scholarly journals Cu-rich members of the beudantite-segnitite series from the Krupka ore district, the Krušné hory Mountains, Czech Republic

2012 ◽  
pp. 355-371
Author(s):  
J. Sejkora ◽  
J. Škovíra ◽  
J. Čejka ◽  
J. Plášil
Keyword(s):  
Czech Republic ◽  
Krušné Hory Mountains ◽  
Ore District

Pb-Sb zrudnění z Antimonitové žíly, důl Rudolf, Bohutín (Česká republika)

2021 ◽  
Vol 29 (2) ◽  
pp. 275-280
Author(s):  
Pavel Škácha ◽  
Jiří Sejkora
Keyword(s):  
Czech Republic ◽  
Chemical Composition ◽  
Empirical Formula ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Ore District ◽  
Archive Material

The Pb-Sb mineralization with dominant stibnite and plagionite and associated semseyite and zinkenite was found in an archive material collected at the Antimonitová vein, Bohutín, Březové Hory ore district (Czech Republic). Plagionite forms subhedral aggregates up to 1 mm in size. The unit-cell parameters of plagionite for monoclinic space group C2/c refined from the X-ray powder data are: a 13.4890(17), b 11.8670(14), c 19.997(2) Å, β 107.199(8)° and V 3057.9(6) Å3. Its chemical composition (average of 26 analyses, based on 30 apfu) corresponds to the empirical formula Pb5.02Sb8.15S16.82. Associated zinkenite is forming subhedral crystals up to 1 mm in size. Its empirical formula can be expressed as (Cu0.25Ag0.02Fe0.01)Σ0.28Pb9.22Sb22.19S41.31 (average of 26 analyses, based on 73 apfu). Semseyite aggregates have the empirical formula (Pb8.72Fe0.14)8.86Sb8.42S20.73 (average of 11 analyses, based on 38 apfu).

Staročeskéite, Ag0.70Pb1.60(Bi1.35Sb1.35)Σ2.70S6, from Kutná Hora, Czech Republic, a new member of the lillianite homologous series

2018 ◽  
Vol 82 (4) ◽  
pp. 993-1005 ◽  
Author(s):  
Richard Pažout ◽  
Jiří Sejkora
Keyword(s):  
Czech Republic ◽  
Homologous Series ◽  
Electron Probe ◽  
New Mineral ◽  
Orthorhombic Space Group ◽  
Calculated Density ◽  
New Mineral Species ◽  
Reflected Light ◽  
Ore District ◽  
The Ideal

ABSTRACTA new mineral species, staročeskéite, ideally Ag0.70Pb1.60(Bi1.35Sb1.35)Σ2.70S6, has been found at Kutná Hora ore district, Czech Republic. The mineral occurs in the late-stage Bi-mineralization associated with other lillianite homologues (gustavite, terrywallaceite, vikingite, treasurite, eskimoite and Bi-rich andorite-group minerals) and other bismuth sulfosalts (izoklakeite, cosalite and Bi-rich jamesonite) in quartz gangue. The mineral occurs as lath shaped crystals or anhedral grains up to 80 µm × 70 µm, growing together in aggregates up to 200 µm × 150 µm across. Staročeskéite is steel-grey in colour and has a metallic lustre, the calculated density is 6.185 g/cm3. In reflected light staročeskéite is greyish white; bireflectance and pleochroism are weak with greyish tints. Anisotropy is weak to medium with grey to bluish grey rotation tints. Internal reflections were not observed. The empirical formula based on electron probe microanalyses and calculated on 11 apfu is: (Ag0.68Cu0.01)Σ0.69(Pb1.56Fe0.01Cd0.01)Σ1.58(Bi1.32Sb1.37)Σ2.69(S6.04Se0.01)Σ6.05. The ideal formula is Ag0.70Pb1.60(Bi1.35Sb1.35)Σ2.70S6, which requires Ag 7.22, Pb 31.70, Bi 26.97, Sb 15.72 and S 18.39 wt.%, total 100.00 wt.%. Staročeskéite is a member of the lillianite homologous series with N = 4. Unlike gustavite and terrywallaceite, staročeskéite, similarly to lillianite, is orthorhombic, space group Cmcm, with a = 4.2539(8), b = 13.3094(8), c = 19.625(1) Å, V = 1111.1(2) Å3 and Z = 4. The structure of staročeskéite contains four sulfur sites and three metal sites: one pure Pb site and two mixed sites, M1 (0.52Bi + 0.356Ag + 0.124Sb) and M2 (0.601Sb + 0.259Pb + 0.14Bi). The mineral is characterized by the Bi:Sb ratio 1:1 (Bi/(Bi + Sb) = 0.50) and the Ag+ + Bi3+, Sb3+ ↔ 2 Pb2+ substitution (L%) equal to 70%. Thus the mineral lies between two series of the lillianite structures with N = 4, between the lillianite–gustavite series and the andorite series.

scholarly journals Ag-Pb-Sb Sulfosalts and Se-rich Mineralization of Anthony of Padua Mine near Poličany—Model Example of the Mineralization of Silver Lodes in the Historic Kutná Hora Ag-Pb Ore District, Czech Republic

Minerals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 430 ◽  
Author(s):  
Pažout ◽  
Sejkora ◽  
Šrein
Keyword(s):  
Solid Solution ◽  
Czech Republic ◽  
Chemical Element ◽  
Hydrothermal Fluids ◽  
Tectonic Events ◽  
Mineral Phases ◽  
Ore Mineralization ◽  
Ore Mineralogy ◽  
Low Sulfidation ◽  
Ore District

Significant selenium enrichment associated with selenides and previously unknown Ag-Pb-Sb, Ag-Sb and Pb-Sb sulfosalts has been discovered in hydrothermal ore veins in the Anthony of Padua mine near Poličany, Kutná Hora ore district, central Bohemia, Czech Republic. The ore mineralogy and crystal chemistry of more than twenty silver minerals are studied here. Selenium mineralization is evidenced by a) the occurrence of selenium minerals, and b) significantly increased selenium contents in sulfosalts. Identified selenium minerals include aguilarite and selenides naumannite and clausthalite. The previously unknown sulfosalts from Kutná Hora are identified: Ag-excess fizélyite, fizélyite, andorite IV, andorite VI, unnamed Ag-poor Ag-Pb-Sb sulfosalts, semseyite, stephanite, polybasite, unnamed Ag-Cu-S mineral phases and uytenbogaardtite. Among the newly identified sulfides is argyrodite; germanium is a new chemical element in geochemistry of Kutná Hora. Three types of ore were recognized in the vein assemblage: the Pb-rich black ore (i) in quartz; the Ag-rich red ore (ii) in kutnohorite-quartz gangue; and the Ag-rich ore (iii) in milky quartz without sulfides. The general succession scheme runs for the Pb-rich black ore (i) as follows: galena – boulangerite (– jamesonite) – owyheeite – fizélyite – Ag-exces fizélyite – andorite IV – andorite VI – freieslebenite – diaphorite – miargyrite – freibergite. For the Ag-rich red ore (ii) and ore (iii) the most prominent pattern is: galena – diaphorite – freibergite – miargyrite – pyragyrite – stephanite – polybasite – acanthite. The parallel succession scheme progresses from Se-poor to Se-rich phases, i.e., galena – members of galena – clausthalite solid solution – clausthalite; miargyrite – Se-rich miargyrite; acanthite – aguilarite – naumannite. A likely source of selenium is in the serpentinized ultrabasic bodies, known in the area of “silver” lodes in the South of the ore district, which may enable to pre-concentrate selenium, released into hydrothermal fluids during tectonic events. The origin of the studied ore mineralization is primarily bound to the youngest stage of mineralization of the whole ore district, corresponding to the Ag-Sb sequence of the ´eb´ ore type of the Freiberg ore district in Saxony (Germany) and shows mineralogical and geochemical similarities to low-sulfidation epithermal-style Ag-Au mineralization.

scholarly journals Monitoring of recent mass movement activity in anthropogenic slopes of the Krušné Hory Mountains (Czech Republic)

2011 ◽  
Vol 11 (5) ◽  
pp. 1463-1473 ◽  
Author(s):  
J. Burda ◽  
L. Žižka ◽  
J. Dohnal
Keyword(s):  
Czech Republic ◽  
Slope Failure ◽  
Water Saturation ◽  
Mass Movement ◽  
Interdisciplinary Approach ◽  
Open Pit ◽  
Mass Movements ◽  
Slope Failures ◽  
The Czech Republic ◽  
Krušné Hory Mountains

Abstract. Recent mass movements currently comprise one of the main morphogenetic processes in the extensive anthropogenic relief of the foreground of the Krušné Hory Mountains in the Czech Republic. These mass movements result in several types of deep-seated slope failures, depending on the type of movement and the water saturation of the landslide material. This paper presents the results of a detailed geomorphic survey and orthophotograph analysis combined with geodetic monitoring data in an area affected by open-pit coal mining. An interdisciplinary approach has enabled an in-depth review of both the dynamics and development of recent slope failures. The article describes deep-seated landslide complex in this part of the foothills of the Krušné Hory Mountains. At the study site, mass movements occur in thick colluvial mantle and weathered Tertiary claystones. The main factors influencing their development include rainfall culminations, groundwater flowing from the valley of Šramnický Brook and former slope failures. All of the slope failures that have occurred here have originated at former slope failure sites.

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