insights into the crystal chemistry of gadolinite-datolite group (GDG) silicates by re-examination of published and unpublished analytical data. More than 200 electron microprobe analyses (EMPA) and data from both single-crystal and powder X-ray diffraction of 53 samples of GDG silicates were collected to study site occupancy effects on local and long-distance geometry of the crystal structure. Results were achieved by statistical analysis and bond-length and bond-angle calculations. Here, crystal-structure geometry and site occupancy dependence is manifested in the GDG chemical composition and lattice parameters. While the substitution of B for Be at the tetrahedral Z site has the greatest impact on the size of the a parameter, variations in W -site occupancy result in a change in the size of the b parameter. Moreover, the degree of variability in the occupancy of the W site appears to influence the layer-stacking order, which differs between well ordered datolite and weakly ordered gadolinite-subgroup (GSG) minerals. This is documented by c parameter variability. The relationship between the X -site occupancy and lattice parameters is explained by the Jahn-Teller effect, which induces bond-length and angular distortion of the X O 6 octahedron. In addition, the structural arrangement of the X site excludes large cation (such as Ca, Bi, and REE) occupancy without any significant impact on the size of the X O 6 octahedron. Consequently, the formula for minasgeraisite-(Y) with the originally proposed Ca occupancy of the X site is questionable, since no significant difference from hingganite lattice parameters was observed. Thus the mineral requires further structural refinement. The structural arrangement of GDG silicates suggests that two dominant substitution vectors control their chemical composition: CaB(REE) −1 Be −1 and Fe 2+ O 2 (OH) −2 . However, both substitutions are more widespread in GSG minerals than in datolite subgroup (DSG) minerals. This may result from different geochemical properties of their genetic environment. However, there can be structural factors concerning X , W , and Z site occupancy which differentiate the far more chemically variable GSG from DSG.

Agate nodules from Kerrouchen (Khenifra Province, Meknes-Tafilalet Region) in Morocco occur in Triassic basalts and reach up to 30 cm in diameter. Monocentric, banded agates—mainly in pastel pink, grey, white and yellow—with infiltration canals (osculum) are observed. Raman microspectroscopy revealed that the agates mainly consist of low quartz and subordinately moganite with distinctive 460 and 501 cm−1 marker bands, respectively. Linear mapping indicated that moganite mainly concentrates in grey zones of the monocentric agate nodules. The other types, polycentric and pseudostalactitic agates, are usually brown and red and contain minerals such as hematite and goethite. They form both regular and irregular mosaics rich in ornamentation. Occasionally, aggregates of copper sulphides or titanium oxides (rutile) can also be observed. These minerals are sometimes accompanied by carbonaceous material marked by 1320 and 1585 cm−1 Raman bands. It seems that formation of agates from Kerrouchen was induced by Si-rich and Fe-moderate fluids. Copper sulphides, rutile, and carbonates (possibly calcite) were most likely incorporated during post-magmatic processes. The origin of solid bitumen can be the result of hydrothermal or hypergenic processes.

Stannite group minerals (ferrokësterite and stannite) occur in small amounts in association with sulfides in hydrothermal Pb-Zn deposits in Kosovo. The chemical composition of sphalerite co-existing with Sn-bearing minerals has been investigated using laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS). Flat Sn-spectra suggest that Sn is bound in the sphalerite lattice or as nanoincluions. Sphalerite from Stan Terg, overgrown by ferrokësterite, contains the lowest Sn content (few ppm) and have been precipitated before Sn-enrichment in the fluids. The highest value of Sn (520 ppm) of Stan Terg sphalerite was obtained directly close to the ferrokësterite rim, and indicates a rapid increase of Sn in the hydrothermal fluids. Significantly higher values of Sn in sphalerite were obtained from other deposits: 1600 ppm (Artana), up to 663 ppm (Kizhnica), up to 2800 ppm (Drazhnje). Stannite-sphalerite geothermometry revealed the following ore-forming temperatures for the Kosovo mineralization: 240–390 °C for Stan Terg, 240–370 °C for Artana, >340 °C for Kizhnica, and 245–295 °C for Drazhnje. Sphalerite and stannite group minerals precipitated simultaneously during cooling from reduced hydrothermal fluids and under low-sulfidation fluid states. Fluctuations in physico-chemical fluid conditions are evidenced by the presence of stannite group minerals along growth zones in sphalerite and may be related to short interval of magmatic pulses during ore deposition.

Chovanite, a new representative of the group of oxysulphosalts of Pb and Sb was found in three hydrothermal deposits of antimony ore, Dubrava, Male ´ ˇ Zelezne ´, and Klacianka, situated on the northern slopes of the Low Tatra Mountains, Slovakia. It is associated with other Pb-Sb sulphosalts, especially boulangerite, robinsonite and dadsonite. In reflected light, chovanite is white, bireflectance is distinct already in air. Pleochroism is present; colour varies from white with a yellowish green tint (darkest position) to white with a faint bluish tint (lightest position). Reflectance values in air are Rmax -R min (%) (l nm): 43.6-37.7 (470), 43.0-36.7 (546), 41.3-35.4 (589), 39.2-34.0 (650). Anisotropy is moderate to strong both in air and in oil, with blue grey to brown grey polarization colours. Internal reflections and twinning are absent. The optical properties are very similar to boulangerite. Micro-indentation hardness is 222.5 with a range 213-238. Derived Mohs hardness is 3. Cleavage is good, parallel to the c axis. Simplified chemical formula based on electron-microprobe analyses is Pb14.42(35)Sb14.33(11)S36.04(23), Z ¼ 4, which corresponds to Pb 50.74, Sb 29.63, S 19.62, total 100.00 wt%. No other elements exceed detection limits; chlorine is absent and oxygen was not measured. Structural formula is Pb15-2xSb14þ2xS36Ox (Z ¼ 4) for which the above mean of microprobe measurement data and the structure refinement give the value of x equal to � 0.2. Density (calc.) is 7.14 g/cm 3 . Crystal system is monoclinic, space group C2/m, lattice parameters a ¼ 48.189(48) A ˚ , b ¼ 4.1104(40) A ˚ , c ¼ 34.235(35) A ˚ , b ¼ 106.059(15) � , V ¼ 6517(11) A ˚ 3 , Z ¼ 4. Chovanite belongs to a sulphosalt family of boxwork structures, together with pellouxite, scainiite, pillaite, marruccite, vurroite, neyite, and several synthetic sulphosalts. Its crystal structure contains 11 independent lead sites, 13 coordination polyhedra of antimony, some of them with Sb sites split into two partially occupied non-overlapping positions, and five mixed Pb, Sb sites. The boxwork structure of chovanite is formed by a combination of three types of structural modules: (a) continuous walls with a complex structure of rod-layer type; these walls are interconnected by (b) rod-like partitions, and the resulting box-like channels (c) are filled by still another type of structure rods. Chovanite has the largest box-like channel system and infill elements known at present. In spite of differences in chemical composition, chovanite is structurally closest to pellouxite (Cu,Ag)2Pb21Sb23S55ClO which has a moderately large boxwork channel system.

An interesting association of the Bi sulfosalts was identified in the Rozalia mine, Hodrusa–Hamre, Slovakia. Sulfosalts of the cuprobismutite series are the most common, and occur in paragenesis with other Bi sulfosalts, chalcopyrite and hematite. Members of the pavonite homologous series are associated with bismuthinite derivatives and quartz of the amethyst variety. Three members of the cuprobismutite homologous series and four members of the pavonite homologous series have been found in a hydrothermal base-metal mineralization in the Rozalia mine. Kupcikite has the structural formula (Cu 6.73 Fe 1.10 ) ∑7.83 (Bi 9.49 As 0.36 Ag 0.24 ) ∑10.09 (S 18.89 Se 0.13 ) ∑19.02 ; that of hodrusite is (Cu 7.69 Fe 0.38 ) ∑8.07 (Bi 11.22 As 0.34 Ag 0.53 ) ∑12.09 (S 21.99 Se 0.17 ) ∑22.16 , and that of cuprobismutite is (Cu 7.47 Fe 0.14 ) ∑7.61 (Bi 12.81 As 0.69 Ag 1.38 ) ∑14.88 (S 23.85 Se 0.22 ) ∑24.07 . Makovickyite has the structural formula Cu 1.14 Ag 0,99 Pb 0.13 Bi 5.07 S 8.94 Se 0.06 ; that of pavonite is Cu 0.43 Ag 0.82 Fe 0.03 Pb 0.19 Bi 2.84 S 4.96 Se 0.04 , that of dantopaite is Cu 2.29 Ag 3.68 Fe 0.12 Pb 1.32 Bi 12.02 S 21.85 Se 0.15 , that of benjaminite is Cu 1.13 Ag 2.26 Fe 0.16 Pb 0.76 Bi 6.51 S 11.91 Se 0.09, and that of mummeite is Cu 1.44 Ag 2.61 Fe 0.41 Pb 0.95 Bi 6.70 S 12.93 Se 0.07 . The associated sulfosalts are paděraite, berryite and members of the bismuthinite–aikinite series (bismuthinite, gladite, krupkaite, lindstromite, friedrichite and aikinite).

Neoproterozoic pegmatite from Skoddefjellet, Wedel Jarlsberg Land, Spitsbergen: Additional evidence forc. 640 Ma tectonothermal event in the Caledonides of SvalbardNeoproterozoic (c. 640 Ma) amphibolite facies metamorphism and deformation have been shown recently to have affected the Isbjørnhamna and Eimfjellet Complex of Wedel Jarlsberg Land in southwestern Spitsbergen. New SHRIMP zircon U-Pb andin situelectron microprobe monazite and uraninite U-Th-total Pb ages are presented here on a pegmatite occurring within the Isbjørnhamna metasedimentary rocks. Although the dated zircons are full of inclusions, have high-U contents and are metamict and hence have experienced notable Pb-loss, the new Cryogenian ages are consistent with the age of regional metamorphism of the host metasediments, providing additional evidence for a clear distinction of the Southwestern Province from the other parts of the Svalbard Caledonides.

A complex assemblage of Nb-Ta-(Sn) oxide minerals occur in a relatively narrow (~1−2 m thick) extensively albitized, Hercynian granitic pegmatite dike intruding biotite granodiorites near Bratislava, SW Slovakia. The dike shows enrichment in beryl (locally Cs-rich) but absence of Li- and B-rich phases. Compositions and textural relationships indicate complex evolutions of Nb-Ta oxide phases with several generations presenting distinct textural and compositional features. The first generation of the Nb-Ta minerals from the quartz-microcline-muscovite zone show Ta,Fe-rich compositions with Ta# [Ta/(Ta + Nb)] = 0.52−0.70 (Ct I columbite-tantalite), 0.88−0.90 (Tap I ferrotapiolite) and 0.73−0.86 (Fw I ferrowodginite); Mn# [Mn/(Mn + Fe)] = 0.32−0.49 (Ct I), 0.06−0.10 (Tap I) and 0.33−0.41 (Fw I). The 2nd generation is represented by ferrocolumbite to ferrotantalite (Ct II) in saccharoidal albite zone, replacement zones of Ct II in Ct I, and irregular overgrowths of ferrotapiolite (Tap II) and ferrowodginite (Fw II) on Tap I grains. The minerals of the 2nd generation show decreasing of Ta# in comparison to the 1st group: 0.10−0.60 (Ct II), 0.85−0.87 (Tap II) and 0.73−0.77 (Fw II); Mn# attains 0.30−0.45 (Ct II), 0.06−0.09 (Tap II) and 0.26−0.37 (Fw II). The 3rd generation includes fissure fillings, overgrowths and replacement zones of manganocolumbite and manganotantalite (Ct III), ferrotapiolite (Tap III) and ferrowodginite (Fw III) on the older Nb-Ta phases (Ct I, Tap I, Fw I, Fw II), in the coarse-grained unit. The 3rd population displays distinct Mn# increasing (Ct III: 0.51−0.69, Tap III: 0.11−0.24, Fw III: 0.40−0.41), Ta# values reach 0.16−0.79 (Ct III), 0.88−0.92 (Tap III) and 0.80−0.81 (Fw III). The latest, 4th generation of the Nb-Ta phases represents irregular veinlets and patches of fluorcalciomicrolite, replacing Ct I, Tap I, Fw I, Ct II and Tap III. Decrease of Ta/(Ta + Nb) values in Ct II from the saccharoidal albite unit can be explained by crystallization from the albite-rich melt, which was significantly impoverished in Ta with respect to Nb, after crystallization of Ta-rich phases from the 1st generation (ferrotapiolite I, ferrowodginite I).

The pre-Caledonian NYF Skoddefjellet pegmatite in Wedel Jarlsberg Land, Svalbard, contains xenotime-(Y) that is partly replaced by fluorapatite-hingganite-(Y) reaction coronas. Hingganite-(Y) contains up to 2.0 wt.% of Gd2O3, 4.7 wt.% of Dy2O3, 3.3 wt.% of Er2O3 and 5.5 wt.% of Yb2O3. Such unusual, previously undescribed, xenotime-(Y) breakdown was caused by Ca- and F-bearing fluids interacting with the pegmatite. The occurrence of hinnganite-(Y) as a breakdown product of xenotime-(Y) implies that a Be-bearing phase (beryl in this case) was also involved in the reaction. There are few Ca-bearing primary phases in the pegmatite, indicating that the source of fluid was probably located in the generally Ca-richer host rocks (metasediments), though the fluid composition was modified during metasomatism of the pegmatite (i.e. beryl dissolution).

The first documented occurrence of Nb-Ta mineralization in a granitic pegmatite from the Svalbard Archipelago, Arctic Caledonides and the relationships between primary and secondary Nb,Ta-bearing phases are discussed. The Skoddefjellet NYF pegmatite located in southwest Spitsbergen (Wedel Jarlsberg Land) is characterized by enrichment in Nb, U, Zr, Y, REE and Pb, low Zr/Hf (∼8-10), and (∼8-12) Nb/Ta ratios. Columbite-(Fe) and columbite-(Mn) (locally enriched in Ti, Y, Sc and Ca) and Nb,Ta, Y-bearing titanite (≤3.8 wt. % Nb2O5, ≤1.9 wt. % Ta2O5, ≤2.9 wt. % Y2O3) represent the primary magmatic Nb-Ta minerals. The secondary assemblage comprises Nb,Ta-bearing rutile (≤23 wt. % Nb2O5, ≤1.7 wt. % Ta2O5), ilmenite, fersmite and pyrochlore group minerals: including yttropyrochlore-(Y), plumbopyrochlore, yttrobetafite-(Y) and plumbobetafite. Internal zoning of columbite group minerals is expressed by distinct rimward increase of the Mn/(Mn+Fe) ratio (0.07 to 0.83) and low Ta/(Ta+Nb) ratio (0.03 to 0.10), suggesting alkaline environment and increasing fluorine activity during the pegmatite evolution. The formation of secondary phases is related to the hydrothermal stage of the pegmatite. Notably, the formation of Nb,Ta-bearing rutile and ilmenite seems to be a product of Nb,Ta-bearing titanite alteration.

Accessory REE minerals occur in a small metamorphic magnetite ore deposit at Bacuch, Veporic Superunit, central Slovakia. We distinguish two populations of monazite. Monazite I forms subhedral to euhedral crystals associated with magnetite. It contains ≤12 wt.% ThO2, ≤2.7% UO2, ≤0.85% SO3, with low Ca and Sr contents. Compared to the common monazite-(Ce) I, monazite-(Nd) I (≤26.1% Nd2O3) occasionally occurs with an atomic ratio Nd:Ce up to 1.17. Monazite II is present as irregular aggregates with hingganite in younger hydrothermal quartz – albite – chlorite veinlets, or as rim zones on monazite I. Monazite II is depleted in Th and U and has an unusually high content of S (≤11.3% SO3, 0.31 apfu S) and Sr (≤8.7% SrO, 0.18 apfu Sr). This composition indicates a (Ca,Sr)S(REE,Y)−1P−1 substitution as a dominant mechanism of Sr and S entry into the monazite structure. Some monazite II crystals display an elevated Eu content (≤1.2% Eu2O3). Xenotime-(Y) forms subhedral crystals, in association with monazite-(Ce) I, magnetite, pyrite transformed to goethite (?) and quartz. Gadolinite-group minerals at Bacuch are represented by hingganite with an atomic value of X □/ X (□ + Fe) in the range 0.51–0.72. Neodymium is locally the most abundant REE (17.8–18.7% Nd, ~0.56 apfu ), and an Nd-dominant member of the gadolinite group was identified. The composition of hingganite-(Y) was also determined. The principal mechanism of substitution in hingganite is Fe2+O2□−1(OH)−2. Primary monazite I and xenotime are most likely products of regional metamorphism, together with magnetite mineralization. On the contrary, Sr- and S-rich monazite II and hingganite originated during a younger (Alpine) metamorphic-hydrothermal overprint in a fluid-rich regime.

Bi-Se-Te mineralization from Úhorná (Spišsko Gemerské Rudohorie Mts., Słovakia): A preliminary reportAn unusual association of Se minerals was studied. Se enters into the structures of sulphosalts - into bournonite, jamesonite and tintinaite at concentrations up to 0.10, 0.38 and 1.11 apfu, respectively. However, Se and Te, together with Bi, also form discrete minerals such as tetradymite, laitakarite, ikunolite and hedleyite. Members of the laitakarite-ikunolite solid solution display a wide range of anion substitution from the nearly Se-free (0.10 apfu) end member to the S-poor (0.42 apfu) end member. Their contents of Te are low. Accompanying tetrahedrite does not contain Se or Te.

A unique REE–Y–(Th)–P–As–(Si)–(Nb)–(S) accessory assemblage was identified in a small body of Lower Triassic A-type rhyolite of the Silicic Superunit near Tisovec-Rejkovo, Central Slovakia. Arsenian monazite-(Ce)–phosphatian gasparite-(Ce) and arsenian xenotime-(Y)–phosphatian chernovite-(Y) solid solutions in association with REE carbonates (bastnasite, parisite, rontgenite?, synchysite) and rare cerianite-(Ce) form anhedral to subhedral grains and aggregates (≤ 0.3 mm), scattered in the groundass or as intergrowths with zircon and Fe–Ti oxides. Compositions show a wide AsP− 1 substitution in monazite–gasparite and xenotime–chernovite solid solutions; atom. % As/(As+P) = 0.00 to 0.73 and 0.10 to 0.94, respectively. The presence of S in monazite–gasparite s.s. (≤ 0.14 apfu), together with Ca enrichment indicates “clinoanhydrite“ substitution, CaS(REE,Y)− 1 (P,As)− 1, rather than the incorporation of brabantite, along the CaTh(REE,Y)− 2 exchange vector. Moreover, the Th- and Nb-rich members reveal thorite and fergusonite substitutions, ThSi(Y,REE)− 1 (P,As)− 1 and Nb(P,As)− 1, respectively. The As-rich REE phases originated probably during the post-magmatic alteration of primary monazite-(Ce) and xenotime-(Y) by As-rich, high fO2 fluids, whereas cerianite-(Ce) and the REE carbonates are products of a later hydrothermal overprint of the rhyolite by CO2-rich solutions.

Mineralogy and Geochemistry of the Nižná Boca Sb-Au Hydrothermal Ore Deposit (Western Carpathians, Slovakia)Samples from hydrothermal Sb-Au mineralization in the area SE of Nižná Boca village in the N&iAzke Tatry Mountains were investigated using a variety of geochemical and mineralogical methods. Ore minerals typically occur in N-S striking quartz-carbonate veins hosted by an I-type biotite granodiorite to tonalite of Variscan Age (the Ďumbier Type). Paragenetic associations in the deposit are comparable to other mineralizations of the same type in the Ďumbierske Nízke Tatry Mountains. A quartz-arsenopyrite, pyrite stage of mineralization is the oldest with a calculated temperature of formation of about 445°C. It is followed by a quartz-carbonate-stibnite, zinkenite stage and, in turn, a quartz-carbonate-sphalerite-galena, boulangerite-gold stage. The gold typically contains between 9-18 wt.% Ag regardless of mineral association. No evidence for further generations of gold was found although it is possible that some gold was remobilized from the structure of the auriferous arsenopyrite. The Au and Ag content of the bulk ore ranges from 0.53 g.t-1to 20.2 g.t-1and from 0.9 g.t-1to 31.2 g.t-1, respectively. A tetrahedrite-chalcopyrite stage is followed by a barite-hematite stage - the youngest assemblage in the deposit. Fluid inclusions from the first mineralization stage are usually less than 3 μm in size and contain less than 3.6 wt.% CO2; salinity, density and homogenization temperature range from 2.7-16.3 wt.% NaCl(eq), 0.85-1.03 g.cm-1and 128-280°C, respectively.

A Note on the Chemical Composition of Nuffieldite Solid-Solution From Sulphide Mineralizations in the Western Carpathians, SlovakiaThe chemistry of the rare sulphosalt nuffieldite from three localities in Slovakia is examined. Nuffieldite is a part of a complex association of Bi sulphosalts accompanying tetrahedrite mineralization in some sulphide deposits in the Western Carpathians. Cu + Pb = (Bi, Sb) + vac. substitution in nuffieldite and the general formula Cu1+xPb2Bi2(PbxSbyBi1-x-y)S7where 0 < x < 0.34; and 0.32 < y < 0.45 are confirmed. Decreasing Sb content with increasing copper content indicates a predominant substitution of Bi by Sb in nuffieldite.

Three sulphosalts from the cuprobismutite homologous series have been found in a hydrothermal Ni-Bi-As mineralization at Cierna Lehota (Slovakia). Kupcikite (second world occurrence) has a significant content of Pb (2.73 wt.%) and Fe (0.85 wt.%), with the structural formula (Cu 3.92 Fe 0.24 ) Σ4.16 (Bi 4.60 Pb 0.19 Ag 0.04 Sb 0.01 ) Σ4.84 S 9.58 . Hodrushite has a higher content of Ag (mean 1.27 wt.%), but less Fe (0.59 wt.%) and Pb (0.23 wt.%), with structural formula (Cu 7.79 Fe 0.38 ) Σ8.17 (Bi 11.34 Ag 0.43 Pb 0.04 Sb 0.02 ) Σ11.83 S 22.13 . Two varieties of cuprobismutite have the highest Ag content (3.8 and 2.3 wt.%), with Fe 0.6 and 0.2 wt.%, and Pb 0.1 and 6.7 wt.%, giving two formulas (Cu 7.42 Fe 0.47 ) Σ7.87 (Bi 12.56 Ag 1.55 Pb 0.02 ) Σ14.13 S 24.68 and (Cu 7.67 Fe 0.14 ) Σ7.81 (Bi 11.95 Pb 1.37 Ag 0.85 Sb 0.02 ) Σ14.19 S 24.13 . Chemical variations between these sulphosalts are compared with published data, that emphasizes the role of minor cations. Associated sulphosalts are described: aikinite, and Bi-rich tennantite (Bi up to 9.7 wt.%).

Crystal structure of robinsonite from the locality Male Zelezne, Nizke Tatry Mountains, Slovakia, has been refined using single-crystal data (MoKa X-ray diffraction, CCD area detector) to the conventional R-factor: R 1 = 0.045. Robinsonite crystallizes in the space group 12/m, with a = 23.642(4), b = 3.9761(6), c = 24.420(4) A, β = 93.808(3)° and Z = 4. X-ray diffraction and chemical analysis resulted in comparable formulae, Pb 4 . 0 3 Sb 5 . 9 7 S 1 3 and Pb 3 . 9 3 Sb 5 . 7 7 S 1 3 , respectively, which are close to the ideal formula Pb 4 Sb 6 S 1 3 . Robinsonite is a member of a large family of rod-based sulphosalts, composed of rods of SnS (or TII) archetype. In robinsonite, two types of rods, respectively 2 and 3 Sb coordination pyramids broad, combine. Their arrangement results in two types of rod-layers, denoted according to their inter-rod connections as Type 1 and Type 4, respectively. In the former case, a tightly bonded double-layer continues from one rod into the other. In the latter, the rods are interconnected by the smallest possible fragment of SnS-like configuration that is rotated 90° in respect to the SnS-like (TIl-like) arrangement in the rod interiors. The mixed cation sites are the main characteristic of the robinsonite structure. The present study is the second one performed on natural robinsonite and the first in which all mixed positions are successfully refined. The mixed sites are concentrated in slabs parallel to [010]. The composition of these slabs can be explained by the necessity to match dimensions of the structure motifs across a noncommensurate interspace. Comparison with monoclinic boulangerite shows many similarities in distribution of mixed cation sites.

This study reports silver mineral association found recently in the Stan Terg lead and zinc mine, located in the Vardar Zone (in the northern Kosovo). The described mineralization comprises pyrargyrite, freieslebenite, high-Ag bearing tetrahedrite, freibergite and native compounds (electrum, native silver, native antimony). Ag-minerals occur in vuggs and cracks in massive galena ore, and have signs of the latest precipitated minerals in the deposit. The chemical composition of those minerals was confirmed by the electron microprobe. Freibergite from the Stan Terg deposit reveals zonality and contains between 13.91-20.28 at. % of Ag. High Ag solutions are indicated also by relatively high silver content in electrum, which is between 47.02 and 73.19 at. % of Ag. The Ag association is supposed to be an epithermal equivalent of precious metal mineralization which could be located in the external part of the Stan Terg hydrothermal system. This association occurs in low temperatures, below 200˚C. The Ag-minerals can be part of epithermal veins from the external part of the Stan Terg hydrothermal system. Similarly to the other know Pb-Zn-Ag hydrothermal system, silver association is related to formation of the rhodochrosite banded ore and Ag-Au-Sb±Hg dominated mineralization.

Kosovo lead and zinc ore deposits are located in the Trepca Belt which extends for over 80 km. Several ore deposits occur in that belt, with the most important - Stan Terg (Trepca). Stan Terg deposit originating at the contact between volcanic breccias and carbonate rocks. Two different types of mineralization can be distinguished. The older one has origin related to pneumatolitic processes, when skarns were formed. The more recent one was formed by hydrothermal processes and has the largest economic importance. Over 70 minerals have been recognized in the Trepca deposit. Further mineralogical investigations will allow for the identification of other rare minerals.