Pavol Myšľan, Peter Ružička, Martin Števko, Tomáš Mikuš
Garnet skarn mineralization was recently studied at the Trohanka locality near Prakovce (Gemeric Unit, Eastern Slovakia). Ca-skarn forms lenticular bodies in green schist environment. It mainly consists of zonal garnets, pyroxenes, amphiboles and magnetite accumulations. Studied garnets are rich in andradite component (up to 89.95 mol. %) with minor grossular component (6.83 - 39.67 mol. %). Strong oscillatory zoning in andradite is caused by substitution of Fe3+ and Al3+. Most pyroxenes are rich in the hedenbergite component. In some cases, euhedral diopside crystals with marginal transition zones (composed of diopside with lower content of Mg2+ and higher content of Fe2+) were found in hedenbergite matrix. Amphiboles are dominantly represented by ferro-actinolite and ferro-hornblende in association with isolated euhedral crystals of ferro-tschermakite and ferro-pargasite. Indistinct chemical zonality of amphibole euhedral crystals is caused by presence of ferro-pargasite in the central parts and ferro-tschermakite in the peripheral parts of crystals.
{"title":"Mineralogická charakteristika granátického skarnu z lokality Trohanka pri Prakovciach (gemerikum, Slovenská republika)","authors":"Pavol Myšľan, Peter Ružička, Martin Števko, Tomáš Mikuš","doi":"10.46861/bmp.29.230","DOIUrl":"https://doi.org/10.46861/bmp.29.230","url":null,"abstract":"Garnet skarn mineralization was recently studied at the Trohanka locality near Prakovce (Gemeric Unit, Eastern Slovakia). Ca-skarn forms lenticular bodies in green schist environment. It mainly consists of zonal garnets, pyroxenes, amphiboles and magnetite accumulations. Studied garnets are rich in andradite component (up to 89.95 mol. %) with minor grossular component (6.83 - 39.67 mol. %). Strong oscillatory zoning in andradite is caused by substitution of Fe3+ and Al3+. Most pyroxenes are rich in the hedenbergite component. In some cases, euhedral diopside crystals with marginal transition zones (composed of diopside with lower content of Mg2+ and higher content of Fe2+) were found in hedenbergite matrix. Amphiboles are dominantly represented by ferro-actinolite and ferro-hornblende in association with isolated euhedral crystals of ferro-tschermakite and ferro-pargasite. Indistinct chemical zonality of amphibole euhedral crystals is caused by presence of ferro-pargasite in the central parts and ferro-tschermakite in the peripheral parts of crystals.","PeriodicalId":53145,"journal":{"name":"Bulletin Mineralogie Petrologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70599094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Z. Dolníček, Michaela Kotlánová, Rostislav Koutňák
An electron microprobe study of polished sections prepared from a sample of fine-grained sandstone from the locality Slivotín (Ždánice-Hustopeče Formation, Ždánice Unit, Flysch Belt of the Outer Western Carpathians, Czech Republic) allowed to yield in addition to data on chemical composition also the detailed information on in situ textural relationships of individual minerals. During our study, emphasis was given to accessory phases belonging to the translucent heavy mineral fraction. The detrital garnet (Alm36-82Grs2-45Prp2-22Sps0-15) was extensively dissolved and replaced by calcite cement from its margins and along the cracks. Detrital fluorapatite was dissolved in a similar way, however, dissolution episode was followed by growth of authigenic rims composed of carbonate-fluorapatite. Other observed heavy minerals (zircon, chrome spinel, TiO2 phase, monazite, tourmaline) probably remained unaltered by diagenetic processes. The chemical composition of chrome spinels varies mostly between magnesiochromite and chromite, whereas spinel is very rare. The chemical composition of garnets and chrome spinels is comparable with published data from Czech, Polish and Slovak parts of the Flysch Belt of the Western Carpathians, and indicates the primary source of detrital material in rocks of deeper parts of orogen, characterized especially by the presence of catazonal metamorphites and almost lacking volcanic rocks. Redeposition of heavy minerals from older sediments cannot also be ruled out. The pronounced diagenetic alteration of garnet, if not very scarce in the area of Flysch Belt, could help to explain the earlier observations of wide fluctuations of contents of garnet in heavy mineral concentrates.
{"title":"Vliv diagenetických procesů na asociaci těžkých minerálů v pískovcích z lokality Slivotín (ždánická jednotka, flyšové pásmo Vnějších Západních Karpat, Česká republika)","authors":"Z. Dolníček, Michaela Kotlánová, Rostislav Koutňák","doi":"10.46861/bmp.29.027","DOIUrl":"https://doi.org/10.46861/bmp.29.027","url":null,"abstract":"An electron microprobe study of polished sections prepared from a sample of fine-grained sandstone from the locality Slivotín (Ždánice-Hustopeče Formation, Ždánice Unit, Flysch Belt of the Outer Western Carpathians, Czech Republic) allowed to yield in addition to data on chemical composition also the detailed information on in situ textural relationships of individual minerals. During our study, emphasis was given to accessory phases belonging to the translucent heavy mineral fraction. The detrital garnet (Alm36-82Grs2-45Prp2-22Sps0-15) was extensively dissolved and replaced by calcite cement from its margins and along the cracks. Detrital fluorapatite was dissolved in a similar way, however, dissolution episode was followed by growth of authigenic rims composed of carbonate-fluorapatite. Other observed heavy minerals (zircon, chrome spinel, TiO2 phase, monazite, tourmaline) probably remained unaltered by diagenetic processes. The chemical composition of chrome spinels varies mostly between magnesiochromite and chromite, whereas spinel is very rare. The chemical composition of garnets and chrome spinels is comparable with published data from Czech, Polish and Slovak parts of the Flysch Belt of the Western Carpathians, and indicates the primary source of detrital material in rocks of deeper parts of orogen, characterized especially by the presence of catazonal metamorphites and almost lacking volcanic rocks. Redeposition of heavy minerals from older sediments cannot also be ruled out. The pronounced diagenetic alteration of garnet, if not very scarce in the area of Flysch Belt, could help to explain the earlier observations of wide fluctuations of contents of garnet in heavy mineral concentrates.","PeriodicalId":53145,"journal":{"name":"Bulletin Mineralogie Petrologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70598454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jozef Vlasáč, M. Chovan, R. Vojtko, P. Zitnan, T. Mikuš
The Finsterort and Anton vein system is located in the central zone of the Middle Miocene Štiavnica Stratovolcano between Vyhne and Hodruša-Hámre villages. The vein system contains several partial veins and veinlets and has generally NNE - SSW strike with moderate to steep eastward dip. Kinematics of the veins is characterised by older dextral strike-slip movement replaced by younger normal faulting. The mineralization is associated with the normal faults and the veins contain interesting paragenesis of Au-Ag bearing minerals. Minerals of precious metals are represented by argentotetrahedrite-(Zn) and rozhdestvenskayaite-(Zn), Au-Ag alloys, members of polybasite-pearceite and pyrargyrite-proustite solid solutions, acanthite and uytenbogaardtite. Au-Ag mineralization is accompanied by older paragenesis comprising mainly pyrite, galena, sphalerite and chalcopyrite. Besides quartz, carbonates (calcite, siderite and dolomite) are the main gangue minerals.
{"title":"Mineralogy of the Au-Ag mineralization from the Finsterort and Anton vein system, Štiavnické vrchy Mts. (Slovakia)","authors":"Jozef Vlasáč, M. Chovan, R. Vojtko, P. Zitnan, T. Mikuš","doi":"10.46861/bmp.29.255","DOIUrl":"https://doi.org/10.46861/bmp.29.255","url":null,"abstract":"The Finsterort and Anton vein system is located in the central zone of the Middle Miocene Štiavnica Stratovolcano between Vyhne and Hodruša-Hámre villages. The vein system contains several partial veins and veinlets and has generally NNE - SSW strike with moderate to steep eastward dip. Kinematics of the veins is characterised by older dextral strike-slip movement replaced by younger normal faulting. The mineralization is associated with the normal faults and the veins contain interesting paragenesis of Au-Ag bearing minerals. Minerals of precious metals are represented by argentotetrahedrite-(Zn) and rozhdestvenskayaite-(Zn), Au-Ag alloys, members of polybasite-pearceite and pyrargyrite-proustite solid solutions, acanthite and uytenbogaardtite. Au-Ag mineralization is accompanied by older paragenesis comprising mainly pyrite, galena, sphalerite and chalcopyrite. Besides quartz, carbonates (calcite, siderite and dolomite) are the main gangue minerals.","PeriodicalId":53145,"journal":{"name":"Bulletin Mineralogie Petrologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70599316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dalibor Velebil, Jaroslav Hyršl, J. Sejkora, Z. Dolníček
The quantitative study of chemical composition of 42 samples of the tetrahedrite group minerals from 16 deposits in Peru provided new data enabling their detailed classification within this group. The majority of samples are usual members of tetrahedrite group: tennantite-(Zn) (Casapalca, Castrovirreyna, Huanzala, Mundo Nuevo, Palomo, Pasto Bueno, Quiruvilca, Huarón, Morococha), tetrahedrite-(Zn) (Huachocolpa, Julcani, Palomo, Pasto Bueno, San Genaro), tetrahedrite-(Fe) (Julcani, Mercedes, Quiruvilca) and tennantite-(Fe) (Milpo, Pachapaqui, Huampar, Huanzala, Quiruvilca). The recently approved new member of this group tennantite-(Cu) was found in two samples from the Julcani ore district. At sample from the San Genero mine, recently approved argentotetrahedrite-(Zn) and an unnamed new member „argentotennantite-(Fe)“ were determined.
{"title":"Chemismus a klasifikace minerálů skupiny tetraedritu z ložisek v Peru","authors":"Dalibor Velebil, Jaroslav Hyršl, J. Sejkora, Z. Dolníček","doi":"10.46861/bmp.29.321","DOIUrl":"https://doi.org/10.46861/bmp.29.321","url":null,"abstract":"The quantitative study of chemical composition of 42 samples of the tetrahedrite group minerals from 16 deposits in Peru provided new data enabling their detailed classification within this group. The majority of samples are usual members of tetrahedrite group: tennantite-(Zn) (Casapalca, Castrovirreyna, Huanzala, Mundo Nuevo, Palomo, Pasto Bueno, Quiruvilca, Huarón, Morococha), tetrahedrite-(Zn) (Huachocolpa, Julcani, Palomo, Pasto Bueno, San Genaro), tetrahedrite-(Fe) (Julcani, Mercedes, Quiruvilca) and tennantite-(Fe) (Milpo, Pachapaqui, Huampar, Huanzala, Quiruvilca). The recently approved new member of this group tennantite-(Cu) was found in two samples from the Julcani ore district. At sample from the San Genero mine, recently approved argentotetrahedrite-(Zn) and an unnamed new member „argentotennantite-(Fe)“ were determined.","PeriodicalId":53145,"journal":{"name":"Bulletin Mineralogie Petrologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70599491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dolníček (2020) described several occurrences of bog iron (limonite), which according to his article originates in recent streams by chemical precipitation, without the important role of microorganisms on this process. However, similar occurrences of reddish or orange slime, frequently accompanied by oil-like films floating on the water, are according to many papers ascribed to the biogenic iron oxidation by bacteria. To solve the origin of such precipitates, we have sampled similar materials in four places near Ostrava - Hrabová, two close to Řepiště and Staříč, and also two sites in the vicinity of Hulín investigated by Dolníček (2020). In all cases, scanning electron microscopy of dried samples at the low vacuum (ca 50 Pa) revealed a dominant share of tubular sheaths of the Leptothrix-Sphaerotilus group of bacteria. The prevailing diameter of 1.5 to 1 μm should point to genus Leptothrix, while those with a diameter up to 2.5 μm (genus Sphaerotilus) are far less common. Spiral chains of Gallionella were recognized in all samples, as well as rare pennate diatoms. Space between bacterial filaments is predominantly filled with densely stacked particles micrometer to submicrometer in size, sometimes with oval, fibrous, or tabular shape. It might be both decomposed material of previously mentioned genera and some other small-sized bacteria. Energy-dispersive spectroscopy shows dominant content of iron and oxygen, with a minor admixture of Si, Ca, Al, and P. Powder X-ray diffraction of such microbial mats is showing clastic admixtures (quartz, feldspar group minerals, illite-muscovite, and kaolinite) and two broad low-intensity peaks of ferrihydrite. Only sample D from Řepiště locality shows an absence of ferrihydrite and the presence of hematite and magnetite and/or maghemite. Therefore, we demonstrated that bacterially-induced precipitation plays a major role in the genesis of such recent bog iron occurrences and there are ways how to characterize such material by both biological and mineralogical procedures.
{"title":"Nepodceňujme mikrobiální precipitaci oxihydroxidů železa a manganu v životním prostředí","authors":"D. Matýsek, J. Jirásek","doi":"10.46861/bmp.29.115","DOIUrl":"https://doi.org/10.46861/bmp.29.115","url":null,"abstract":"Dolníček (2020) described several occurrences of bog iron (limonite), which according to his article originates in recent streams by chemical precipitation, without the important role of microorganisms on this process. However, similar occurrences of reddish or orange slime, frequently accompanied by oil-like films floating on the water, are according to many papers ascribed to the biogenic iron oxidation by bacteria. To solve the origin of such precipitates, we have sampled similar materials in four places near Ostrava - Hrabová, two close to Řepiště and Staříč, and also two sites in the vicinity of Hulín investigated by Dolníček (2020). In all cases, scanning electron microscopy of dried samples at the low vacuum (ca 50 Pa) revealed a dominant share of tubular sheaths of the Leptothrix-Sphaerotilus group of bacteria. The prevailing diameter of 1.5 to 1 μm should point to genus Leptothrix, while those with a diameter up to 2.5 μm (genus Sphaerotilus) are far less common. Spiral chains of Gallionella were recognized in all samples, as well as rare pennate diatoms. Space between bacterial filaments is predominantly filled with densely stacked particles micrometer to submicrometer in size, sometimes with oval, fibrous, or tabular shape. It might be both decomposed material of previously mentioned genera and some other small-sized bacteria. Energy-dispersive spectroscopy shows dominant content of iron and oxygen, with a minor admixture of Si, Ca, Al, and P. Powder X-ray diffraction of such microbial mats is showing clastic admixtures (quartz, feldspar group minerals, illite-muscovite, and kaolinite) and two broad low-intensity peaks of ferrihydrite. Only sample D from Řepiště locality shows an absence of ferrihydrite and the presence of hematite and magnetite and/or maghemite. Therefore, we demonstrated that bacterially-induced precipitation plays a major role in the genesis of such recent bog iron occurrences and there are ways how to characterize such material by both biological and mineralogical procedures.","PeriodicalId":53145,"journal":{"name":"Bulletin Mineralogie Petrologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70598609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Crystalline limestones containing fragments of amphibolites from the locality Dobšiná - Kruhová are part of the Klátov complex (Northern Gemericum, Western Carpathians). The colour of studied rocks is light grey with massive texture and granoblastic structure. Inhomogeneous mottled to breccia-like character of a crystalline limestones is caused by the presence of amphiboles in the studied rocks. The identified mineral association of crystalline limestones consists of calcite, amphiboles (pargasite, magnesio-hornblende, actinolite), clinopyroxenes (diopside), albite and titanite. Chemical zonation of amphiboles from the crystalline limestones and fragments of amphibolites have been studied in BSE imaging. Light grey BSE zone is represented by pargasite (with more Fe2+ up to 1.37 apfu and less Mg up to 2.26 apfu) and dark grey BSE zone is represented by magnesio-hornblend and actinolite (less Fe2+ 0.68 apfu in magnesio-hornblende; 0.62 apfu in actinolite and more Mg up to 3.30 apfu in magnesio-hornblende and up to 4.03 apfu in actinolite). Diopside has slightly higher content of Al (up to 0.13 apfu) and low content of Fe2+ (up to 0.17 apfu) with XMg ratio in the range 0.83 - 0.96. Chemical composition of albites is Ab91.12-98.21An1.52-5.12 with ortoclase component in the range 0.22 - 4.49 mol. %. Titanites from the amphibolite fragments and crystalline limestones have identical chemical composition (Ca up do 1.00 apfu, Si up to 0.97 apfu). Lower content of Ti (0.88 - 0.95 apfu) and higher content of F (up to 0.27 wt. %) and H2O (up to 0.38 wt. %) is present. In titanites not very significant (Al, Fe3+) + (OH, F) ↔ Ti + O substitution was also identified. We assume that pargasite and magnesio-hornblende are products of prograde etape of metamorphosis unlike actinolite which is product of retrograde etape of metamorphosis. Diopside was generated by dehydration and decomposition processes of magnesio-hornblende and pargasite in a high-temperature prograde regime of metamorphosis in the conditions of upper amphibolite facies. Calcite is chemically pure, presence of dolomite has not been confirmed.
{"title":"Minerálne zloženie kryštalických vápencov z lokality Dobšiná - Kruhová (Slovenská republika)","authors":"Peter Ružička, Pavol Myšľan, Tomáš Mikuš","doi":"10.46861/bmp.29.285","DOIUrl":"https://doi.org/10.46861/bmp.29.285","url":null,"abstract":"Crystalline limestones containing fragments of amphibolites from the locality Dobšiná - Kruhová are part of the Klátov complex (Northern Gemericum, Western Carpathians). The colour of studied rocks is light grey with massive texture and granoblastic structure. Inhomogeneous mottled to breccia-like character of a crystalline limestones is caused by the presence of amphiboles in the studied rocks. The identified mineral association of crystalline limestones consists of calcite, amphiboles (pargasite, magnesio-hornblende, actinolite), clinopyroxenes (diopside), albite and titanite. Chemical zonation of amphiboles from the crystalline limestones and fragments of amphibolites have been studied in BSE imaging. Light grey BSE zone is represented by pargasite (with more Fe2+ up to 1.37 apfu and less Mg up to 2.26 apfu) and dark grey BSE zone is represented by magnesio-hornblend and actinolite (less Fe2+ 0.68 apfu in magnesio-hornblende; 0.62 apfu in actinolite and more Mg up to 3.30 apfu in magnesio-hornblende and up to 4.03 apfu in actinolite). Diopside has slightly higher content of Al (up to 0.13 apfu) and low content of Fe2+ (up to 0.17 apfu) with XMg ratio in the range 0.83 - 0.96. Chemical composition of albites is Ab91.12-98.21An1.52-5.12 with ortoclase component in the range 0.22 - 4.49 mol. %. Titanites from the amphibolite fragments and crystalline limestones have identical chemical composition (Ca up do 1.00 apfu, Si up to 0.97 apfu). Lower content of Ti (0.88 - 0.95 apfu) and higher content of F (up to 0.27 wt. %) and H2O (up to 0.38 wt. %) is present. In titanites not very significant (Al, Fe3+) + (OH, F) ↔ Ti + O substitution was also identified. We assume that pargasite and magnesio-hornblende are products of prograde etape of metamorphosis unlike actinolite which is product of retrograde etape of metamorphosis. Diopside was generated by dehydration and decomposition processes of magnesio-hornblende and pargasite in a high-temperature prograde regime of metamorphosis in the conditions of upper amphibolite facies. Calcite is chemically pure, presence of dolomite has not been confirmed.","PeriodicalId":53145,"journal":{"name":"Bulletin Mineralogie Petrologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70598962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An interesting ore mineralization containing Pb-Bi minerals, present in a thin layer parallel with schistosity of the host amphibolite, was newly recognized in the Libodřice quarry near Kolín (Kutná Hora Crystalline Complex, Czech Republic). The disseminations of ore minerals are formed especially by pyrrhotite and chalcopyrite, less pyrite and accessory galena, native bismuth, cosalite, bismuthinite and joséite-B. The equilibrium textural relationships of rock-forming silicates and main sulphides indicate that the ore assemblage underwent metamorphic recrystallization together with the host rock, however, indications of younger local re-equilibrations under changed physico-chemical conditions (especially temperature, fugacity of sulphur, fugacity of oxygen) were also observed. The presence of polysynthetic lamellae in chalcopyrite suggests for its origin/re-crystallization at temperatures above 550 °C. Sporadic cosalite, stable at temperatures below 425 °C, was probably precursor of pseudomorphs today formed by galena and native bismuth. Pseudomorphs originated at temperatures below 271 °C probably due to local decrease of sulphur fugacity caused by growth of associated pyrrhotite. The local sulphurisation of small amount of native bismuth to bismuthinite and small part of pyrrhotite to pyrite finished the process of ore evolution. The presence of elevated contents of Te, Se and Ni in the studied mineralization confirms the source of these elements in the host rock environment, which was presupposed on the basis of earlier mineralogical study of Alpine-type veins in the area of the Kutná Hora Crystalline Complex.
{"title":"Pb-Bi mineralizace v amfibolitech z lomu Libodřice u Kolína (kutnohorské krystalinikum, Česká republika)","authors":"Z. Dolníček, Jana Ulmanová","doi":"10.46861/bmp.29.006","DOIUrl":"https://doi.org/10.46861/bmp.29.006","url":null,"abstract":"An interesting ore mineralization containing Pb-Bi minerals, present in a thin layer parallel with schistosity of the host amphibolite, was newly recognized in the Libodřice quarry near Kolín (Kutná Hora Crystalline Complex, Czech Republic). The disseminations of ore minerals are formed especially by pyrrhotite and chalcopyrite, less pyrite and accessory galena, native bismuth, cosalite, bismuthinite and joséite-B. The equilibrium textural relationships of rock-forming silicates and main sulphides indicate that the ore assemblage underwent metamorphic recrystallization together with the host rock, however, indications of younger local re-equilibrations under changed physico-chemical conditions (especially temperature, fugacity of sulphur, fugacity of oxygen) were also observed. The presence of polysynthetic lamellae in chalcopyrite suggests for its origin/re-crystallization at temperatures above 550 °C. Sporadic cosalite, stable at temperatures below 425 °C, was probably precursor of pseudomorphs today formed by galena and native bismuth. Pseudomorphs originated at temperatures below 271 °C probably due to local decrease of sulphur fugacity caused by growth of associated pyrrhotite. The local sulphurisation of small amount of native bismuth to bismuthinite and small part of pyrrhotite to pyrite finished the process of ore evolution. The presence of elevated contents of Te, Se and Ni in the studied mineralization confirms the source of these elements in the host rock environment, which was presupposed on the basis of earlier mineralogical study of Alpine-type veins in the area of the Kutná Hora Crystalline Complex.","PeriodicalId":53145,"journal":{"name":"Bulletin Mineralogie Petrologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70597903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Martin Števko, Peter Tóth, Filip Lednický, Jiří Sejkora, Zdeněk Dolníček
A new occurrence of mimetite was recently discovered at the abandoned Ján Nepomuk Pb-Ag deposit near Veľké Pole, Žarnovica Co., Banská Bystrica Region, Slovakia. It forms light to bright yellow, prismatic crystals reaching up to 5 mm in size. Mimetite occurs in fractures and cavities of strongly altered and limonitised limestone with impregnations and relicts of primary galena and pyrite. It is associated with cerussite and calcite. The refined unit-cell parameters (for the hexagonal space group P63/m) are a 10.2437(4) Å, c 7.4437(6) Å and V 676.44(6) Å3. Except of dominant contents of Pb, As and Cl only minor amounts of Ca (up to 0.36 apfu), Al (up to 0.03 apfu), P (up to 0.03 apfu) and V (up to 0.02 apfu) were detected in four mimetite samples studied by EMPA-WDS.
{"title":"Mimetit z ložiska Ján Nepomuk pri Veľkom Poli (Slovenská republika)","authors":"Martin Števko, Peter Tóth, Filip Lednický, Jiří Sejkora, Zdeněk Dolníček","doi":"10.46861/bmp.29.001","DOIUrl":"https://doi.org/10.46861/bmp.29.001","url":null,"abstract":"A new occurrence of mimetite was recently discovered at the abandoned Ján Nepomuk Pb-Ag deposit near Veľké Pole, Žarnovica Co., Banská Bystrica Region, Slovakia. It forms light to bright yellow, prismatic crystals reaching up to 5 mm in size. Mimetite occurs in fractures and cavities of strongly altered and limonitised limestone with impregnations and relicts of primary galena and pyrite. It is associated with cerussite and calcite. The refined unit-cell parameters (for the hexagonal space group P63/m) are a 10.2437(4) Å, c 7.4437(6) Å and V 676.44(6) Å3. Except of dominant contents of Pb, As and Cl only minor amounts of Ca (up to 0.36 apfu), Al (up to 0.03 apfu), P (up to 0.03 apfu) and V (up to 0.02 apfu) were detected in four mimetite samples studied by EMPA-WDS.","PeriodicalId":53145,"journal":{"name":"Bulletin Mineralogie Petrologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70598349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Sejkora, P. Pauliš, M. Urban, Z. Dolníček, Jana Ulmanová, Ondřej Pour
An extraordinary rich mineral assemblage (more than 35 determined mineral species) has been discovered in quartz greisen mineralization found at dump material of the abandoned Mauritius mine. This mine is situated about 1 km N of the Hřebečná village, 16 km N of Karlovy Vary, Krušné hory Mountains, Czech Republic. The studied mineralization with its textural and mineralogical character differs significantly from the usual fine-grained greisens mined in this area. The primary mineralization is represented by coarse-grained quartz and fluorapatite with sporadic zircon, monazite-(Ce), xenotime-(Y) and very rare cassiterite. Besides common sulphides (arsenopyrite, chalcopyrite, pyrite, sphalerite, tetrahedrite-group minerals), Bi-sulphosalts (aikinite, bismuthinite, berryite, cuprobismutite, emplectite, wittichenite) were determined. Members of the tetrahedrite group also contain increased amounts of Bi - in addition to Bi-rich tennantite-(Zn) and tennantite-(Fe), microscopic zones represented by the not approved Bi-dominant analogue of tennantite („annivite-(Zn)“) were also found. The primary mineralization was intensively affected by supergene processes. Chalcopyrite and sphalerite are replaced by Cu sulphides - especially anilite and digenite, and more rarely by geerite, spionkopite and covellite. Some of the fluorapatite grains in the vein quartz were decomposed and mrázekite, mixite, libethenite, pseudomalachite, hydroxylpyromorphite, metatorbernite as well as rare dzhalindite crystallized in the resulting cavities. However, the most abundant supergene phases are the minerals of the alunite supergroup - crandallite, goyazite, plumbogummite, svanbergite and waylandite. The detailed descriptions, X-ray powder diffraction data, refined unit-cell parameters and quantitative chemical composition of individual studied mineral phases are presented.
{"title":"Mineralogie křemenných žil ložiska cínových rud Hřebečná u Abertam v Krušných horách (Česká republika)","authors":"J. Sejkora, P. Pauliš, M. Urban, Z. Dolníček, Jana Ulmanová, Ondřej Pour","doi":"10.46861/bmp.29.131","DOIUrl":"https://doi.org/10.46861/bmp.29.131","url":null,"abstract":"An extraordinary rich mineral assemblage (more than 35 determined mineral species) has been discovered in quartz greisen mineralization found at dump material of the abandoned Mauritius mine. This mine is situated about 1 km N of the Hřebečná village, 16 km N of Karlovy Vary, Krušné hory Mountains, Czech Republic. The studied mineralization with its textural and mineralogical character differs significantly from the usual fine-grained greisens mined in this area. The primary mineralization is represented by coarse-grained quartz and fluorapatite with sporadic zircon, monazite-(Ce), xenotime-(Y) and very rare cassiterite. Besides common sulphides (arsenopyrite, chalcopyrite, pyrite, sphalerite, tetrahedrite-group minerals), Bi-sulphosalts (aikinite, bismuthinite, berryite, cuprobismutite, emplectite, wittichenite) were determined. Members of the tetrahedrite group also contain increased amounts of Bi - in addition to Bi-rich tennantite-(Zn) and tennantite-(Fe), microscopic zones represented by the not approved Bi-dominant analogue of tennantite („annivite-(Zn)“) were also found. The primary mineralization was intensively affected by supergene processes. Chalcopyrite and sphalerite are replaced by Cu sulphides - especially anilite and digenite, and more rarely by geerite, spionkopite and covellite. Some of the fluorapatite grains in the vein quartz were decomposed and mrázekite, mixite, libethenite, pseudomalachite, hydroxylpyromorphite, metatorbernite as well as rare dzhalindite crystallized in the resulting cavities. However, the most abundant supergene phases are the minerals of the alunite supergroup - crandallite, goyazite, plumbogummite, svanbergite and waylandite. The detailed descriptions, X-ray powder diffraction data, refined unit-cell parameters and quantitative chemical composition of individual studied mineral phases are presented.","PeriodicalId":53145,"journal":{"name":"Bulletin Mineralogie Petrologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70598373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An interesting occurrence of olivenite and cornwallite was recently discovered in cavities of quartz at the Podlipa copper deposit near Ľubietová, Slovakia. Olivenite occurs as olive to pale green sprays or radial aggregates consisting of individual acicular crystals up to 5 mm long. Its refined unit-cell parameters (for the monoclinic space group P21/n) are: a 8.6192(13) Å, b 8.2300(11) Å, c 5.9349(8) Å, α 90.055(12)° and V 420.99(7) Å3. Studied olivenite shows intense chemical zoning caused by strong variation of As and P contents. Most of the zones are corresponding to olivenite (with P content ranging between 0.02 to 0.39 apfu), but darker zones or domains of As-rich libethenite (with As content ranging between 0.18 to 0.24 apfu) were occasionally observed. Cornwallite forms dark green massive fillings between olivenite crystals or microcrystalline botryoidal crusts. The refined unit-cell parameters (for the monoclinic space group P21/c) of botryoidal cornwallite from the Podlipa deposit are: a 4.6112(2) Å, b 5.7698(3) Å, c 17.4167(11) Å, β 92.009(5)° and V 463.10(3) Å3. The two compositional types of cornwallite were distinguished. The first type is represented by relatively homogenous aggregates with only minor contents of P (from 0.04 to 0.22 apfu). The second type occurs as polycrystalline fillings with strong chemical zoning and has much more significant variation of As and P contents, representing solid-solution series between P-rich cornwallite (with 1.41 apfu of As and 0.59 apfu of P) and As-rich pseudomalachite (with 1.37 apfu of P and 0.63 apfu of As).
{"title":"Olivenite and cornwallite from the Podlipa copper deposit near Ľubietová, Slovakia","authors":"M. Števko, J. Sejkora, Z. Dolníček","doi":"10.46861/bmp.29.189","DOIUrl":"https://doi.org/10.46861/bmp.29.189","url":null,"abstract":"An interesting occurrence of olivenite and cornwallite was recently discovered in cavities of quartz at the Podlipa copper deposit near Ľubietová, Slovakia. Olivenite occurs as olive to pale green sprays or radial aggregates consisting of individual acicular crystals up to 5 mm long. Its refined unit-cell parameters (for the monoclinic space group P21/n) are: a 8.6192(13) Å, b 8.2300(11) Å, c 5.9349(8) Å, α 90.055(12)° and V 420.99(7) Å3. Studied olivenite shows intense chemical zoning caused by strong variation of As and P contents. Most of the zones are corresponding to olivenite (with P content ranging between 0.02 to 0.39 apfu), but darker zones or domains of As-rich libethenite (with As content ranging between 0.18 to 0.24 apfu) were occasionally observed. Cornwallite forms dark green massive fillings between olivenite crystals or microcrystalline botryoidal crusts. The refined unit-cell parameters (for the monoclinic space group P21/c) of botryoidal cornwallite from the Podlipa deposit are: a 4.6112(2) Å, b 5.7698(3) Å, c 17.4167(11) Å, β 92.009(5)° and V 463.10(3) Å3. The two compositional types of cornwallite were distinguished. The first type is represented by relatively homogenous aggregates with only minor contents of P (from 0.04 to 0.22 apfu). The second type occurs as polycrystalline fillings with strong chemical zoning and has much more significant variation of As and P contents, representing solid-solution series between P-rich cornwallite (with 1.41 apfu of As and 0.59 apfu of P) and As-rich pseudomalachite (with 1.37 apfu of P and 0.63 apfu of As).","PeriodicalId":53145,"journal":{"name":"Bulletin Mineralogie Petrologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70598545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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