Article
Licensed
Unlicensed
Requires Authentication
Si-magnetite nano-precipitates in silician magnetite from banded iron formation: Z-contrast imaging and ab initio study
-
Huifang Xu
,
Zhizhang Shen
Published/Copyright:
November 12, 2014
Abstract
Si-bearing magnetite or silician magnetite is common in low- and high-temperature rocks. However, details about possible Fe-silicate or Si-Fe-oxide discrete phases/nano-precipitates were not available due to the limitations of conventional high-resolution TEM. Combining Z-contrast imaging and ab initio calculation using density functional theory (DFT) method, we have derived both composition and crystals structure of the discrete nano-precipitates within host magnetite. The nano-precipitates of Si-magnetite with composition of [¨0.5Fe2+ 0.5]VI[Fe3+]VISiIVO4 or g-Fe1.5SiO4 occur in silician magnetite from a banded iron formation from Western Australia. In the Si-magnetite precipitates, Si replaces Fe3+ in tetrahedral sites of the magnetite structure and vacancies are introduced in the octahedral Fe2+ sites. The Si-magnetite precipitates distribute along {111} of the host magnetite. Widths of the precipitates are even multiples of d111 of magnetite, such as 2d111, 4d111, and 6d111. Ordering of the vacancies in the Si-magnetite will result in symmetry of P4332, which is a subgroup of Fd3m for magnetite. Stacking of Si-magnetite and magnetite (111) layers along the [111] direction also occur in magnetite. The nanoprecipitates result from exsolution of Si-magnetite from the host silician magnetite at low temperature. The occurrence of the thin nano-precipitates within the magnetite host results from the minimization of interfacial energy between the precipitate and the host magnetite. Relatively high concentrations of aqueous silica and Fe-silicate complex species in pore fluid might enhance the incorporation of Si into the silician magnetite during crystallization of the magnetite.
Received: 2014-3-7
Accepted: 2014-6-4
Published Online: 2014-11-12
Published in Print: 2014-11-1
© 2014 by Walter de Gruyter Berlin/Boston
You are currently not able to access this content.
You are currently not able to access this content.
Articles in the same Issue
- Highlights and Breakthroughs Merrillite and apatite as recorders of planetary magmatic processes
- Highlights and Breakthroughs Comparing clays from Mars and Earth: Implications for martian habitability
- Data-driven abductive discovery in mineralogy
- Thermal expansion of fluorapatite-hydroxylapatite crystalline solutions
- Synthesis and structure of carbonated barium and lead fluorapatites: Effect of cation size on A-type carbonate substitution
- Optical absorption spectroscopy study of the causes for color variations in natural Fe-bearing gahnite: Insights from iron valency and site distribution data
- Si-magnetite nano-precipitates in silician magnetite from banded iron formation: Z-contrast imaging and ab initio study
- Ordering kinetics in synthetic Mg(Al,Fe3+)2O4 spinels: Quantitative elucidation of the whole Al-Mg-Fe partitioning, rate constants, activation energies
- Experimental study of phlogopite reaction rim formation on olivine in phonolite melts: Kinetics, reaction rates, and residence times
- Etch-pit size, dissolution rate, and time in the experimental dissolution of olivine: Implications for estimating olivine lifetime at the surface of Mars
- Ferrian saponite from the Santa Monica Mountains (California, U.S.A., Earth): Characterization as an analog for clay minerals on Mars with application to Yellowknife Bay in Gale Crater
- A large spectral survey of small lunar craters: Implications for the composition of the lunar mantle
- In-situ characterization of oxalic acid breakdown at elevated P and T: Implications for organic C-O-H fluid sources in petrologic experiments
- Slawsonite-celsian-hyalophane assemblage from a picrite sill (Prague Basin, Czech Republic)
- Determining hematite content from NUV/Vis/NIR spectra: Limits of detection
- The role of water in generation of group II kimberlite magmas: Constraints from multiple saturation experiments
- Quantum mechanical modeling of hydrolysis and H2O-exchange in Mg-, Ca-, and Nisilicate clusters: Implications for dissolution mechanisms of olivine minerals
- Redox-driven exsolution of iron-titanium oxides in magnetite in Miller Range (MIL) 03346 nakhlite: Evidence for post crystallization oxidation in the nakhlite cumulate pile?
- Energetics of lanthanide-doped calcium phosphate apatite
- Thermal conductivity of molten and glassy NaAlSi3O8, CaMgSi2O6, and Mg2SiO4 by non-equilibrium molecular dynamics at elevated temperature and pressure
- Energetics of heterometal substitution in ε-Keggin [MO4Al12(OH)24(OH2)12]6/7/8+ ions
- Ab initio calculations of elastic constants of plagioclase feldspars
- Diagenetic formation of interlayer-deficient fluorophlogopite as a clay mineral in Early Cambrian phosphorite (Lesser Himalaya, India): The trioctahedral analog of illite
- Natural sepiolite: Enthalpies of dehydration, dehydroxylation, and formation derived from thermochemical studies
- A new interpretation of decomposition products of serpentine under shock compression
- model for calculating the viscosity of natural iron-bearing silicate melts over a wide range of temperatures, pressures, oxygen fugacites, and compositions
- The replacement of chalcopyrite by bornite under hydrothermal conditions
- Characterization of porosity in sulfide ore minerals: A USANS/SANS study
- Synthesis of a quenchable high-pressure form of magnetite (h-Fe3O4) with composition Fel(Fe2+0.75Mg0.26)Fe2(Fe3+ 0.70Cr0.15Al0.11Si0.04)2O4
- High-pressure elasticity of sodium majorite garnet, Na2MgSi5O12
- Armstrongite from Khan Bogdo (Mongolia): Crystal structure determination and implications for zeolite-like cation exchange properties
- Steinhardtite, a new body-centered-cubic allotropic form of aluminum from the Khatyrka CV3 carbonaceous chondrite
- New Mineral Names
- Book Review
Keywords for this article
Si-magnetite;
silician magnetite;
banded iron formation;
Z-contrast imaging;
DFT
Articles in the same Issue
- Highlights and Breakthroughs Merrillite and apatite as recorders of planetary magmatic processes
- Highlights and Breakthroughs Comparing clays from Mars and Earth: Implications for martian habitability
- Data-driven abductive discovery in mineralogy
- Thermal expansion of fluorapatite-hydroxylapatite crystalline solutions
- Synthesis and structure of carbonated barium and lead fluorapatites: Effect of cation size on A-type carbonate substitution
- Optical absorption spectroscopy study of the causes for color variations in natural Fe-bearing gahnite: Insights from iron valency and site distribution data
- Si-magnetite nano-precipitates in silician magnetite from banded iron formation: Z-contrast imaging and ab initio study
- Ordering kinetics in synthetic Mg(Al,Fe3+)2O4 spinels: Quantitative elucidation of the whole Al-Mg-Fe partitioning, rate constants, activation energies
- Experimental study of phlogopite reaction rim formation on olivine in phonolite melts: Kinetics, reaction rates, and residence times
- Etch-pit size, dissolution rate, and time in the experimental dissolution of olivine: Implications for estimating olivine lifetime at the surface of Mars
- Ferrian saponite from the Santa Monica Mountains (California, U.S.A., Earth): Characterization as an analog for clay minerals on Mars with application to Yellowknife Bay in Gale Crater
- A large spectral survey of small lunar craters: Implications for the composition of the lunar mantle
- In-situ characterization of oxalic acid breakdown at elevated P and T: Implications for organic C-O-H fluid sources in petrologic experiments
- Slawsonite-celsian-hyalophane assemblage from a picrite sill (Prague Basin, Czech Republic)
- Determining hematite content from NUV/Vis/NIR spectra: Limits of detection
- The role of water in generation of group II kimberlite magmas: Constraints from multiple saturation experiments
- Quantum mechanical modeling of hydrolysis and H2O-exchange in Mg-, Ca-, and Nisilicate clusters: Implications for dissolution mechanisms of olivine minerals
- Redox-driven exsolution of iron-titanium oxides in magnetite in Miller Range (MIL) 03346 nakhlite: Evidence for post crystallization oxidation in the nakhlite cumulate pile?
- Energetics of lanthanide-doped calcium phosphate apatite
- Thermal conductivity of molten and glassy NaAlSi3O8, CaMgSi2O6, and Mg2SiO4 by non-equilibrium molecular dynamics at elevated temperature and pressure
- Energetics of heterometal substitution in ε-Keggin [MO4Al12(OH)24(OH2)12]6/7/8+ ions
- Ab initio calculations of elastic constants of plagioclase feldspars
- Diagenetic formation of interlayer-deficient fluorophlogopite as a clay mineral in Early Cambrian phosphorite (Lesser Himalaya, India): The trioctahedral analog of illite
- Natural sepiolite: Enthalpies of dehydration, dehydroxylation, and formation derived from thermochemical studies
- A new interpretation of decomposition products of serpentine under shock compression
- model for calculating the viscosity of natural iron-bearing silicate melts over a wide range of temperatures, pressures, oxygen fugacites, and compositions
- The replacement of chalcopyrite by bornite under hydrothermal conditions
- Characterization of porosity in sulfide ore minerals: A USANS/SANS study
- Synthesis of a quenchable high-pressure form of magnetite (h-Fe3O4) with composition Fel(Fe2+0.75Mg0.26)Fe2(Fe3+ 0.70Cr0.15Al0.11Si0.04)2O4
- High-pressure elasticity of sodium majorite garnet, Na2MgSi5O12
- Armstrongite from Khan Bogdo (Mongolia): Crystal structure determination and implications for zeolite-like cation exchange properties
- Steinhardtite, a new body-centered-cubic allotropic form of aluminum from the Khatyrka CV3 carbonaceous chondrite
- New Mineral Names
- Book Review
