Mineralogicko petrologicke oddeleni

Horní Počernice, Czech Republic

Mineralogicko petrologicke oddeleni

Horní Počernice, Czech Republic
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Plasil J.,Fyzikalni ustav AV CR v.v.i. | Cejka J.,Mineralogicko petrologicke oddeleni | Skoda R.,Masaryk University
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2014

A rare supergene Cu-Al sulfate, mineral chalcoalumite, has been found for the first time in the Czech Republic from Jáchymov. This supergene mineral was identified in the material originating from the Červená vein, Rovnost mine (Jáchymov) in an association with other supergene minerals, related by their origin to the acid mine drainage, mostly sulfates of copper and uranium. The chemical composition of the studied chalcoalumite was determined using an electron microprobe. The empirical formula can be expressed as (Cu0.91Fe0.05Ni0.01)Σ0.97Al3.86 [(SO4)0.99(SiO4)0.01]Σ1.00(OH)11.47. 3H2O (mean of 4 spot analyzes; on the basis of S + Si = 1 apfu). The unit-cell parameters of studied chalcoalumite refined from the powder X-ray diffraction data (for the monoclinic space group P21/n) are a = 10.24(1), b = 8.938(8), c = 17.09(2) Å, β = 95.7(2)° and with V = 1557(3) Å3. © 2014, National Museum Prague. All rights reserved.


Sejkora J.,Mineralogicko petrologicke oddeleni | Plasil J.,Fyzikalni ustav | Bures B.,Plevenska 3111
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2013

An unusual association of supergene uranium minerals was found at old abandoned mine working at area of the Jan Evangelista vein, Daniel level of mine Svornost, central part of the Jáchymov ore district, Krušné hory Mountains, Czech Republic. Sklodowskite occurs there as rich whitish yellow fine crystalline agregates at area up to 2 x 3 cm of strongly supergene altered gangue formed by tiny acicular crystals up to 10 μm in length. It is monoclinic, space group C2/m; the unit-cell parameters refined from X-ray powder diffraction data are: a 17.36(1), b 7.054(4), c 6.619(5) Å, β 105.79(7)o and V 780(1) Å3; its chemical analyses correspond to the empirical formula (Mg0.92Fe0.01Ni0.01 Cu0.01Co0.01Ca0.01)Σ0.97(UO2)2 (SiO3OH)2.01(SO4)0.04(PO4)0.02(AsO4)0.01.6H2O on the basis 2 apfu U. Compreignacite forms yellow irregular aggregates up to 3 mm in size at area up to 1 x 1 cm of altered gangue with rare prismatic crystals up to 20 μm. It is orthorhombic, space group Pnnm; the unit-cell parameters refined from X-ray powder diffraction data are: a 14.847(2), b 7.212(1), c 12.151(4) Å, and V 1301.1(3) Å3; its chemical analyses correspond to the empirical formula (K1.07Na0.05Pb0.04Mg0.03Cu=Ni0.02Al0.02)Σ1.25 [(UO2)6O4(SiO4)0.08(OH)5.16].7H2O on the basis 6 apfu U. Two chemically different types of fourmarierite were found. Pb-deficient and K-rich fourmarierite F1 forms dark yellowish orange to orange fine crystalline aggregates up to 2 mm in size with tiny tabular crystals up to 20 μm. It is orthorhombic, space group Bb21m, the unit-cell parameters refined from X-ray powder diffraction data are: a 14.025(2), b 16.469(3), c 14.623(2) Å, and V 3378(2) Å3; its chemical analyses are given in the tables. Fourmarierite F2 is more rare, it occurs as orange red or orange brown aggregates in association with compreignacite. It is orthorhombic, space group Bb21m, the unit-cell parameters refined from X-ray powder diffraction data are: a 13.442(5), b 16.611(6), c 14.447(2) Å, and V 3226(1) Å3; its chemical analyses are given in the tables. Unnamed „Na-metaschoepite“ forms pale yellowish orange powdery or fine crystalline aggregates up to 3 mm in size is association with compreignacite, fourmarierite and gypsum. It is orthorhombic, space group Pbcn, the unit-cell parameters refined from X-ray powder diffraction data are: a 14.025(2), b 16.469(3), c 14.623(2) Å, and V 3378(2) Å3; its chemical analyses correspond to the empirical formula (Na0.30Cu0.13Al0.13 K0.08Pb0.07Ca0.06Mg0.06Mn0.02Zn0.02Fe0.02 Ni0.01Co0.01)Σ0.91[(UO2)4O2(SiO4)0.26(SO4)0.02(OH)4.46].5H2O on the basis of 4 apfu U. The origin of described mineral association is interpreted as product of (sub)recent weathering of primary uraninite in neutral of only weak-acidic conditions. © 2013, National Museum Prague. All rights reserved.


Sejkora J.,Mineralogicko petrologicke oddeleni | Litochleb J.,Mineralogicko petrologicke oddeleni | Cejka J.,Mineralogicko petrologicke oddeleni | Cerny P.,Gorkeho 257
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2013

An interesting uranyl silicate association (kasolite, weeksite) was found at the small uranium ore occurrence Zborovy-Nicov near Plánice (SW Bohemia, Czech Republic). Kasolite forms there abundant powder to massive hemisperical aggregates (pseudomorphoses after uraninite) in a strongly supergene altered gangue and veinlets up to 2 cm; it is yellow with orange or light brown tints. Kasolite is monoclinic, space group P21/c, the unit-cell parameters refined from powder X-ray data are: a 6.716(2), b 6.924(5), c 13.256(6) Å, β 104.17(3)° and V 597.6(5) Å3. Chemical analyses yielded to the empirical formula (Pb0.88K0.05)Σ0.93(UO2)1.02(SiO4)1.00 . H2O. Weeksite was identified only at some samples; it forms light yellow (some with greenish tint) massive aggregates up to 1-3 cm in size, pseudomorphs after hemispherical aggregates of uraninite or irregular aggregates and veinlets in gangue. It is monoclinic, space group C2/m, with the unit-cell parameters: a 14.197(1), b 14.203(1), c 9.631(1) Å, β 111.624(7)o and V 1805.3(4) Å3. Its empirical formula is (K0.57Ba0.33Ca0.13Al0.06Co0.02Pb0.01)Σ1.12(UO2)2.02Si5O13 . 4H2O. The results of spectroscopic (Raman, IR) study of both uranyl silicates and tentative assignment of spectra are given in the paper. Uranyl silicates originated there by weathering of primary uranium minerals in the conditions of supergene zone in-situ. © 2013, National Museum Prague. All right reserved.


Sejkora J.,Mineralogicko petrologicke oddeleni | Babka K.,Na vysluni 1154 | Pavlicek R.,Anglicka 2458
Bulletin Mineralogicko-Petrologickeho Oddeleni Narodniho Muzea v Praze | Year: 2012

A hydrated magnesium uranyl phosphate, mineral saléeite, was found in the dump material of the western part of the Rovnost uranium deposit, the Jáchymov ore district, Krušné hory Mountains, Czech Republic. Saléeite occurs as tiny (up to 0.5 mm) yellow tabular crystals formed small groups and radial aggregates in cavities of ore gangue or yellow irregular agregates and coatings up to 5 mm in gangue fractures. Metatorbernite, brochantite and mineral of the phosphuranylite-dewindtite serie were found in association. Saléeite is monoclinic, space group P21/c, the unit-cell parameters refined from X-ray powder diffraction data are: a 7.018(7), b 19.961(4), c 9.968(7), β 135.27(3) and V 983(2) Å3. Chemical analyses correspond to empirical formula(Mg0.61Ca0.21Fe0.11Cu0.09Pb0.02Zn0.02)Σ1.06 (UO2)2.01 [(PO4)1.51(AsO4)0.46(SiO4)0.03]Σ2.00. 10H2O on the basis (P+As+Si) = 2 apfu. Saléeite originated there by weathering of primary uranium minerals in the conditions of supergene zone in-situ. © 2012, National Museum Prague. All right reserved.


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.


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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