... ultramafic assemblages, in order of increasing grade: serpentine-forsterite-diopside, serpentine-forsterite-tremolite, forsterite-talc, forsterite-anthophyllite, forsterite-enstatite-anthophyllite, forsterite-enstatite-chlorite, forsterite-enstatite-spinel. Associated metarodingites display five metamorphic zones, ... anthophyllite-out isograd, but within the field of forsterite+tremolite, these chlorite-rich rocks react to form the assemblage: forsterite-enstatite-spinel. Calculations show that cordierite did not ...
Tópico(s): Geochemistry and Elemental Analysis
1975 - Oxford University Press | Journal of Petrology
... ultramafic assemblages, in order of increasing grade: serpentine-forsterite-diopside, serpentine-forsterite-tremolite, forsterite-talc, forsterite-anthophyllite, forsterite-enstatite-anthophyllite, forsterite-enstatite-chlorite, forsterite-enstatite-spinel. Associated metarodingites display five metamorphic zones, ... anthophyllite-out isograd, but within the field of forsterite+tremolite, these chlorite-rich rocks react to form the assemblage: forsterite-enstatite-spinel. Calculations show that cordierite did not ...
Tópico(s): Geochemistry and Elemental Analysis
1975 - Oxford University Press | Journal of Petrology
... and nature of the coexisting phases such as forsterite, silica, other pyroxene, and liquid. Broadly, protopyroxene contains ... pigeonite as temperature drops, at 1276°C when forsterite, diopside and liquid coexist, but at other temperatures ... other phases coexist. The assemblage orthopyroxene, anorthite, diopside, forsterite is established as the solidus at 1244°C ... analyses, and not protopyroxene with anorthite, diopside, and forsterite as was previously accepted. Liquidus surfaces for forsterite and protopyroxene, forsterite and orthopyroxene, and forsterite and ...
Tópico(s): Concrete and Cement Materials Research
1985 - Cambridge University Press | Mineralogical Magazine
Stephan Weinbruch, H. Palme, Wolfgang Friedrich Müller, A. El Goresy,
... a gas and not by thermal equilibration of forsterite with FeO‐rich metal or FeO‐rich olivine ... similar origin is inferred for fayalitic veins within forsterite crystals. A good correlation of FeO with MnO ... rich olivine, were found at the boundary between forsterite and fayalite‐rich rim, within the rim itself ... source of Cr is available. Chromite at the forsterite‐fayalite interface was formed by diffusion of Cr from forsterite. Increasingly oxidizing conditions, apparently enabled formation of chromite. ...
Tópico(s): Geological and Geochemical Analysis
1990 - Wiley | Meteoritics
... and Alais, is dominated by minute (< 30 μm) forsterite. Twenty three forsterite grains of these meteorites as well as large forsterites in two chondritic porous interplanetary dust particles (IDPs) ... generally, but not always, higher than found in forsterites of C2, C3 and unequilibrated ordinary chondrites (UOC). Forsterite in Orgueil contains 900 to 6200 ppmw MnO while Alais forsterite has less than 2000 ppmw MnO suggesting that the forsterites in the two meteorites are chemically distinct. Alais ...
Tópico(s): Isotope Analysis in Ecology
1990 - Wiley | Meteoritics
Mahshid Kharaziha, Mohammadhossein Fathi,
Forsterite ceramic is a new bioceramic with good biocompatibility. However, the degradation rate of forsterite ceramic is extremely low, and the apatite-formation ... work was preparation, characterization and bioactivity evaluation of forsterite nanopowder. Forsterite nanopowder was synthesized by the sol–gel process. Bioactivity evaluation was preformed by immersing the forsterite powder in the simulated body fluid (SBF) and apatite formation on the surface of the immersed forsterite nanopowders was investigated. Results showed the particle size ...
Tópico(s): Dental Implant Techniques and Outcomes
2009 - Elsevier BV | Ceramics International
Steven D. Jacobsen, Fuming Jiang, Zhu Mao, T. S. Duffy, Joseph R. Smyth, C. M. Holl, D. J. Frost,
... 1999]. The OH-chondrodite co-existed with hydrous forsterite in the synthesis run, and all other samples ... the study have been confirmed to be hydrous forsterite. Upon removing the OH-chondrodite platelet from the ... of Fe (%)dd Percent change compared with anhydrous forsterite. Hy-Fo100ee This study. Effect of H2O (%)dd Percent change compared with anhydrous forsterite. Hy-Fo97ee This study. Effect of Fe and H2O (%)dd Percent change compared with anhydrous forsterite. Mg# 1.00 0.90 1.00 0. ... Webb [1989]. d Percent change compared with anhydrous forsterite. e This study. f Water contents estimated using ...
Tópico(s): CO2 Sequestration and Geologic Interactions
2009 - American Geophysical Union | Geophysical Research Letters
Aki Takigawa, Shogo Tachibana, H. Nagahara, Kazuhito Ozawa, M. Yokoyama,
... The peak positions of infrared (IR) spectra of forsterite, which is the most abundant circumstellar silicate, vary ... shape." We focused on anisotropic evaporation of crystalline forsterite as one of the possible processes that change the crystallographically anisotropic shape of forsterite grains, and carried out evaporation experiments of single crystals of forsterite in hydrogen gas (0.01–10 Pa) and at temperatures of 1150–1660°C. Forsterite evaporated anisotropically in all experimental conditions, and the ...
Tópico(s): Molecular Spectroscopy and Structure
2009 - IOP Publishing | The Astrophysical Journal
Emad Mustafa, N.M. Khalil, A.A. EL GAMAL,
Spinel–forsterite phase mixtures formed by the addition of different proportions of alumina to forsterite grog's mixes, containing 10–15% alumina, showed ... microstructure after firing at 1450 and 1500 °C. Forsterite was first prepared from Egyptian talc and calcined magnesite at 1400 °C/2 h. Forsterite shows good density but the microstructure contains cracks ... of alumina. Alumina reacts with equimolar MgO from forsterite to form MgAl2O4 spinel on sintering at 1450 °C/2 h. Forsterite occurs in either patches or euhedral rhombic grains. ...
Tópico(s): Nuclear materials and radiation effects
2002 - Elsevier BV | Ceramics International
Shogo Tachibana, A. Tsuchiyama, H. Nagahara,
... primitive solar nebula. Enstatite (MgSiO3) evaporates incongruently forming forsterite (Mg2SiO4) as an evaporation residue; therefore, evaporation of ... temperatures of 1300 to 1500°C. A polycrystalline forsterite layer is formed on the surface of enstatite ... and in hydrogen gas. The thickness of the forsterite layer in vacuum increases with time in the ... of evaporation and later the thickness of the forsterite layer remains constant (several microns). This is due ... nucleation and growth to diffusion in the surface forsterite layer. The activation energy of the diffusion-controlled ...
Tópico(s): Spacecraft and Cryogenic Technologies
2002 - Elsevier BV | Geochimica et Cosmochimica Acta
Hidekazu Kobatake, Katsuo Tsukamoto, Jun Nozawa, K. Nagashima, Hisao Satoh, P. Dold,
Growth conditions and the resultant morphology of cosmic forsterite and enstatite particles condensed from the vapor were ... supersaturation using flash-heating by CO2 laser irradiation. Forsterite particles grew dominantly, followed by a few pyroxenes. No silica minerals were observed. The forsterite morphology changed systematically depending on the temperature (T) ... temperature decreased and the vapor supersaturation increased, the forsterite morphology changed from a bulky type (T=1000– ... the surface of the faceted bulky and platy forsterite particles. Transmission electron microscopic (TEM) observation showed that ...
Tópico(s): Planetary Science and Exploration
2008 - Elsevier BV | Icarus
Zhu Mao, Steven D. Jacobsen, Fengxing Jiang, J.R. Smyth, C. M. Holl, D. J. Frost, T. S. Duffy,
The elastic properties of hydrous forsterite, Mg2 − xSiO4H2x, are relevant to interpreting seismic velocity anomalies in the Earth's mantle. In this study, we used Brillouin scattering to determine the single-crystal elasticity of forsterite with 0.9(1) wt.% H2O (x = 0. ... GPa. Aggregate bulk and shear moduli of hydrous forsterite increase with pressure at a greater rate than ... of the corresponding anhydrous phase. Compared with anhydrous forsterite, we observe a 7% increase in the pressure ... the shear modulus (G0′ = 1.75(5)) for forsterite with near maximum possible water content. Using our ...
Tópico(s): earthquake and tectonic studies
2010 - Elsevier BV | Earth and Planetary Science Letters
Mahshid Kharaziha, Mohammadhossein Fathi,
... deals with the fabrication and characterization of nanostructured forsterite bulk. This material may have better biocompatibility and mechanical properties than coarse grain forsterite for the development of bone tissue engineering materials. Nanostructured forsterite bulks were prepared by two step sintering of sol–gel derived forsterite nanopowder. Their sinterability and mechanical properties were then studied. Biocompatibility of the nanostructured forsterite bulk was also evaluated by cell attachment and ...
Tópico(s): Dental materials and restorations
2010 - Elsevier BV | Journal of the mechanical behavior of biomedical materials/Journal of mechanical behavior of biomedical materials
Gijs D. Mulders, L. B. F. M. Waters, C. Dominik, B. Sturm, J. Bouwman, M. Min, Arnoud P. Verhoeff, B. Acke, J.‐C. Augereau, Neal J. Evans, Th. Henning, G. Meeus, J. Olofsson,
Forsterite is one of the crystalline dust species that is often observed in protoplanetary disks and solar ... crystallinity remains unclear. We aim to characterize the forsterite abundance and spatial distribution in the disk of ... infrared features to model the spatial distribution of forsterite. The temperature-dependent shape of the 69 micron ... possibly farther out at the disk surface. The forsterite is in thermal contact with the other dust ... an upper limit on the iron content of forsterite of 0.3 %. Optical depth effects play a ...
Tópico(s): High-pressure geophysics and materials
2011 - EDP Sciences | Astronomy and Astrophysics
John M. Ferry, T. Ushikubo, John W. Valley,
... the infiltration-driven reaction 2 dolomite + SiO2(aq) = forsterite + 2 calcite + 2 CO2 exhibit correlations among forsterite crystal morphology, size, number density (number of Fo ... oxygen isotope ratio (δ18O). The δ18O of coexisting forsterite, calcite, and dolomite were determined by in situ ... Twin Lakes pendant, Sierra Nevada, California, contains blocky forsterite with the largest average crystal size and the lowest crystal number density. Forsterite and calcite are uniform in δ18O with the ... the Beinn an Dubhaich aureole, Scotland, contains tabular forsterite with intermediate average size and number density. Forsterite ...
Tópico(s): Clay minerals and soil interactions
2011 - Oxford University Press | Journal of Petrology
Tomohiro Ohuchi, Michihiko Nakamura,
... experiments in dunite, clinopyroxenite, and wehrlites with various forsterite/diopside ratios were performed to investigate the effect ... growth (NGG) occurred in dunite, clinopyroxenite, and relatively forsterite-poor wehrlites (≤70 vol.% of forsterite). Grain growth rates of forsterite and diopside in relatively forsterite-poor wehrlites were much slower than those in dunite and clinopyroxenite. In the forsterite-rich wehrlites (≥80 vol.% of forsterite), NGG of diopside and abnormal grain growth (AGG) ...
Tópico(s): Metallurgical Processes and Thermodynamics
2006 - Elsevier BV | Physics of The Earth and Planetary Interiors
D. C. Presnall, Michael J. Walter,
... to determine the pressure‐temperature melting curve of forsterite from 9.7 to 16.5 GPa. At ... congruent melting at lower pressures to incongruent melting (forsterite = periclase + liquid) at higher pressures. The melting curve ... one (15.6 GPa, 2310°C), the phases forsterite, periclase, anhydrous B, and liquid coexist and the melting reaction changes from forsterite = periclase + liquid at lower pressures to forsterite = anhydrous B + liquid at higher pressures. At the other (16.7 GPa, 2315°C), the phases forsterite, modified spinel, anhydrous B, and liquid coexist, and ...
Tópico(s): earthquake and tectonic studies
1993 - American Geophysical Union | Journal of Geophysical Research Atmospheres
Daniel E. Giammar, Robert G. Bruant, Catherine A. Peters,
The products of forsterite dissolution and the conditions favorable for magnesite precipitation have been investigated in experiments conducted at temperature and pressure conditions ... geologic carbon sequestration in deep saline aquifers. Although forsterite is not a common mineral in deep saline ... spectroscopy, and X-ray diffraction. The extent of forsterite dissolution increased with both increasing temperature and PCO2. The release of Mg and Si from forsterite was stoichiometric, but the Si concentration was ultimately ...
Tópico(s): Geological and Geochemical Analysis
2005 - Elsevier BV | Chemical Geology
Kinetics of evaporation of forsterite in hydrogen gas was investigated by high temperature vacuum experiments in the pressure range plausible for the solar nebula. The ... to 10−4 bar. The apparent increase of forsterite evaporation rate with increasing H2 abundance is due ... experimental results were applied to understand behavior of forsterite dusts with time in an abruptly heated model nebula mostly comprising forsterite and H2. The nebular system can be divided ... regime (low dust enrichment), the minimum time for forsterite grains to totally evaporate is estimated as a ...
Tópico(s): Atmospheric chemistry and aerosols
1996 - Elsevier BV | Geochimica et Cosmochimica Acta
... compositions of aqueous fluids in equilibrium with enstatite + forsterite were investigated at temperatures from 900 to 1200 ° ... between the stability fields of enstatite and enstatite + forsterite, and enstatite + forsterite and forsterite. The intersection of these two phase-boundaries near ... the phase boundaries between the enstatite and enstatite + forsterite and between the enstatite + forsterite and forsterite stability fields were taken to represent the concentrations ... concentration of dissolved silica in equilibrium with enstatite + forsterite was obtained combining data from the present study ...
Tópico(s): Iron oxide chemistry and applications
2000 - Mineralogical Society of America | American Mineralogist
Stephan Weinbruch, H. Palme, B. Spettel,
... an ion microprobe. Matrix that accreted to the forsterite grains has a well‐defined unique composition, different ... such as Al, do not quantitatively reside in forsterite; whereas others ( e.g. , Ca) are intrinsic to forsterite. The chondritic refractory element ratios in bulk samples, ... rich glasses may have acted as nuclei for forsterite condensation. Arguments are presented that exclude an origin of refractory forsterite by crystallization from melts with compositions characteristic of Allende chondrules: (a) All forsterite grains have CaO contents between 0.5 and ...
Tópico(s): Geological and Geochemical Analysis
2000 - Wiley | Meteoritics and Planetary Science
Gregory J. Finkelstein, Przemysław Dera, Sandro Jahn, Artem R. Oganov, C. M. Holl, Yu Meng, T. S. Duffy,
Forsterite, Mg2SiO4, the magnesian end-member of the olivine system, is the archetypal example of an orthosilicate ... experiments to 90 GPa on synthetic end-member forsterite to study its equation of state and phase transitions. Upon room-temperature compression, the forsterite structure is observed to 48 GPa. By fitting ... GPa, a phase transition to a new structure (forsterite II) occurs, followed by a second transition to forsterite III at 58 GPa. Forsterite III undergoes no additional phase transitions until at ...
Tópico(s): Geological and Geochemical Analysis
2014 - Mineralogical Society of America | American Mineralogist
K. M. Maaskant, B. L. de Vries, M. Min, L. B. F. M. Waters, C. Dominik, Frank Molster, A. G. G. M. Tielens,
... mid- and far- infrared emission features produced by forsterite dust grains. The spectral features contain information about the forsterite temperature, chemical composition and grain size. We aim ... be used to constrain the physical locations of forsterite in disks. We check for consistency between two independent forsterite temperature measurements: the 23/69 feature strength ratio ... study the effect of disk properties to the forsterite spectral features. Temperature-dependent forsterite opacities were considered ...
Tópico(s): Molecular Spectroscopy and Structure
2014 - EDP Sciences | Astronomy and Astrophysics
F.S. Sayyedan, M. H. Fathi, H. Edris, Ali Doostmohammadi, V. Mortazavi, Amir Reza Hanifi,
... this study was to assess the effect of forsterite nanoparticles on the mechanical properties of glass ionomer cements (GICs). So, forsterite nanoparticles were produced by a sol–gel process ... the phase composition and the grain size of forsterite nanoparticles. Compressive strength (CS), three-point flexural strength ( ... tensile strength (DTS) of the prepared glass ionomer-forsterite nanocomposites were measured. Analysis of variance (ANOVA) was ... XRD analysis confirmed the synthesis of pure nanocrystalline forsterite particles. Statistical analysis showed a significant difference between ...
Tópico(s): Bone Tissue Engineering Materials
2014 - Elsevier BV | Ceramics International
Produção Nacional
Revisado por pares
Cláudio M. D. de Souza, Cristine Elizabeth Alvarenga Carneiro, João Paulo T. Baú, Antônio Carlos Saraiva da Costa, Flávio F. Ivashita, Andrea Paesano, Eduardo Di Mauro, Henrique de Santana, Nils G. Holm, Anna Neubeck, Cássia Thaïs Bussamra Vieira Zaia, Dimas Augusto Morozin Zaia,
Abstract In the present work, the interactions between forsterite-91 with distilled water and forsterite-91 with artificial seawater were studied at two ... pH (2.0) due to the dissolution of forsterite-91 in distilled water and artificial seawater. Thus, ... PZC decreased and the pH IEP increased when forsterite-91 was treated with distilled water and artificial ... ray diffractograms showed halite in the samples of forsterite-91 mixed with artificial seawater. The presence of ... or adsorption of ions on the surface of forsterite-91 could affect the synthesis of magnetite and ...
Tópico(s): Photosynthetic Processes and Mechanisms
2013 - Cambridge University Press | International Journal of Astrobiology
B. Sturm, J. Bouwman, Th. Henning, Neal J. Evans, L. B. F. M. Waters, E. F. van Dishoeck, J. D. Green, J. Olofsson, G. Meeus, K. M. Maaskant, C. Dominik, J.‐C. Augereau, Gijs D. Mulders, B. Acke, B. Merín, Gregory J. Herczeg,
... the 69mu emission band of the crystalline silicate forsterite. Aims: This work provides an overview of the 69mu forsterite bands in the DIGIT sample. We aim to derive the temperature and composition of the forsterite grains. With this information, constraints can be placed on the spatial distribution of the forsterite in the disk and its formation history. Methods: ... and strength of the 69mu band to the forsterite bands at shorter wavelengths. Results: A total of ... 69mu emission band that can be attributed to forsterite. With the exception of the T-Tauri star ...
Tópico(s): Stellar, planetary, and galactic studies
2013 - EDP Sciences | Astronomy and Astrophysics
Virginie Baptiste, Sylvie Demouchy, Shantanu Keshav, Fleurice Parat, Nathalie Bolfan‐Casanova, Pierre Condamine, Patrick Cordier,
... occur between a volatile-rich kimberlitic liquid and forsterite, results of high-pressure and high-temperature experiments ... CaO-MgO-Al2O3-SiO2-CO2-H2O and synthetic forsterite single crystals were chosen as a first simplification ... the concentrations of OH in the crystallographically oriented forsterite. Scanning electron microscopy, electron backscattered diffraction, electron microprobe ... run products. After 5 and 23 h, a forsterite overgrowth crystallized with the same orientation as the initial forsterite single crystal. The kimberlitic liquid has crystallized as ...
Tópico(s): earthquake and tectonic studies
2015 - Mineralogical Society of America | American Mineralogist
Mitra Kheirkhah, Mohammadhossein Fathi, Hamid Reza Salimijazi, Mehdi Razavi,
... of this research was the preparation of the forsterite (Mg2SiO4) coating on the surface of 316L stainless ... 316L SS) substrate. For this purpose, the nanostructured forsterite was coated on the 316L SS substrate using ... SBF). The in vitro bioactivity evaluation of the forsterite coated samples was conducted by soaking the samples ... results showed that, a crack-free and homogeneous forsterite coating with the crystallite size of around 40 ... SS substrate. The corrosion current density of the forsterite coated samples was lesser than that of the ...
Tópico(s): Corrosion Behavior and Inhibition
2015 - Elsevier BV | Surface and Coatings Technology
T. Suhasaria, J. D. Thrower, H. Zacharias,
... thermal desorption of ammonia (NH3) from single crystal forsterite (010) has been investigated using temperature-programmed desorption. ... probed by the use of a rough cut forsterite surface prepared from the cleaved forsterite sample. Several approaches have been used to extract ... sensitive to the surface roughness with the cut forsterite surface displaying a significantly broader distribution of desorption energies compared to the cleaved forsterite surface. The cut forsterite surface exhibits sites with ...
Tópico(s): Atmospheric Ozone and Climate
2015 - Oxford University Press | Monthly Notices of the Royal Astronomical Society
Priscille Cuvillier, Hugues Leroux, Damien Jacob, Pierre Hirel,
... 50 ). Fayalitic olivines also occur as rims around forsterite grains in chondrules and isolated forsterite fragments in the matrix or as veins cross‐ ... therefore a strong chemical disequilibrium between the large forsterite grains and the fayalite‐rich fine‐grained matrix. ... the fayalite‐rich matrix grains and interfaces with forsterite fragments. We confirm that fayalitic grains in the matrix and fayalitic rims around forsterite fragments have the same properties, suggesting a common ... body of Allende. Composition profiles at the rim/forsterite interfaces exhibit a plateau in the rim (typically ...
Tópico(s): Geological and Geochemical Analysis
2015 - Wiley | Meteoritics and Planetary Science