Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience
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XEDS STEM tomography for 3D chemical characterization of nanoscale particles

XEDS STEM tomography for 3D chemical characterization of nanoscale particles | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The authors present a tomography technique which couples scanning transmission electron microscopy (STEM) and X-ray energy dispersive spectrometry (XEDS) to resolve 3D distribution of elements in nanoscale materials. STEM imaging when combined with XEDS mapping using a symmetrically arranged XEDS detector design around the specimen overcomes many of the obstacles in 3D chemical imaging of nanoscale materials and successfully elucidates the 3D chemical information in a large field of view of the transmission electron microscopy (TEM) sample. They employed this technique to investigate 3D distribution of Nickel (Ni), Manganese (Mn) and Oxygen (O) in a Li1.2Ni0.2Mn0.6O2 (LNMO) nanoparticle used as a cathode material in Lithium (Li) ion batteries.

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Nuclear explosions could tell us why the moon has no water

Scientists are studying debris from the Trinity nuclear test to figure out how the moon lost its water.
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Solving the mysteries of climate

Did you know that a tiny nanoparticle size of less than 0.000000001 meters can help us predict massive global changes? Watch a video of a new researc
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Uranium(IV) adsorption by natural organic matter in anoxic sediments

Uranium(IV) adsorption by natural organic matter in anoxic sediments | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The authors show that adsorption to organic carbon and organic carbon-coated clays dominate U(IV) speciation in an organic-rich natural substrate under field-relevant conditions.
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Mineralogy and Petrology Collection - Museum Department of Earth and Atmospheric Sciences - University of Alberta

Mineralogy and Petrology Collection - Museum Department of Earth and Atmospheric Sciences - University of Alberta | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
#DYK: The Mineralogy & Petrology Collection includes research in the tectonic history of Alberta? https://t.co/4TQajBEpb4 #UAlberta https://t.co/eOPKChEqfm
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Calcite and Hydroxyapatite Gelatin Composites as Bone Substitution Material

Calcite and Hydroxyapatite Gelatin Composites as Bone Substitution Material | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Various composites of calcium containing minerals and organic macromolecules were investigated with respect to bone replacement. Manipulation of the mineralization process was done by new design elements of the double migration technique, influencing crystallization of calcium phosphate and carbonate within a gelatin gel. The minerals morphology and structure were manipulated, influencing the calcium ion release to a desired extent.
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Protein regulation of normal and pathologic mineralization - Biomineralization2014

Protein regulation of normal and pathologic mineralization Par Marc D. McKee De la McGill University
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Uranium-bearing francolites present in organic-rich limestones of NW Greece

Uranium-bearing francolites present in organic-rich limestones of NW Greece | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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Synchrotron radiation techniques (μ-XRF and μ-XANES) were applied to the study of organic-rich phosphatized limestones of NW Greece (Epirus). The results revealed uranium accumulation in areas of the material containing, among others, carbonate apatite (francolite) and organic matter. The UL3-edge of μ-XANES spectra showed that uranium was present in tetravalent form. U-bearing francolite crystals were separated from the rock and characterized by Raman spectroscopy and microprobe. The analysis of the crystals also indicated the presence of sodium and sulfur. The uranium presence in the crystals was also visualized, after neutron irradiation and etching, by the observation of the fission tracks.
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A key role for green rust in the Precambrian oceans and the genesis of iron formations

A key role for green rust in the Precambrian oceans and the genesis of iron formations | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Large iron deposits formed episodically in the Archaean oceans. Experimental data and geochemical modelling suggest that green rust was an important contributor to the formation of these deposits and the Archaean iron cycle in general.
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The authors investigate the potential role of green rust, a ferrous–ferric hydroxy salt, in the genesis of iron formations. Our laboratory experiments show that green rust readily forms in early seawater-analogue solutions, as predicted by thermodynamic calculations, and that it ages into minerals observed in iron formations.
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Early formation of the Moon 4.51 billion years ago

Early formation of the Moon 4.51 billion years ago | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Establishing the age of the Moon is critical to understanding solar system evolution and the formation of rocky planets, including Earth. However, despite its importance, the age of the Moon has never been accurately determined. We present uranium-lead dating of Apollo 14 zircon fragments that yield highly precise, concordant ages, demonstrating that they are robust against postcrystallization isotopic disturbances. Hafnium isotopic analyses of the same fragments show extremely low initial 176Hf/177Hf ratios corrected for cosmic ray exposure that are near the solar system initial value. Our data indicate differentiation of the lunar crust by 4.51 billion years, indicating the formation of the Moon within the first ~60 million years after the birth of the solar system.
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Heterogeneity in mantle carbon content from CO2-undersaturated basalts

Heterogeneity in mantle carbon content from CO2-undersaturated basalts | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The authors used the correlations of CO2 with trace elements to define an average carbon abundance for the upper mantle.
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Formation of carbonate chimneys in the Mediterranean Sea

Formation of carbonate chimneys in the Mediterranean Sea | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The authors have characterized rocks sampled from metre-size build-ups of methane-derived carbonate chimneys located at the Amon mud volcano on the Nile deep-sea fan.
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Environmental controls on biomineralization and Fe-mound formation in a low-temperature hydrothermal system at the Jan Mayen Vent Fields

Environmental controls on biomineralization and Fe-mound formation in a low-temperature hydrothermal system at the Jan Mayen Vent Fields | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The authors conducted 16S rRNA gene analyses, microscopy and geochemical analyses of laminated siliceous Fe-mounds from the Jan Mayen Vent Fields at the Arctic Mid-Ocean Ridge.
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FIRST DETECTION OF BORON ON THE SURFACE OF MARS|FIRST SIGNS OF GROUNDWATER ON MARS

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Dissolution and Sorption Processes on the Surface of Calcite in the Presence of High Co2+ Concentration

Dissolution and Sorption Processes on the Surface of Calcite in the Presence of High Co2+ Concentration | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The interaction of the calcite surface with Co2+-rich aqueous solutions ([Co2+aq]initial = 1000 ppm, i.e., ca. 17 mM) was investigated by means of macroscopic experiments and surface spectroscopic techniques. In the case of the macroscopic experiments, calcite powder and monocrystals were immersed into solutions for different time periods (from 1 min to one month). The Ca concentrations in the filtrates was measured by means of atomic absorption spectrometry (AAS) while the interacted solids were studied using a combination of X-ray photoelectron spectroscopy (XPS) and 12C-rutherford backscattering spectrometry (12C-RBS). The macroscopic data showed a characteristic surface dissolution process, in parallel to the surface sorption processes. Adsorption and co-precipitation were seen for almost the entire immersion period for both calcite powder and monocrystals. The surface study by XPS (analyzed at a depth of approximately 12 nm) suggested that adsorption takes place in the first hour of the interaction, followed by incorporation of Co2+ into calcite surface layers, leading to the formation of a Co2+-bearing surface (co)precipitate, which occurs over a period of hours and days. The 12C-RBS measurements on calcite { 101¯4 } indicated that the thickness of this surface co-precipitate was 270 nm after one day and then stabilized at 320 nm after more than a week.
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The Deep Carbon Observatory

The Deep Carbon Observatory is a global community of multi-disciplinary scientists unlocking the inner secrets of Earth through investigations into life
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Carbon Sequestration in Olivine and Basalt Powder Packed Beds

Carbon Sequestration in Olivine and Basalt Powder Packed Beds | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Magnesite formed in experiments with olivine, and Mg- and Ca-bearing siderite formed in experiments with flood basalt.
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Geologists identify the mineralogy of Mercury

Geologists identify the mineralogy of Mercury | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
For the first time, geologists from the University of Liège have been able to determine the nature of the minerals present on the surface of Mercury - one of the four telluric planets in our solar system. Their study, publishe
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Formation and properties of water from quartz and hydrogen at high pressure and temperature

Formation and properties of water from quartz and hydrogen at high pressure and temperature | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

H2 reacts readily with quartz at low pressure and high temperature producing water.

The structure of the confined water resembles that of highly compressed water.

The pressurized water is a possible trigger for nucleating enigmatic deep earthquakes.

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A distinct source and differentiation history for Kolumbo submarine volcano, Santorini volcanic field, Aegean arc

A distinct source and differentiation history for Kolumbo submarine volcano, Santorini volcanic field, Aegean arc | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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This study reports the first detailed geochemical characterization of Kolumbo submarine volcano in order to investigate the role of source heterogeneity in controlling geochemical variability within the Santorini volcanic field in the central Aegean arc. Kolumbo, situated 15 km to the northeast of Santorini, last erupted in 1650 AD and is thus closely associated with the Santorini volcanic system in space and time. Samples taken by remotely-operated vehicle that were analyzed for major element, trace element and Sr-Nd-Hf-Pb isotope composition include the 1650 AD and underlying K2 rhyolitic, enclave-bearing pumices that are nearly identical in composition (73 wt.% SiO2, 4.2 wt.% K2O). Lava bodies exposed in the crater and enclaves are basalts to andesites (52–60 wt.% SiO2). Biotite and amphibole are common phenocryst phases, in contrast with the typically anhydrous mineral assemblages of Santorini. The strong geochemical signature of amphibole fractionation and the assimilation of lower crustal basement in the petrogenesis of the Kolumbo magmas indicates that Kolumbo and Santorini underwent different crustal differentiation histories and that their crustal magmatic systems are unrelated. Moreover, the Kolumbo samples are derived from a distinct, more enriched mantle source that is characterized by high Nb/Yb (>3) and low 206Pb/204Pb (<18.82) that has not been recognized in the Santorini volcanic products. The strong dissimilarity in both petrogenesis and inferred mantle sources between Kolumbo and Santorini suggests that pronounced source variations can be manifested in arc magmas that are closely associated in space and time within a single volcanic field.
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Nano-mineralogy and -geochemistry of high-grade diasporic karst-type bauxite from Parnassos-Ghiona mines, Greece

Nano-mineralogy and -geochemistry of high-grade diasporic karst-type bauxite from Parnassos-Ghiona mines, Greece | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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In the present work, a combination of various techniques is utilized for the study of nano-mineralogy and -geochemistry of high-grade karst-type bauxite (Al-rich and Fe-depleted samples; Al2O3 ca. 80 wt.%) from the Parnassos-Ghiona mines located in Greece. Initial characterization using PXRD and electron microscopy in microscale and mesoscale (SEM-EDS including STEM mode), proved the presence of “Fe-Cr-Ti-containing diaspore”, anatase and minor rutile. The study by means of 57Fe Mössbauer spectroscopy, in correlation with magnetic susceptibility measurements and, complemented, with Synchrotron-based spectroscopies at the microscale (SR micro-XRF and micro-XANES/-EXAFS), indicated that Fe3+, in contrast to [6]Cr3+, is not exclusively a component of the diaspore structure. While Cr3 + substitutes Al3 + in octahedral sites of diaspore ([6]Cr3+ ↔ [6]Al3+), the electron microscopy in nanoscale (TEM-EDS & EELS) revealed that Fe exists in the form of peculiar Fe3+-bearing nanominerals (most likely maghemite-type phases) between 25 and 45 nm in size, in addition to the Fe3+ ions substituting Al3+ in the diaspore structure. Moreover, it was proven that TiO2 polymorph mineral nanoparticles, particularly rounded anatase mesocrystals and nanocrystals and individual needle-shaped rutiles, are dispersed into the diaspore matrix. Thus, diaspore in the studied bauxite concerns -in fact- a distinct Fe3+-Cr3+-AlOOH low-T authigenic phase, demonstrated for the first time in literature. On the other hand, the observed TiO2 mineral nanoparticles (formed, together with diaspore, during diagenesis) and Fe nanominerals (formed during epigenesis) were hitherto unknown not only for the allochthonous karst-type bauxite deposits of Greece, but also for the overall bauxite deposits, worldwide.
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Green synthesis of pyrite nanoparticles for energy conversion and storage: a spectroscopic investigation

Green synthesis of pyrite nanoparticles for energy conversion and storage: a spectroscopic investigation | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Pyrite, FeS2, nanoparticles were obtained through a one-pot solvothermal synthesis, without surfactants, carried out at room pressure and mild temperature (~180°C).
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Hydrogenation of iron in the early stage of Earth’s evolution

Hydrogenation of iron in the early stage of Earth’s evolution | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
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The authors carried out high-pressure and high-temperature in situ neutron diffraction experiments and clarify that when the mixture of iron and hydrous minerals are heated, iron is hydrogenized soon after the hydrous mineral is dehydrated.
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Formation of amorphous calcium carbonate in caves and its implications for speleothem research

Formation of amorphous calcium carbonate in caves and its implications for speleothem research | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
An innovative sampling and measurement protocol combined with scanning and transmission electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy is presented, demonstrating that carbonate precipitating from drip water in caves at ~10 °C contains amorphous calcium carbonate (ACC) that later transforms to nanocrystalline calcite.
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Selection and Use of Manganese Dioxide by Neanderthals

Selection and Use of Manganese Dioxide by Neanderthals | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Several Mousterian sites in France have yielded large numbers of small black blocs.
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Compositional analyses lead the authors to infer that late Neanderthals at Pech-de-l’Azé I were deliberately selecting manganese dioxide.
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Silicate mineralogy at the surface of Mercury

Silicate mineralogy at the surface of Mercury | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Near-infrared to ultraviolet spectra and images have provided evidence for the Fe2+-poor nature of silicate minerals, magnesium sulfide minerals in hollows and a darkening component attributed to graphite, but existing spectral data is insufficient to build a mineralogical map for the planet.
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