Characterization of cation environments in polycrystalline forsterite by 25Mg MAS, MQMAS, and QCPMG NMR
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Michael C. Davis
Abstract
Forsterite (Mg2SiO4) is a silicate mineral frequently studied in the Earth sciences as it has a simple crystal structure and fast dissolution kinetics (elemental release rates under typical conditions on the order of 10-7 mol/m2/s1). During the dissolution process, spectroscopic techniques are often utilized to augment solution chemical analysis and to provide data for determining reaction mechanisms. Nuclear magnetic resonance (NMR) is able to interrogate the local bonding arrangement and coordination of a particular nuclide to obtain structural information. Although previous NMR studies have focused on the silicon and oxygen environments in forsterite, studies focusing on the two nonequivalent magnesium environments in forsterite are limited to a few single-crystal studies. In this study, we present the results of 25Mg MAS, MQMAS, and static QCPMG experiments performed on a powdered sample of a pure synthetic forsterite. We also present spectral fits obtained from simulation software packages, which directly provide quadrupolar parameters for 25Mg nuclei occupying each of the two nonequivalent magnesium sites in the forsterite structure. These results are compared to calculations of the electric field gradient tensor conducted in previous ab initio studies to make definitive assignments correlating each peak to their respective magnesium site in the forsterite structure. Althought previous NMR investigations of forsterite have focused on single-crystal samples, we have focused on powdered forsterite as the increased surface area of powdered samples makes them more amenable to laboratory-scale dissolution studies and, ultimately, the products from chemical weathering may be monitored and quantified.
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Characterization of cation environments in polycrystalline forsterite by 25Mg MAS, MQMAS, and QCPMG NMR
- Structure of nanocrystalline phyllomanganates produced by freshwater fungi
- First-principles study on variation of lattice parameters of mullite Al4+2xSi2–2xO10–x (x = 0.125, 0.250, 0.375)
- Natrolite may not be a “soda-stone” anymore: Structural study of fully K-, Rb-, and Cs-exchanged natrolite
- Metal retention, mineralogy, and design considerations of a mature permeable reactive barrier (PRB) for acidic mine water drainage in Northumberland, U.K.
- A relationship between d104 value and composition in the calcite-disordered dolomite solid-solution series
- XRD, micro-XANES, EMPA, and SIMS investigation on phlogopite single crystals from Mt. Vulture (Italy)
- Volume behavior of the 10 Å phase at high pressures and temperatures, with implications for H2O content
- Interfacial tension between immiscible liquids in the system K2O-FeO-Fe2O3-Al2O3-SiO2 and implications for the kinetics of silicate melt unmixing
- H2O and the dehydroxylation of phyllosilicates: An infrared spectroscopic study
- Effects of intermediate range structure on the 29Si NMR chemical shifts of framework silicates: Results for analcime
- High-temperature Mössbauer spectroscopy: A probe for the relaxation time of Fe species in silicate melts and glasses
- The thermal equation of state of FeTiO3 ilmenite based on in situ X-ray diffraction at high pressures and temperatures
- OH species, U ions, and CO/CO2 in thermally annealed metamict zircon (ZrSiO4)
- Crystallographic and chemical constraints on the nature of the proustite–pyrargyrite solid-solution series
- Accurate μRaman characterization of reaction products at the surface of (bio)oxidized pyrite
- Determination of manganese valence states in (Mn3+, Mn4+) minerals by electron energy-loss spectroscopy
- AFM study of the epitaxial growth of brushite (CaHPO4·2H2O) on gypsum cleavage surfaces
- Compressibility of protoamphibole: A high-pressure single-crystal diffraction study of protomangano-ferro-anthophyllite
- Crystal structure of hydrous wadsleyite with 2.8% H2O and compressibility to 60 GPa
- Dehydration and rehydration processes in gmelinite: An in situ X-ray single-crystal study
- Characteristics of emission centers in alkali feldspar: A new approach by using cathodoluminescence spectral deconvolution
- Mechanism of metamorphic zircon growth in a granulite-facies quartzite, Adirondack Highlands, Grenville Province, New York
- Speciation and mixing behavior of silica-saturated aqueous fluid at high temperature and pressure
- A critical comment on Thy et al. (2009b): Liquidus temperatures of the Skaergaard magma
Articles in the same Issue
- Characterization of cation environments in polycrystalline forsterite by 25Mg MAS, MQMAS, and QCPMG NMR
- Structure of nanocrystalline phyllomanganates produced by freshwater fungi
- First-principles study on variation of lattice parameters of mullite Al4+2xSi2–2xO10–x (x = 0.125, 0.250, 0.375)
- Natrolite may not be a “soda-stone” anymore: Structural study of fully K-, Rb-, and Cs-exchanged natrolite
- Metal retention, mineralogy, and design considerations of a mature permeable reactive barrier (PRB) for acidic mine water drainage in Northumberland, U.K.
- A relationship between d104 value and composition in the calcite-disordered dolomite solid-solution series
- XRD, micro-XANES, EMPA, and SIMS investigation on phlogopite single crystals from Mt. Vulture (Italy)
- Volume behavior of the 10 Å phase at high pressures and temperatures, with implications for H2O content
- Interfacial tension between immiscible liquids in the system K2O-FeO-Fe2O3-Al2O3-SiO2 and implications for the kinetics of silicate melt unmixing
- H2O and the dehydroxylation of phyllosilicates: An infrared spectroscopic study
- Effects of intermediate range structure on the 29Si NMR chemical shifts of framework silicates: Results for analcime
- High-temperature Mössbauer spectroscopy: A probe for the relaxation time of Fe species in silicate melts and glasses
- The thermal equation of state of FeTiO3 ilmenite based on in situ X-ray diffraction at high pressures and temperatures
- OH species, U ions, and CO/CO2 in thermally annealed metamict zircon (ZrSiO4)
- Crystallographic and chemical constraints on the nature of the proustite–pyrargyrite solid-solution series
- Accurate μRaman characterization of reaction products at the surface of (bio)oxidized pyrite
- Determination of manganese valence states in (Mn3+, Mn4+) minerals by electron energy-loss spectroscopy
- AFM study of the epitaxial growth of brushite (CaHPO4·2H2O) on gypsum cleavage surfaces
- Compressibility of protoamphibole: A high-pressure single-crystal diffraction study of protomangano-ferro-anthophyllite
- Crystal structure of hydrous wadsleyite with 2.8% H2O and compressibility to 60 GPa
- Dehydration and rehydration processes in gmelinite: An in situ X-ray single-crystal study
- Characteristics of emission centers in alkali feldspar: A new approach by using cathodoluminescence spectral deconvolution
- Mechanism of metamorphic zircon growth in a granulite-facies quartzite, Adirondack Highlands, Grenville Province, New York
- Speciation and mixing behavior of silica-saturated aqueous fluid at high temperature and pressure
- A critical comment on Thy et al. (2009b): Liquidus temperatures of the Skaergaard magma
