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3D NanoChemiscope

So entsteht an der Empa ein neues Hightech-Analysegerät: Das 3D-NanoChemiscope kann die Feinstruktur einer Oberfläche „sehen" und analysiert die chemische Zu...
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Redox cycling of Fe(II) and Fe(III) in magnetite by Fe-metabolizing bacteria

Ath Godelitsas's insight:

The authors show through magnetic and spectroscopic measurements that the phototrophic Fe(II)-oxidizing bacterium Rhodopseudomonas palustris TIE-1 oxidizes magnetite (Fe3O4) nanoparticles using light energy.

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Experimental diagenesis of organo-mineral structures formed by microaerophilic Fe(II)-oxidizing bacteria

Experimental diagenesis of organo-mineral structures formed by microaerophilic Fe(II)-oxidizing bacteria | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Twisted stalks are organo-mineral structures produced by some microaerophilic Fe(II)-oxidizing bacteria at O2 concentrations as low as 3 μM.

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Can clays ensure nuclear waste repositories?

Can clays ensure nuclear waste repositories? | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The authors have analyzed -at nanoscale level- the calcite/clay assembly, the main constituents of argillite, under storage conditions and show the fragility of the montmorillonite with respect to calcite.

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Porphyry copper deposit formation by sub-volcanic sulphur dioxide flux and chemisorption

Porphyry copper deposit formation by sub-volcanic sulphur dioxide flux and chemisorption | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

The processes that create economic-grade accumulations of metals above magma chambers are unclear. High-temperature laboratory experiments show that rapid reactions between magmatic gases and Earth's crust can trigger efficient metal deposition.

Ath Godelitsas's insight:

The authors use high-temperature laboratory experiments to show that a very rapid chemisorption reaction occurs between sulphur dioxide gas, a principal component of magmatic gas mixtures, and calcic feldspar, an abundant mineral in the arc crust. The chemisorption reaction generates the mineral anhydrite and hydrogen sulphide gas, and triggers deposition of metal sulphides.

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Birnessite (δ-MnO2) Mediated Degradation of Organoarsenic Feed Additive p-Arsanilic Acid

Birnessite (δ-MnO2) Mediated Degradation of Organoarsenic Feed Additive p-Arsanilic Acid | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

A common soil metal oxide, birnessite (δ-MnO2), was found to mediate its degradation with fast rates under acidic conditions. Experimental results indicate that adsorption and degradation of p-ASA on the surface of δ-MnO2 were highly pH dependent, and the overall kinetics for p-ASA degradation and formation of precursor complex could be described by a retarded first-order rate model.

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Agromining: Farming for Metals in the Future?

Agromining: Farming for Metals in the Future? | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Phytomining technology employs hyperaccumulator plants to take up metal in harvestable plant biomass. Harvesting, drying and incineration of the biomass generates a high-grade bio-ore. We propose that “agromining” (a variant of phytomining) could provide local communities with an alternative type of agriculture on degraded lands; farming not for food crops, but for metals such as nickel (Ni).

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Flash glass: Lightning inside volcanic ash plumes create glassy spherules

Flash glass: Lightning inside volcanic ash plumes create glassy spherules | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Surface tension shapes lightning-melted ash into balls
Ath Godelitsas's insight:

A team sifting through ash samples collected downwind after eruptions at Alaska’s Mount Redoubt in 2009 and Iceland’s Eyjafjallajökull in 2010 found such spherules, the first attributed to volcanic eruptions. (Similar spherules can be formed in a variety of extreme circumstances, from bomb explosions to extraterrestrial impacts). See also: http://geology.gsapubs.org/content/early/2015/02/26/G36255.1

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The “Picasso of low-temperature geochemistry” has died: Robert Berner, 1935-2015

The “Picasso of low-temperature geochemistry” has died: Robert Berner, 1935-2015 | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
The “Picasso of low-temperature geochemistry” has died
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Effect of Fulvic Acid Surface Coatings on Plutonium Sorption and Desorption Kinetics on Goethite

Effect of Fulvic Acid Surface Coatings on Plutonium Sorption and Desorption Kinetics on Goethite | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The authors investigated the effects of FA on Pu(IV) sorption/desorption onto goethite in two scenarios: when FA was (1) initially present in solution or (2) found as organic coatings on the mineral surface. A low pH was used to maximize FA coatings on goethite.

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Spectroscopic Evidence of Uranium Immobilization in Acidic Wetlands

Spectroscopic Evidence of Uranium Immobilization in Acidic Wetlands | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The objective of this work was to study molecular mechanisms responsible for high U retention by Savannah River Site (SRS) wetland sediments under varying redox and acidic (pH = 2.6–5.8) conditions using U L3-edge X-ray absorption spectroscopy.

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Metal Stable Isotope Signatures as Tracers in Environmental Geochemistry

Metal Stable Isotope Signatures as Tracers in Environmental Geochemistry | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
The biogeochemical cycling of metals in natural systems is often accompanied by stable isotope fractionation which can now be measured due to recent analytical advances. In consequence, a new research field has emerged over the last two decades, complementing the traditional stable isotope systems (H, C, O, N, S) with many more elements across the periodic table (Li, B, Mg, Si, Cl, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Ge, Se, Br, Sr, Mo, Ag, Cd, Sn, Sb, Te, Ba, W, Pt, Hg, Tl, U) which are being explored and potentially applicable as novel geochemical tracers.
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Muonium in Stishovite: Possible Existence of Neutral Atomic Hydrogen in the Earth's Deep Mantle

Muonium in Stishovite: Possible Existence of Neutral Atomic Hydrogen in the Earth's Deep Mantle | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The authors present Muon Spin Rotation experiments on SiO2 stishovite, which is an archetypal high-pressure mineral. Positive muon (which can be considered as a light isotope of proton) implanted in stishovite was found to capture electron to form muonium (corresponding to neutral hydrogen).

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X-ray machine opens new frontier

X-ray machine opens new frontier | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Researchers in Palo Alto in the US state of California are working with the most powerful X-ray laser in the world.
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Slab stagnation in the shallow lower mantle linked to an increase in mantle viscosity

Slab stagnation in the shallow lower mantle linked to an increase in mantle viscosity | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The main phases of the lower mantle, bridgmanite and ferropericlase, do not show any structural transitions at these depths, so only moderate and smooth viscosity variations are expected with depthto at least ~2,500 km. The reason for slab stagnation, which may also lead to the formation of chemically distinct reservoirs in Earth’s deep mantle, is therefore unclear. The authors have used synchrotron radial X-ray diffraction to measure in situ the deformation behaviour of ferropericlase at pressures of up to 96 GPa.

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Tetrahedrally coordinated carbonates in Earth’s lower mantle

Tetrahedrally coordinated carbonates in Earth’s lower mantle | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Above 80 GPa, in situ synchrotron infrared experiments show the unequivocal spectroscopic signature of the high-pressure phase of (Mg,Fe)CO3. Using ab-initio calculations, the authors assign the new infrared signature to C–O bands associated with tetrahedrally coordinated carbon with asymmetric C–O bonds. Tetrahedrally coordinated carbonates are expected to exhibit substantially different reactivity than low-pressure threefold coordinated carbonates, as well as different chemical properties in the liquid state.

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Goldschmidt 2015 - YouTube

Goldschmidt2015 will be the 25th Goldschmidt conference, and to celebrate it we are returning to beautiful Prague, the same venue as Goldschmidt2011.
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Pb pollution from leaded gasoline in South America in the context of a 2000-year metallurgical history

Pb pollution from leaded gasoline in South America in the context of a 2000-year metallurgical history | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The authors show that anthropogenic Pb pollution levels from road traffic in South America exceed those of any historical metallurgy in the last two millennia, even in regions with exceptional high local metallurgical activity.

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Mechanisms of Sb(III) Oxidation by Pyrite-Induced Hydroxyl Radicals and Hydrogen Peroxide

Mechanisms of Sb(III) Oxidation by Pyrite-Induced Hydroxyl Radicals and Hydrogen Peroxide | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Sb(III) can be oxidized to Sb(V) in the presence of pyrite, which will greatly influence the fate of Sb(III) in the environment.

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How does your crystal grow? A commentary on Burton, Cabrera and Frank (1951)

How does your crystal grow? A commentary on Burton, Cabrera and Frank (1951) | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society.

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Distribution and partitioning of major and trace elements in pyrite-bearing sediments of a Mediterranean coastal lagoon

Distribution and partitioning of major and trace elements in pyrite-bearing sediments of a Mediterranean coastal lagoon | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The formation of iron sulphide minerals exerts significant control on the behaviour of trace elements in sediments. In this study, three short sediment cores, retrieved from the remote Antinioti lagoon (N. Kerkyra Island, NW Greece), are investigated concerning the solid phase composition, distribution, and partitioning of major (Al, Fe) and trace elements (Cd, Cu, Mn, Pb, and Zn).

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NASA | Satellite Tracks Saharan Dust to Amazon in 3-D

For more information: http://www.nasa.gov/content/goddard/nasa-satellite-reveals-how-much-saharan-dust-feeds-amazon-s-plants For the first time, a NASA satel...
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Atom Exchange between Aqueous Fe(II) and Structural Fe in Clay Minerals

Atom Exchange between Aqueous Fe(II) and Structural Fe in Clay Minerals | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The authors used an enriched isotope tracer approach to simultaneously trace Fe atom movement from the aqueous phase to the solid (57Fe) and from the solid into the aqueous phase (56Fe).

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Aggregation, Dissolution, and Transformation of Copper Nanoparticles in Natural Waters

Aggregation, Dissolution, and Transformation of Copper Nanoparticles in Natural Waters | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Nano-Cu and Cu(OH)2 aggregated rapidly to >103 nm while the aggregate size of nano-CuO averaged between 250 and 400 nm. Aggregate size for both nano-Cu and nano-CuO showed a positive correlation with ionic strength with a few exceptions. Aggregate size did not correlate well with sedimentation rate, suggesting sedimentation was influenced by other factors.

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Coupled Redox Transformation of Chromate and Arsenite on Ferrihydrite

Coupled Redox Transformation of Chromate and Arsenite on Ferrihydrite | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray absorption spectroscopy (XAS), and X-ray photoelectron spectroscopy (XPS) were used to determine the composition of the adsorbed layer on Fh during and after exposure to solution-phase Cr(VI) and As(III).

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Earth's Phosphides in Levant and insights into the source of Archean prebiotic phosphorus

Earth's Phosphides in Levant and insights into the source of Archean prebiotic phosphorus | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Seven minerals from the ternary Fe-Ni-P system have been identified with five of them, NiP2, Ni5P4, Ni2P, FeP and FeP2, previously unknown in nature.

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