Horní Počernice, Czech Republic
Horní Počernice, Czech Republic

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Paulis P.,Smiskova 564 | Venclik V.,Na drazce 1501 | Malikova R.,Mineralogicko petrologicke oddeleni | Pour O.,Ceska geologicka sluzba | Jiri Sejkora A.,Mineralogicko petrologicke oddeleni
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2015

Phosphosiderite was found at mine dumps material of the abandoned Fe-Mn occurrence Zdechovice (19 km E from Kolín, Czech Republic). It forms there whitish, greyish white and mauve coatings and crusts with area more than 10 cm2 on weathered slate rocks. Phosphosiderite is monoclinic, space group P21/n, the unit-cell parameters refined from X-ray powder diffraction data are: a 5.330(3), b 9.807(7), c 8.706(4) Å, β 90.60(5)o and V 455.1(5) Å3; its chemical composition is close to ideal formula Fe3+PO4∙2H2O. White crystals and aggregates of gypsum, yelow-brown nodules of destinezite (triclinic, space group P-1, unit-cell parameters: a 9.562(8), b 9.715(6), c 7.319(5) Å, α 98.75(5), β 107.91(5), γ 63.87(5)o and V 580.8(8) Å3) and white to greyish white aggregates od fluorapatite (hexagonal, space group P 63/m, unit-cell parameters: a 9.417(7), c 6.8761(3) Å and V 528.1(4) Å3) were observed in association. Similar occurrence of phosphosiderite (monoclinic, space group P21/n, the unit-cell parameters: a 5.334(4), b 9.817(6), c 8.700(4) Å, β 90.60(3)o and V 455.7(5) Å3) was confirmed at historical sample from nearby Chvaletice deposit near Přelouč. © 2015, National Museum Prague. All rights reserved.


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.


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).


Cerny P.,Gorkeho 257 | Cerny P.,R.Ø.S.A. | Vrtiska L.,Mineralogicko petrologicke oddeleni | Malikova R.,Mineralogicko petrologicke oddeleni | Exnar P.,Technical University of Liberec
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2015

A new occurrence of jarosite in ordovician sediments of the Barrandian area was found in the abandoned quarry Milina near Hořovice, Czech Republic. Jarosite forms there yellow, amber yellow, yellow-brown to brown tabular, rhombohedral or pseudo-octahedral crystals up to 1.5 mm in size. Jarosite is trigonal, space group R-3m, with a 7.286(3), c 17.2189(1) Å, V 791.7(3) Å3 and its average composition Na2O 0.20, Al2O3 1.40, Fe2O3 44.52, K2O 8.33, SO3 30.62, P2O5 0.76, MoO3 0.71, H2Ocalc. 10.28, total 96.81 wt. % corresponding to the formula (K0.89Na0.03)Σ0.92(Fe2.80Al0.14)Σ2.94 [(SO4)1.92 (PO4)0.05(MoO4)0.03]Σ2.00 (OH)5.73 on the basis of P+S+Mo = 2 apfu. © 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.


Pazout R.,Vysoka skola chemicko technologicka Prague | Jiri Sejkora A.,Mineralogicko petrologicke oddeleni
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2015

A rare oxychloride of lead and antimony, the mineral nadorite, was found in an ore sample from the Kutná Hora ore district, Central Bohemia. It is the first occurrence of this mineral in Czech Republic. The mineral was identified in a polished section as a dark elongated grain approximately 30 μm accros, enclosed in boulangerite in association with galena. The chemical composition of nadorite is close to the ideal formula of this mineral with only minor contents of As (0.02 - 0.04 apfu) which probably substituted Sb. The average chemical composition (mean of 3 point analyses) of nadorite: Pb 51.88, Sb 31.45, As 0.61, Ocalc. 8.31, Cl 9.25, total 101.51 wt. %, corresponds to the empirical formula Pb0.97(Sb1.00As0.03)Σ1.03O2.00Cl1.01 on the basis of Pb+Sb+As+Cl = 3 apfu. © 2015, National Museum Prague. All rights reserved.


Sejkora J.,Mineralogicko petrologicke oddeleni | Malikova R.,Mineralogicko petrologicke oddeleni | Novak M.,Ustav chemicke Technology restaurovani pamatek
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2015

Three types of samples-large crystals of pyrite from Navajún (Spain), crystals of pyrite from San Jose de Huanzala (Peru) and crystals of marcasite from Bílina (Czech Republic) were altered in controlled conditions with RH in the range 30-97%. Eight mineral phases-coquimbite, copiapite, ferricopiapite, kornelite, paracoquimbite, rhomboclase, rozenite and szomolnokite were identified by PXRD as alteration products. The descriptions and refined unit-cell parameters are given for all determined mineral phase. The differences between studied mineral association and mineral phases formed by alteration of Fe-sulphides in the museum collection are discussed in the paper. © 2015, National Museum Prague. All rights reserved.


Sejkora J.,Mineralogicko petrologicke oddeleni | Skacha P.,Mineralogicko petrologicke oddeleni
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2015

Mineral phases of clausthalite - galena solid solution were found at samples of siderite - fluorite - quartz gangue from the abandoned fluorite - baryte mine Běstvina, Železné hory Mountains (eastern Bohemia, Czech Republic). They occur as irregular grains up to 0.5 mm in size and tiny veins in coffinite and rarely uraninite. The solid solution series covers the range PbSe1.00to Pb(S0.58Se0.42) virtually free of gaps and two groups of Se-containing galena with 0.10 - 0.13 and 0.26 - 0.27 apfu Se, respectively. Younger sulphides (pyrite, sphalerite, chalcopyrite) were found in the association. Pyrite is As-rich with empirical formula Fe1.00(S1.98As0.02)Σ2.00. Sphalerite with minor contents Fe, Cd and Cu has empirical formula (Zn0.98Fe0.01Cd0.01)Σ1.00S1.00. Chemical composition of chalcopyrite is possible to express as Cu0.98(Fe0.98Zn0.02)Σ1.00S2.02. © 2015, National Museum Prague. All rights reserved.


In this research 18 samples of tetrahedrite containing mercury were collected from six localities in the Czech Republic, Slovakia and Bosnia. The samples were subjected to detail microprobe and x-ray diffraction analyses and subsequent refinement of unit-cell parameters. Tetrahedrites from the Jedová Hora locality (Czech Republic) are rich in mercury (1.46-1.73 apfu); tetrahedrites from the Rudňany deposit (Slovakia) have a variable content of Hg, Fe and Zn (Hg rich samples with 1.47-1.79 apfu of Hg; Fe rich sample with 1.06 apfu of Fe and Zn rich sample with 1.79 apfu of Zn); tetrahedrites for the Rožňava deposit (Slovakia) are mostly Fe rich (1.53 - 1.75 apfu); Hg rich sample from Rožňava contains 1.65 apfu of Hg. Two samples of tetrahedrites from the Nižná Slaná deposit (Slovakia) are rich in Hg (1.07 and 1.39 apfu); analyzed sample from the Slovinky deposit (Slovakia) is rich in Zn (1.13 apfu). Samples from the Maškara deposit (Bosnia) contain more Fe than Hg (Fe: 0.93 - 1.33 apfu; Hg: 0.19-0.76 apfu). The mercury content in the samples showed a positive linear correlation to the unit cell parameters (0.19 apfu ~ 10.32 Å to 1.79 apfu ~ 10.46 Å). © 2014, Bull. mineral.-petrolog. Odd. Nár. Muz. (Praha). All rights reserved.


Sejkora J.,Mineralogicko petrologicke oddeleni | Skacha P.,Mineralogicko petrologicke oddeleni
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2015

A mineral association of Pb, Ag and Bi selenides in carbonate - fluorite - quartz gangue was found at samples from the abandoned fluorite mine Moldava in the Krušné hory Mts. (northern Bohemia, Czech Republic). The minerals from the clausthalite - galena solid solution are the most abundant; four their types were determined on the base of chemical composition and associations. The first occurs as fine-grained aggregates up to 2 mm in size and impregnations for¬med by irregular grains up to 100 μm across (some with naumannite) and rarely also idiomorphic crystals up to 5 μm in coffinite. It is clausthalite with S contents up to 0.14 apfu. The second type forms grains up to 20 μm in association with native Ag, naumannite and Se-rich acanthite, it is clausthalite with S contents in the range 0.24 - 0.32 apfu. The third type is represented by aggregates up to 200 μm of Se-rich galena (to clausthalite) in association with bohdanowiczite and Ag-Pb-Cu-Bi-(Se,S) phase with Se contens in the range 0.38 - 0.48 apfu. The fourth type forms aggregates up to 100 μm across in association with aikinite and it is galena with Se contents in the range 0.17 - 0.45 apfu. Naumannite was found as aggregates up to 100 μm in size, its empirical formula can be expressed as Ag1.00(Se0.97S0.02)Σ0.99. Se-rich acanthite (0.11 - 0.49 apfu Se) occurs as grains up to 90 μm across in association with native Ag, naumannite and coffinite. S-rich bohdanowiczite forms aggregates up to 80 μm in size in association with Se-rich galena and Ag-Pb- Cu-Bi-(Se,S) phase; its chemical composition corresponds to the empirical formula (Ag1.05Pb0.01)Σ1.06Bi1.01(Se1.30S0.63)Σ1.93. Aikinite was found only rarely as grains up to 20 μm in association with Se-rich galena, its empirical formula is (Cu3.85Fe0.20)Σ4.05Pb4.04Bi3.95(S12.19Se0.45)Σ12.64. The aggregates of Ag-Pb-Cu-Bi-(Se,S) phase occurs in association with Se-rich galena and bohdanowiczite; its chemical composition is very variable; this phase is interpreted as submicroscopic (< 1 μm) intergrowths of aikinite and bohdanowiczite. The native silver forms grains up to 100 μm in association with naumannite, Se-rich acanthite and coffinite. The described mineral association was probably formed from two or more fluids exhibiting different fSe2/fS2ratios and disequilibrium of system. © 2015, National Museum Prague. All rights reserved.

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