rss_2.0Mineralogia FeedSciendo RSS Feed for Mineralogia Feed transfer and element redistribution during chloritization of metamorphic biotite in a metapelite: insights from compositional mapping<abstract> <title style='display:none'>Abstract</title> <p>Fluid-driven reactions are common in the upper crust, leading to mineral replacement and element redistribution on a kilometer to a micron scale. One common fluid-induced reaction is the chloritization of biotite. Chloritization can lead to the production of multiple phases, such as K-feldspar, titanite, and rutile, depending on local chemistry and fluid composition. Here, we compare different approaches to mass balance calculations using an altered garnet-bearing metapelite collected from Ny Friesland, Svalbard Archipelago, Norway. In the outcrop, amphibolite facies schists are cut by joints that acted as fluid pathways that led to the development of a narrow (~5 cm) alteration zone. Alteration involved the replacement of biotite by chlorite + K-feldspar ± rutile ± titanite. Mass balance calculations based on whole-rock composition and assuming immobile Zr indicate the addition of H<sub>2</sub>O, Si, Ti, Fe, or Mg and the removal of K or Ca. In contrast, mass balance calculated for the pseudomorphic replacement of Bt by Chl + Kfs ± Rt ± Ttn using X-Ray maps for three focused areas indicates the removal of Si or Ti rather than addition. Moles of product phase and elements gained or lost during this reaction varies between individual areas. This variation suggests that fluid heterogeneity and local chemistry governed the progression of the replacement reaction. All the product phases involved in the biotite breakdown are geochronometers and/or geothermometers, providing new opportunities for the petrochronology of fluid-induced reactions.</p> </abstract>ARTICLEtrue zeolite derived from coal fly ash decorated with magnetic alginate bead: Application to detoxification of arsenic and vanadium<abstract> <title style='display:none'>Abstract</title> <p>Heavy metal toxicity is highly demanding and challenging to clean up the pollutants. To recover the issues mentioned above, we propose a hydrothermal synthesis of zeolite (NaX-UP). Further surface modification by poly-ethylenimine (PEI) could turn to be amine-modified zeolite nanosheets (zeolite NSs) possessed plenty of hydroxyl and amino groups (Al-O, Si-O-Si, Si-OH and NH<sub>2</sub>) on their surface, decorated with magnetic nanoparticles (Fe<sub>3</sub>O<sub>4</sub> NPs), that are enabled to bridge with inter and intramolecular hydrogen bonding an additionally electrostatic interaction might be a significant role. Further, this can be converted into magnetic bead crosslinking with sodium alginate immersed in an excess calcium chloride solution. The-as formed Fe<sub>3</sub>O<sub>4</sub> NPs decorated amine modified zeolite alginate bead denoted to be (Fe<sub>3</sub>O<sub>4</sub> NPs decorated @PEI-zeolite NSs alginate bead) upholding a significant advantage would aim to clean up the anionic pollutants are [As(V) &amp; V(V)] from an aqueous solution.</p> </abstract>ARTICLEtrue dolomitic marble-hosted talc from the Mulvoj area in the Western Pamir Mountains, Tajikistan<abstract> <title style='display:none'>Abstract</title> <p>Talc is crystallized in the metamorphic dolomitic rocks of the southwest Pamir mountains in the Mulvoj area, Tajikistan. Field studies show that talc is restricted to metamorphic dolomitic marble layers in the garnet-mica schist and gneiss. The layers are parallel to the original sedimentary bedding and schistosity of the metamorphic rocks. Petrography and whole rock geochemistry reveal calcite, tremolite, quartz and dolomite as the main mineral phases in the talc-bearing metamorphosed dolomitic rocks, while calcite is absent in the samples without talc. XRD studies show that talc samples are almost pure, and geochemistry indicates very low Fe and Cr and very high Mg contents. Geochemical features along with field observations clearly shows that Mulvoj talc is not originated from peridotite. Based on phase relations studies in the CaO-MgO-SiO<sub>2</sub>-H<sub>2</sub>O-CO<sub>2</sub> system, the reaction between dolomite, quartz, and water at pressure greater than 2 kbar and temperature up to ~460°C and X<sub>CO2</sub> up to 0.6 was the main talc forming reaction. Talc and calcite consuming reaction produced tremolite, dolomite and binary (CO<sub>2</sub>-H<sub>2</sub>O) fluid.</p> </abstract>ARTICLEtrue – history and present<abstract> <title style='display:none'>Abstract</title> <p>The authors present the history of chrysoprase discovery and the progress of knowledge about this material over the millennia, based on the extended review of world literature. Tracing the oldest archaeological artifacts from before 9,000 years, the lens of history turns on a stone that has not been properly identified mineralogically for centuries. In the 1830s, chrysoprase was finally included into the chalcedony group and its green color was associated, very correctly, with nickel compounds dispersed in its structure. After all, the most current mineralogy of chrysoprase is presented on the basis of the results of modern analytical studies. These data clearly indicate that chrysoprase is a mixture of several SiO<sub>2</sub> polymorphs with varying degrees of structural order (opal, chalcedony, moganite, quartz). This radically changes the previous taxonomy of chrysoprase and its position in current mineralogical and petrographic systematics.</p> </abstract>ARTICLEtrue from the metaluminous granite of SW Egypt<abstract> <title style='display:none'>Abstract</title> <p>Optical microscopy and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) analyses were used to characterize britholite-(Ce) of the metaluminous granite (Proterozoic) intruded into the Nubian Formation in southwestern Egypt and having a relatively high content of radioactive elements (potassium = 4.4 wt%, thorium = 52 ppm, uranium = 10 ppm). The britholite-(Ce) studied here incorporates light rare earth elements (LREE) including lanthanum, cerium, praseodymium, and neodymium as well as thorium. The mineral forms as tabular crystals in a fine-grained quartz-K-feldspar-plagioclase matrix, coexisting with other accessory minerals including biotite, zircon, clinochlore, titanite, and magnetite. Primary britholite-(Ce) usually includes titanite, zircon, and magnetite and is occasionally included in biotite. The inclusion of britholite-(Ce) in biotite suggests that the two minerals crystallized approximately coevally. Petrographical and SEM-EDS data indicate breakdown of the primary magmatic britholite-(Ce) in the samples. This study constitutes the first report for a sole presence of britholite-(Ce) as LREE phase in metaluminous granite samples from Egypt.</p> </abstract>ARTICLEtrue risk assessment in the vicinity of a copper smelter: particulate matter collected on a spider web<abstract> <title style='display:none'>Abstract</title> <p>We used spider webs as a particulate matter (PM) sampler to assess the possible health risk to the inhabitants of Legnica city (Poland). We aimed to find out if it is a useful material and could provide reliable information. We selected two spider families (Agelenidae and Linyphiidae) whose webs structure enhances the PM accumulation. The collected particles were analysed using a Scanning Electron Microscope equipped with Energy Dispersive X-Ray (SEM-EDX) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) which provided morphological and chemical information and allowed to indicate possible sources of pollution. The results showed that PM<sub>10</sub>, the fraction of particles smaller than 10 µm, was dominated by the particles of natural origin, while fine fractions were composed of diverse anthropogenic particles, whose origin can be connected with the activity of the copper smelter and in smaller quantity with the road traffic. The carcinogenic and non-carcinogenic health risk was assessed for these pathways: inhalation, ingestion, and dermal, for children and adults. The non-carcinogenic risk was very high (Hazard Index: HI &gt; 1) both for children (Cu, Ni, Pb, Cd) and adults (Cu, As, Pb, Cd). Moreover, high carcinogenic risk (&gt;10<sup>-4</sup>) was found in most of the sampling points. The study shows that spider webs are useful in biomonitoring of PM and can also be used for health risk assessment. In the studied region, it was found that the possible negative impact of air pollution on human health exists.</p> </abstract>ARTICLEtrue temperature transformation of iron-bearing minerals in basalt: Mössbauer spectroscopy studies<abstract> <title style='display:none'>Abstract</title> <p>The high temperature decomposition of basalt from Lower Silesia (Poland) was followed by Mössbauer spectroscopy investigation. The Fe content of the sample was ~9.0 at.%. The X-ray diffraction analysis shows that augite (37%) and olivine (12%) are major Fe-bearing mineral components. The sample also contains significant amount of anorthite (22%) and nepheline (17%). The sample was heated at various temperatures between 200°C and 1100°C for three hours. Up to a temperature of 500°C changes in contribution of Fe-bearing minerals are insignificant. Heating in the temperature range from 500°C to 1100°C leads to a systematic increase in contribution of iron oxides at the cost of contribution of silicate minerals, like augite and olivine. Mössbauer spectrum obtained after heating at 1100°C showed hematite as the main iron oxide phase. The ratio of Fe<sup>3+</sup>/Fe<sub>tot</sub> in the non-heated sample was equal to 0.51 and after heating at 1100°C this ratio amounted to 0.89.</p> </abstract>ARTICLEtrue and geochemical evidence for two-stage silicification of serpentinized peridotites from the Szklary Massif (NE Bohemian Massif)<abstract> <title style='display:none'>Abstract</title> <p>Previously unknown exposures of silicified serpentinites have been documented within the Szklary Massif, which is a fragment of the tectonically dismembered Central Sudetic Ophiolite (NE Bohemian Massif). On the basis of textural, mineralogical and chemical differences, two types of silicified serpentinites have been distinguished in this study (Type I and Type II). Type I is characterized by well-preserved primary minerals cut by numerous veinlets filled with microscale euhedral quartz crystals. Studied samples of Type I are enriched in silica (from 62 to 69 wt.% SiO<sub>2</sub>) and depleted in magnesium (from 10 to 19 wt.% MgO) in comparison to serpentinized peridotites from the Szklary Massif. Type II is almost exclusively composed of amorphous or poorly crystalline silica, with microquartz aggregates being the most abundant form. Silicified serpentinites of Type II show extremely high values of silica (from 83 to 90 wt.% SiO<sub>2</sub>) and low magnesium concentrations (from 4 to 8 wt.% MgO). Both types of silicified serpentinites have elevated content of REE and many other trace elements generally regarded as incompatible. We infer that the earlier silicification event was caused by the percolation of Si-rich hydrothermal fluids derived from igneous rocks, which intruded this area from ca. 380 to 330 Ma. A subsequent silicification event is the result of silica remobilization during intense chemical weathering under tropical conditions, which could have occurred between Late Cretaceous and Miocene.</p> </abstract>ARTICLEtrue A mineral formula recalculation and plotting program for electron probe microanalysis<abstract> <title style='display:none'>Abstract</title> <p>MinPlot is a MATLAB®-based mineral formula recalculation and compositional plotting program for electron microprobe analyses (EPMA). The program offers recalculation and structural formula assignment for 15 different mineral groups: Garnet, pyroxene, olivine, amphibole, feldspar, mica, staurolite, cordierite, chlorite, chloritoid, talc, epidote, titanite, spinel, and sulfides. MinPlot is a fast and easy to use command line program and requires no prior computer programming knowledge. Percent mass fractions of oxides are loaded from datafiles and the user answers simple prompts to select mineral type, normalization scheme, and plotting options. Recalculated mineral formulas are automatically saved as output files and plots may be further manually customized by the user prior to saving. MinPlot can perform thousands of calculations in seconds and the modular nature of the program makes it simple to add new calculation routines in future releases. Combined, these features make MinPlot a powerful and useful program for the processing of EPMA data.</p> </abstract>ARTICLEtrue Devonian sinistral shearing recorded by retrograde monazite-(Ce) in Oscar II Land, Svalbard<abstract> <title style='display:none'>Abstract</title> <p>The Southwestern Basement Province of Svalbard extends northward from Sørkapp Land in the south to Oscar II Land. In the north, the Müllerneset Formation characterized by polymetamorphosed Proterozoic sedimentary rocks crops out. In this study we used an integrated tectonic and petrochronological approach to gain an insight into the structural and metamorphic evolution of the unit and surrounding basement. The Müllerneset Formation consists of two separate tec-tonic blocks. NNW-SSE trending retrograde foliation is associated with mineral and stretching lineation and kinematic indicators consistent with left-lateral to oblique sinistral shearing in the western block. The eastern block is characterized by the opposite sense of shear that was overturned during the Eurekan event as evidenced by unconformably overlaying Carboniferous sedimentary rocks. Conventional geothermobarometry yields the prograde peak pressure metamorphic conditions of 6.6 - 7.1 kbar at 480 - 520°C followed by peak temperature at 5.1 - 5.9 kbar and 530 - 560°C. Subsequent retrograde greenschist facies overprint is related to left-lateral NNW-SSE trending shearing. Tiny monazite occurs within foliation or overgrows allanite-(Ce), thus is interpreted as growth along a retrograde path. Th-U-total Pb dating of monazite-(Ce) provided an early Caledonian age (ca. 450 Ma) and younger population of ca. 410 ± 8 Ma. This age is consistent with previously reported <sup>40</sup>Ar/<sup>39</sup>Ar cooling ages (410 ± 2 Ma) of muscovite supporting a retrograde growth of monazite. Petrochronological evidence combined with structural observations suggests that the Müllerneset Formation has been tectonically exhumed in the Early Devonian due to the NNW-SSE trending left-lateral shearing. Coeval folding and thrusting in the remaining basement of Oscar II Land to the east indicate a transpressional regime of the deformation in the Early Devonian. Similarly oriented contemporaneous tectonic zones within the Southwestern Basement Province of Svalbard may account for the same set of shear zones dispersing the Ordovician subduction complexes along western Spitsbergen.</p> </abstract>ARTICLEtrue melt and fluid inclusions in garnet from the Kangerlussuaq basement, Southeast Greenland<abstract> <title style='display:none'>Abstract</title> <p>The present work reports the first anatectic melt inclusions found so far in the Mesoarchean basement in East Greenland. Using optical microscope observations and MicroRaman spectroscopy, we show that garnets in metasedimentary migmatite contain primary polycrystalline aggregates which can be confidently interpreted as former droplets of anatectic melt, i.e. nanogranitoids. In some cases, they coexist with coeval fluid inclusions under conditions of primary fluid-melt immiscibility. The re-evaluation of the metamorphic pressure and temperature conditions with up-to-date phase equilibria modelling, combined with the identification of nanogranitoids and fluid inclusions, suggests metamorphic peak equilibration and partial melting in presence of a COH-fluid at T ~1000°C and P &gt; 7 kbar. To date, this is the oldest verified occurrence of nanogranitoids and fluid-melt immiscibility during garnet growth in a partially molten environment.</p> </abstract>ARTICLEtrue immobilization of Zn, Pb and Cd by additives to highly contaminated soils<abstract> <title style='display:none'>Abstract</title> <p>The immobilization effect of soil amendments on leaching and bioavailability of Pb, Zn and Cd in highly contaminated soils under industrial impact was studied by collecting the soils in the surroundings of Zn-Pb Smelter “Miasteczko Śląskie” in southern Poland as an example. Various amounts of four additives (phosphate fertilizer, limestone powder, bentonite rock and bog iron ore) were tested in laboratory experiments to compare the effectiveness of three dominant mechanisms of immobilization: precipitation of phosphates, pH increase, and sorption. The contents of metals before immobilization were determined by extraction in CaCl<sub>2</sub>, EDTA and <italic>aqua regia</italic>. Cadmium and zinc are mainly represented by soluble, bio-available forms extractable in CaCl<sub>2</sub>, while lead by potentially bioavailable speciations extractable by EDTA. Most effective in the immobilization of these metals were the amendments increasing soil pH: limestone powder and phosphate fertilizer. Bog iron ore and bentonite were less effective because the soil pH was too low for efficient cation adsorption.</p> </abstract>ARTICLEtrue teamwork skills in a course on ore deposits<abstract> <title style='display:none'>Abstract</title> <p>Teamwork has distinct pedagogic advantages and is also an important transferable skill and the dominant mode of work graduates encounter in the workplace. However, students rarely become proficient in teamwork skills during their education. The goal was to test strategies to improve teamwork skills in a course on Ores deposits, MSc Earth Science, Uppsala University. A focus on team-work was established by presenting the collaborative practicals as a series of linked opportunities to work together, get feedback on the teamwork process and reflect on and evaluate the teamwork. During the collaborative PBL sessions sociograms were used to provide feedback. Criteria based evaluation was also used to evaluate task oriented and interpersonal skills. Sociograms and criteria based evaluation promoted behavioural changes that improved teamwork interactions.</p> </abstract>ARTICLEtrue minerals and the first mineral occurrences in the Kupferschiefer (U, REE, HgS, chloride minerals PtAs, Pt(Sb,Bi), PtBi), Poland, and their genetic meaning<abstract> <title style='display:none'>Abstract</title> <p>Main U minerals in the Lubin and Polkowice mines in decreasing order of abundance are: uraninite, brannerite, metazunerite, metauranospinite, uranospinite, thucholite, monazite-huttonite, coffinite, and becquerelite. All these minerals are associated mainly with noble metal mineralization at the redox interfaces. Main minerals of REE are: (i) brannerite, monazite-huttonite in Noble Metals Bearing Shale (NMBS), (ii) florencite in Mo-Re shales and (iii) minor phospates in Cu-black shales derived from oxidation of organic matter. The latter, however, are controlling no more than 1/5 of the REE budget. Chloride minerals and sulphates are ubiquitous phases associated with Cu sulphides. They are represented by chlorargylite, cotunnite and penfieldite. Halite and sylvite form cubic inclusions in gypsum, up to 3 mm in chevrel compound, where they occur together with thiosulphates, anna-bergite and erithrite and Ni-Co-diarsenides. Sylvite is most common in lensoidal accumulations of semi massive kaolinite + chalcocite + gypsum at the contact between black shale and the top part of white sandstone. Such lenses have been traced over a distance of up to 30 m in the Lubin West and Polkowice East mines. Sylvite and halite have been so far overlooked during investigations of the Kupferschiefer because of applying standard cuƫng and polishing procedures using water as a lubricant. The Au content in native gold may reach exceptionally up to 97.40 wt% in a dolomitic reef from the Lubin West Mine. Gold forms four characteristic micro to nano-textures. Organic matrix of thucholite indicates correlation of Pt-Ni-V suggesting substitution of Pt in tetrapyrrole ring. Sperrylite, geversite and insizwaite appear at the western perimeter of Cu-sulphide deposit, where the redox gradient is so strong that almost all organic matter is gone. Platinum has forms its own minerals trapped in microfractures in anilite-digenite-spionkopite-yarrowite-bornite composite grains present in the reddened NMBS. Celestine-barite solid solution is one of the main accessory minerals in the Kupferschiefer. It has Sr/Ba ratio around 2.5 and 7.5. Euhedral uraninite associated with celestine-barite yielded U/Pb age of 84 ± 1 Ma, based on four grains measurements.</p> </abstract>ARTICLEtrue studies of the Maastrichtian Gerinya Claystone of the Patti Formation, southern Bida Basin, Nigeria: Implication for industrial application<abstract> <title style='display:none'>Abstract</title> <p>The mineralogical compositions of the Gerinya claystone, Patti Formation, Southern Bida Basin, Nigeria, were investigated to infer their sedimentological process and industrial application. Mineralogical analysis of the claystone was carried out using the X-ray diffraction (XRD) method. The diffractogram peaks aided the identification of the clay and non-clay minerals in the study area. The XRD showed kaolinite as the major clay mineral with compositions ranging from 10.8 - 67.6 wt%. The non-clay minerals were quartz, anatase, diopside, goethite, hematite, rutile, muscovite and micro-cline. Among the non-clay minerals, quartz had the highest percentage mineralogical composition of 21.2 to 83.4 wt%. The mineral assemblage is typical of a hot and humid climate where chemical alteration and hydrolysis of silicate minerals are severe. The sediments are of mafic and felsic crystalline rocks origin. The sediments are of low energy floodplain/interchannel depositional environment. The Gerinya claystone vary from low to high porosity and very low to low permeability. The claystone can be used as clay liners and as raw material for ceramic production. The application of the claystones in fertiliser production will require some processing. The clay-stone can be used for haemorrhage control in the pharmacological/medical sector. Although, the ingestion of the clay-stones could lead to dental damage and possible perforation of the sigmoid colon in the gastrointestinal tract.</p> </abstract>ARTICLEtrue of amorphous Ca-phosphate precipitate caused by bio mineralisation in 4-5 CE lime plasters of the previously submerged east coastal monument of Salvankuppam<abstract> <title style='display:none'>Abstract</title> <p>The lime plasters of the excavated monument of Salvankuppam, previously submerged and exposed by the Tsunami occurred in the Indian Ocean on 26<sup>th</sup> December 2004 was studied with different analytical techniques. The temple is dated 4-5<sup>th</sup> century CE. The XRF, XRD, FTIR, NMR, SEM-EDX analysis of the lime plasters evidenced particular occurrence of phosphatised bacterial remains in saline conditions. The formation of amorphous Ca-phosphate by bio mineralization was identified in the plasters by the analyses. The plasters are made of air-lime with coarse aggregates and seashells inclusion as confirmed by the thermal and chemical analysis. The microstructure and morphological investigations of mineralized microbial structures by SEM-EDX indicated the formation of amorphous Ca-phosphate. The unordered and fibrous spherulites have hardened and reduced porosity of the plaster by bio mineralization as observed through MIP analysis. The 16S rRNA sequencing has identified the Pseudomonas strains mainly responsible for the clustering of amorphous Ca-phosphate particles around the bacterial colony.</p> </abstract>ARTICLEtrue steps for the detection and classification of different lamprophyric rocks: a case study from Greece<abstract> <title style='display:none'>Abstract</title> <p>This study aims to help non-expert geologists in locating, classifying and analyzing lamprophyres, the exotic and complex rocks. The process includes three basic steps, a macroscopic study of the formation, petrographic microscopy and lastly whole-rock and trace element analyses of the samples. Fourteen Greek lamprophyric rocks with distinct characteristics were used. Conventional lamprophyres were considered along with rarer alkali minettes, meta-lamprophyres, lamproschists, appinites and para-lamproites.</p> </abstract>ARTICLEtrue of oil products on the synthetic zeolite granules<abstract> <title style='display:none'>Abstract</title> <p>In this work, lightweight granules of zeolite Na-P1 based on expanded glass aggregates were synthesized for the application in oil products’ sorption. The sorption of gasoline, diesel and silicone oil tests were also conducted for raw expanded glass, zeolite A, clinoptilolite and mineral sorbent available at a fuel station. All sorbents were also characterized in terms of the phase composition (X-ray diffraction) and structure (infrared spectroscopy). The zeolite Na-P1 granules achieved the highest values of sorption capacities (1.8, 2.1 and 2.6 g/g, respectively), which makes them promising materials for oils’ removal.</p> </abstract>ARTICLEtrue of selected mineral and waste sorbents for the capture of elemental mercury from exhaust gases<abstract> <title style='display:none'>Abstract</title> <p>Several mineralogically, chemically and texturally diverse minerals and waste materials were selected for the testing of elemental mercury capture in exhaust gas, namely tyre char resulting from the burning of pyrolytic rubber tyres, class C fly ash, mesoporous material type MCM-41 and glauconite. Each material’s mineralogical, chemical and textural characteristics were explored. In order to conduct experiments in conditions similar to those during the contact of sorbent with real coal exhaust fumes at a temperature of about 110-120°C, the experiments were carried out using a test device consisting of a furnace for burning powdered coals, a thermostatic cage for sorbent reactors and mercury gas analysers, which are able to measure and compare the effects of individual sorbents with exhaust gas. The study found that the best results for mercury sorption in the exhaust atmosphere were obtained for class C ash resulting from brown coal combustion.</p> </abstract>ARTICLEtrue and application of natural sorbents with silver nanoparticles in reducing the emission of odours<abstract> <title style='display:none'>Abstract</title> <p>The paper concerns the applicability of silver nanoparticles for reducing the emission of odours. Silver nanoparticles were successfully adsorbed on three different dolomitic limestone samples. In the next stage, wastewater from the meat industry was mixed with sorbents modified with a variable content of silver nanoparticles. After 4 days and 7 days, the concentration of ammonia was examined spectrophotometrically. Also, the degree of reduction of total odour concentration by olfactometric method was carried out. Depending on the concentration of the silver nanoparticles on the sorbents, the concentration of ammonia was 15-42 μg/cm<sup>3</sup> for nAg content equal to 0.08%, while for sorbents containing approximately 36% of nAg the concentration of ammonia was 0.09-16 μg/cm<sup>3</sup>. A leaching test of nanosilver from sorbents confirmed that the particles were bound with the sorbents by strong bonds. The percentage of eluted silver increased from 0.67% to 11%, with increased initial concentrations of nAg on the sorbents from 0.18% to 0.37%.</p> </abstract>ARTICLEtrue