Katedra mineralogie a petrologie

Bratislava, Slovakia

Katedra mineralogie a petrologie

Bratislava, Slovakia
SEARCH FILTERS
Time filter
Source Type

Bonova K.,Ustav geografie | Bacik P.,Katedra mineralogie a petrologie | Bona J.,kpt. Jarosa 780 13
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2012

The hexahydrite and ranciéite have been found in travertine or calcareous tufa, respectively in the Vyšné Ružbachy locality. They were identified by the X-ray diffraction methods. Hexahydrite occurs in the thin layers of white colour covering the weathering rocks. Chemical weathering of carbonate rocks is considered to be source of magnesium ions and sulphate can be of Triassic origin. Intergranular sources of carbonates for the soluble magnesium salts are alternatively assumed. Ranciéite forms the iron grey to black substances in the cavern of calc-tufa. Its occurrence is probably linked with precipitation from the thermal waters together with bacterial participation.


Uher P.,Katedra mineralogie a petrologie | Kodera P.,Katedra loziskovej geologie | Ozdin D.,Katedra mineralogie a petrologie
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2012

Kerimasite Ca 3Zr 2(Fe 3+ 2Si)O 12, a rare member of garnet supergroup, was identified by EMPA in Ca-Mg skarn on the contact between Miocene granodiorite porphyry intrusion and Middle Triassic dolomites in a borehole from the Cu-Au skarn-porphyry deposit Vysoká-Zlatno near Banská Štiavnica (Štiavnické Vrchy Mts., Central Slovakia). Kerimasite forms isolated irregularly shaped grains (60 - 100 μm across) in association with andradite, monticellite, clintonite, magnetite, perovskite and brucite. Kerimasite originated during prograde metamorphic conditions of high-temperature contact thermal metamorphism related to emplacement of the granodiorite porphyry into dolomites.


Stevko M.,Katedra mineralogie a petrologie | Malikova R.,Mineralogicko petrologicke oddeleni
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2014

An interesting supergene mineral association was identified at the abandoned Juraj adit near Hodruša-Hámre village, Štiavnické vrchy Mts., Slovak Republic. It is represented by allophane, anglesite, brochantite, calcite, cerussite, dundasite, gypsum, hydrozincite, linarite, malachite, posnjakite and zincowoodwardite. Anglesite occurs as well developed, colourless, tabular to prismatic crystals up to 3 mm in vugs of weathered galena-rich gangue. It is orthorhombic, space group Pnma, the unit-cell parameters refined from X-ray powder diffraction data are: a = 8.447(1), b = 5.3863(10), c = 6.9563(9) Å and V = 317.63(9) Å3. Cerussite is the most common supergene mineral and it forms colourless to white tabular, prismatic or acicular crystals up to 9 mm in size, which are often twinned and are associated together with dundasite, malachite and linarite in the cavities of gangue or mineralized rocks. The refined unit-cell parameters of cerussite from the powder X-ray diffraction data (for the orthorhombic space group Pmcn) are a = 5.174(1), b = 8.478(2), c = 6.135(1) Å with V = 269.1(1) Å3. Dundasite forms white or pale-blue, radial to spherical aggregates up to 1 mm, which are composed of well formed acicular crystals and cover areas up to 4 × 1.5 cm in cavities of ore gangue. Its refined unit-cell parameters from the powder X-ray diffraction data (for the orthorhombic space group Pbnm) are a = 9.071(2), b = 16.394(5), c = 5.618(2) Å and V = 835.4(5) Å3. Hydrozincite occurs as compact, white, up to 1 cm thick crusts or botryoidal aggregates on the adit walls together with calcite and zincowoodwardite. It is monoclinic, space group C2/m, the unit-cell parameters refined from X-ray powder diffraction data are: a = 13.63(2), b = 6.319(8), c = 5.397(9) Å, β = 95.9(3)° and V = 462(1) Å3. Linarite often forms well developed, bright blue, tabular to prismatic crystals up to 4 mm in size, which are often grouped to the radial aggregates and crystalline crusts in cavities and fractures of ore gangue (together with cerussite, dundasite and malachite) or on the walls of adit (associated with brochantite, gypsum, posnjakite and zincowoodwardite). Its refined unit-cell parameters from the powder X-ray diffraction data (for the monoclinic space group P21/m) are a = 9.691(3), b = 5.650(2), c = 4.686(2) Å, β = 102.68(2)° and V = 250.3(1) Å3. Rare posnjakite occurs as pale blue, acicular crystals up to 1 mm, which were observed on the adit walls associated together with brochantite, linarite and zincowoodwardite. The refined unit-cell parameters of posnjakite from the powder X-ray diffraction data (for the monoclinic space group Pm) are a = 10.569(14), b = 6.349(4), c = 7.857(9) Å, β = 117.94(7)° and V = 465.7(9) Å3. Zincowoodwardite was observed exclusively on the walls of adit as an white-blue to pale-blue crusts with botryoidal surface, which covers areas up to 5 × 4 cm. Associated minerals include brochantite, calcite, gypsum, hydrozincite, linarite and posnjakite. It is trigonal, space group P-3, the unit-cell parameters refined from X-ray powder diffraction data are: a = 3.057(9), c = 8.865(8) Å with V = 71.8(2) Å3. A newly described association of supergene minerals from the Juraj adit was formed as a sub-recent product of decomposition of primary sulfidic mineralization (mostly galena, sphalerite, chalcopyrite and pyrite) in the conditions of abandoned mine. © 2016, National Museum Prague. All rights reserved.


Balintova-Stevkova T.,Agentura na podporu vyskumu a vyvoja | Stevko M.,Katedra mineralogie a petrologie | Ozdin D.,Katedra mineralogie a petrologie | Bakos F.,Konopiska 43
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2014

Pilsenite, ideally Bi4Te3 was found in the body of hydrothermal metasomatites, which is located near Poruba pod Vihoraltom, Vihoralt Mts., Slovak Republic. It forms lead-grey, subhedral grains up to 7 mm in size with typical perfect cleavage. Pilsenite grains are often grouped into the aggregates and clusters up to 3 × 2 cm, which are embedded in brownish metasomatite. Its refined unit-cell parameters from the powder X-ray diffraction data (for the trigonal space group R-3m) are a = 4.430(4), c = 41.834(3) Å with V = 710.971(1) Å3. The chemical composition of pilsenite is close to the end member and apart from Bi and Te only minor contents of Pb (up to 0.06 apfu), Se (up to 0.03 apfu) and S (up to 0.03 apfu) were detected. Its average empirical formula is (Bi3.95Pb0.05)Σ4.00(Te2.96Se0.02S0.02)Σ3.00 on the basis of 7 apfu. © 2016, National Museum Prague. All rights reserved.


Stevko M.,Katedra mineralogie a petrologie | Sejkora J.,Mineralogicko petrologicke oddeleni | Bacik P.,Katedra mineralogie a petrologie
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2013

Witherite, ideally BaCO3, was identified at the Dúbrava antimony deposit, Nízke Tatry Mts., Slovak Republic. It forms irregular coarse grained white to very pale yellow aggregates up to 2.5 × 1 cm in size with vitreous to greasy lustre, which fills drusy cavities in quartz. It is closely associated together with yellow aggregates and tabular crystals of barite, crystalline Fe-rich dolomite and strontianite. Witherite was also observed as an irregular microscopic inclusions in barite. The refined unit-cell parameters of witherite from Dúbrava antimony deposit are: a = 5.3001(9) Å, b = 8.8751(14) Å, c = 6.4150(10) Å and V = 301.76(8) Å3. Quantitative chemical analyses of witherite correspond to the empirical formula (Ba0.96Sr0.04)Σ1.00CO3. The origin of witherite is hydrothermal; it was formed together with barite and strontianite as an product of late low-thermal fluids. © 2013 National Museum Prague. All rights reserved.


Stevko M.,Katedra mineralogie a petrologie | Sejkora J.,Mineralogicko petrologicke oddeleni | Litochleb J.,Mineralogicko petrologicke oddeleni | Macek I.,Mineralogicko petrologicke oddeleni | Bacik P.,Katedra mineralogie a petrologie
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2013

An interesting hydrothermal ore mineralization with krutovite has been found in the abandoned serpentinite-asbestos quarry near Dobšiná, Slovak Republic. It is represented by a lenticular nearly subhorizontal vein which is up to 15 cm thick and more than 2 m long and was developed on the contact between the serpentinite breccias and limestones. Quartz and calcite are the main gangue minerals. The most abundant ore mineral is nickeline which is associated with krutovite and galena. Primary ore minerals are often replaced by aggregates of bright green supergene Ni-silicates and mimetite. Krutovite forms metallic, greyish-white individual grains and botryoidal aggregates up to 5 mm in quartz-Ni-silicate mass or microscopic zones in aggregates of older nickeline. Its refined unit-cell parameters are: a = 5.8131(8) Å and V = 196.43(9) Å3. The chemical composition of krutovite from Dobšiná is close to the end member formula and only minor amounts of Cu (up to 0.009 apfu), Hg (up to 0.002 apfu), Sb (up to 0.004 apfu), S (up to 0.047 apfu) and Se (up to 0.014 apfu) were detected. Nickeline occurs as metallic, copper-red irregular grains and aggregates up to 2 cm or veinlets up to 8 cm long and 1 cm thick which are embed in quartz-calcite gangue and are often heavily replaced by supergene green Ni-silicates. Its refined unit-cell parameters are: a = 3.6177(2) Å, c = 5.0404(3) Å and V = 57.129(8) Å3 and it shows mostly uniform chemical composition with only low contents of Se (up to 0.005 apfu) and S (up to 0.048 apfu). Rarely also microscopic aggregates of unusual S-rich nickeline (up to 0.217 apfu S) or Ni-deficient disordered nickeline were observed together with krutovite. These phases may represent nickeline with the submicroscopic (under the 0.1 μm) inclusions of krutovite or products of diffusion of krutovite to the older nickeline during the replacement. Galena is common mineral in studied association and it forms irregular aggregates or veinlets up to 1 cm. It is often strongly replaced by mimetite or anglesite so its relationship to the nickeline and krutovite is unclear. The chemical composition of galena from Dobšiná is rather simple and only minor amounts of Sb, As, Bi and Se were detected.


Sejkora J.,Mineralogicko petrologicke oddeleni | Stevko M.,Katedra mineralogie a petrologie | Macek I.,Mineralogicko petrologicke oddeleni
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2013

The minerals of the tetrahedrite isotypic series are the main ore phases at the Piesky deposit and in the past they were the most important source of copper and silver at the whole Špania Dolina ore district (central Slovakia, Slovak Republic). They occur as veinlets, impregnations or massive aggregates up to 10 cm in size, which are associated together with chalcopyrite in quartz-carbonate veins or in mineralized rocks and are often altered to the yellowish-green aggregates of amorphous Cu-Sb-Fe phases or diverse supergene minerals. The chemical composition of minerals of the tetrahedrite isotypic series from the various parts of the Piesky deposit is rather uniform. In the trigonal site Cu is dominant element and only low content of Ag (up to 0.04 apfu) was detected. The overall content of divalent metals like Fe, Zn as well as slight amount of Pb in the tetrahedral site is up to 1.3 - 1.7 apfu, which together with elevated content of Cu (higher than theoretical value of 10 apfu) suggest the presence of at least some Cu2+ in this possition. In the X possition Sb is the prevalent element, so As-rich tetrahedrite is the absolutely dominant species at the Piesky deposit. Only in one case, Sb-rich tennantite as an irregular zones up to 50 μm in size was observed in the As-rich tetrahedrite. Characteristic feature of tetrahedrite-tennantite minerals from the Piesky deposit is regular content of Bi (up to 0.14 apfu).


Majzlan J.,Friedrich - Schiller University of Jena | Stevko M.,Katedra mineralogie a petrologie | Chovan M.,Institute geologickeho inzenyrstvi
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2015

In this contribution, we studied mineralogy of a small, long abandoned ore occurrence near the village of Hiadeľ in the Nízke Tatry Mts. (Slovakia). An earlier mineral association consists of pyrite I, arsenopyrite, rutile, apatite, monazite, and possibly zircon. This association is located in alteration zones with abundant sheet silicates. Carbonates are found in this association but also in the milky quartz that contains no sheet silicates. The composition of the carbonates is variable; they belong to the siderite-magnesite and dolomite-ankerite solid solution, rarely to calcite. Later ore minerals are represented by stibnite, Pb-Sb sulfosalts (zinkenite, jamesonite, or robinsonite), tetrahedrite, chalcostibite, bournonite, and pyrite II. The temporal relationship among these minerals cannot be determined from our samples. Tetrahedrite is Zn-rich and Ag-poor. From a mineralogical point of view, this occurrence does not deviate from other ore deposits and occurrences known in the Tatric part of the Nízke Tatry Mts. © 2015, National Museum Prague. All rights reserved.


Stevko M.,Katedra mineralogie a petrologie | Sejkora J.,Mineralogicko petrologicke oddeleni | Plasil J.,Fyzikalni ustav
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2012

An interesting association of supergene uranium minerals represented by natrozippeite, zinczippeite, andersonite and zellerite was found at the 12th level of Banská Štiavnica base metal deposit. The most abundant supergene phase, natrozippeite forms bright yellow crystalline coatings which consist of tiny tabular crystals up to 5 μm in size on quartzsulfide gangue with disseminated uraninite. It is associated together with zinczippeite, gypsum and melanterite. Its refined unit-cell parameters are: a = 17.664(3) Å, b = 14.650(1) Å, c = 17.711(2) Å, β = 104.45(1)°, V = 4438(1) Å3. Electron microprobe analyses of natrozippeite yielded its average chemical composition Na2O 3.05, K2O 0.25, CaO 0.03, MgO 0.13, PbO 0.31, CuO 0.15, MnO 0.06, ZnO 0.27, Al2O3 0.12, SiO2 0.36, SO3 10.12, UO3 76.90, H2Ocalc. 8.05, total 99.80 wt. % corresponding to the empirical formula (Na2.97K0.16Mg0.10Zn0.10Al0.07Cu0.06Pb0.04Mn0.03Ca0.02)Σ3.54[(UO2)8.12(SO4)3.82(SiO4)0.18O5(OH)3]·12H2O on the basis (S+Si) = 4 apfu. Zinczippeite was found as orange-yellow fine crystalline irregular aggregates formed by tiny and imperfect thin-tabular crystals up to 10 μm in size together with natrozippeite, gypsum and melanterite on quartz-sulfide gangue with disseminated uranium mineralization. The refined unit-cell parameters of zinczippeite are: a = 8.655(4) Å, b = 14.261(4) Å, c = 17.691(8) Å, β = 104.16(4)°, V = 2117(1) Å3 and its average chemical composition is Na2O 0.26, K2O 0.48, CaO 0.23, FeO 1.12, MgO 0.50, PbO 0.60, CuO 0.27, MnO 0.25, ZnO 4.33, Al2O3 0.14, SiO2 0.42, P2O5 0.17, SO3 9.71, UO3 73.83, H2Ocalc. 8.24, total 100.53 wt. % corresponding to the empirical formula (Zn0.41Fe0.12Mg0.09K0.08Na0.06Ca0.03Cu0.03Mn0.03Al0.02Pb0.02)Σ0.89[(UO2)1.97(SO4)0.93(SiO4)0.05(PO4)0.02O2]·3.5H2O on the basis (S+Si+P) = 1 apfu. Andersonite forms rare transparent apple-green irregular crystals up to 1 mm on quartzsulfide gangue with disseminated uraninite and abundant coarse-grained aggregates of carbonate (calcite). Its refined unit-cell parameters are: a = 17.9184(6) Å, b = 23.752(1) Å, V = 6604.4(4) Å3. Qualitative chemical analysis showed only presence of Ca, Na, U, C and O which is consistent with ideal chemical composition of this mineral. Zellerite is the rarest phase in the studied mineral association, it occurs as pale-yellow spherical or reniform aggregates up to 0.2 mm on quartz-sulfide gangue with disseminated uraninite and abundant coarse-grained aggregates of calcite. The refined unit-cell parameters of zellerite are: a = 11.268(9) Å, b = 19.11(1) Å, c = 4.900(3) Å, V = 1055.2(9) Å3 and its qualitative chemical analysis showed presence of Ca, U, C and O which agrees with the ideal chemical composition of this phase. Described association of supergene uranium minerals represents sub-recent alteration products of primary uraninite, coffinite and base metal sulfides in the environment of the abandoned mine adit.


Uher P.,Katedra mineralogie a petrologie | Ferenc S.,Katedra geografie | Spisiak J.,Katedra geografie
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2013

Unique chromian-nickeloan muscovite occurs in magnesite-dolomite-quartz listvenite rock (carbonatized and silicified serpentinite) from Muránska Zdychava near Revúca (Veporic Superunit, Slovenské rudohorie Mts., central Slovakia). Muscovite forms anhedral aggregates and veinlets in quartz and carbonate groundmass, up to 20 μm across. It shows emerald-green colour, electron-microprobe analyses revealed 9.5 to 12 wt. % Cr2O3 (0.52 - 0.67 apfu) and 2.1 to 4.5 wt. % NiO (0.11 - 0.25 apfu). The average crystallochemical formula of the Cr,Ni-rich muscovite is close to K0.65(Al1.13Cr0.59Ni0.19Mg0.16Fe0.05)Σ2.12(Si3.33A l0.67)Σ4.00(OH)1.90F0.10. The Ni contents belong to the highest concentrations of this element ever obtained on a mineral of mica group. The Cr-Ni muscovite is associated with accessory chromite, pyrite, and Ni-sulphide minerals (pentlandite, violarite, ullmannite and millerite). The Cr,Ni-rich muscovite and associated minerals of listvenite originated by hydrothermal-metasomatic overprint on primary, Lower Paleozoic metaultrabasic rocks during Alpine (Cretaceous) orogenesis.

Loading Katedra mineralogie a petrologie collaborators
Loading Katedra mineralogie a petrologie collaborators