Abstract
Infrared spectroscopic quantification of traces of OH and H2O in minerals and glasses is based on the Beer Lambert law A = ε·c·t, where ε is the molar absorption coefficient. Numerous experimental and theoretical studies show that ε generally increases with decreasing wavenumbers. However, this general trend seems to be valid only for hydrous minerals and glasses and should not be applied to water quantification in nominally anhydrous minerals (NAMs) that incorporate traces of water in their structures. In this study, we analyze ε-values from literature data and propose that within a polymorphic mineral series of the same composition ε negatively correlates with the molar volume and positively correlates with the density of the respective mineral phase. To test this hypothesis, we determined ε-values for synthetic hydrous ringwoodite samples ranging in composition from XMg = 0.0 to 0.6 by combining results of FTIR-spectroscopy with those of secondary ion mass spectrometry. The ε-values plot well below the general calibration curves but follow the same trend, i.e., they increase with decreasing wavenumbers of the OH bands from 59 000 ± 6000 for the Fe end-member to 85 800 ± 10 000 L/mol(H2O)/cm-2 for the Mg-richest sample. From this relation we can predict an absorption coefficient for the iron-free Mg end-member as 100 000 ± 7000 L/mol(H2O)/cm-2. This value together with ε-values for forsterite and wadsleyite taken from literature confirm the proposed correlation with the molar volume and density within this polymorphic series. This allows us to predict absorption coefficients for some minerals, where coefficients for one or better two of their polymorphs, either high- or low-pressure, are available.
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- TEM-assisted dynamic scanning force microscope imaging of (001) antigorite: Surfaces and steps on a modulated silicate
- PH₂O-dependent structural phase transitions in the zeolite mesolite: Real- and reciprocal-space crystal structure refinements
- The crystal structure of esperite, with a revised chemical formula, PbCa2(ZnSiO4)3, isostructural with beryllonite
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- Coulsellite, CaNa3AlMg3F14, a rhombohedral pyrochlore with 1:3 ordering in both A and B sites, from the Cleveland Mine, Tasmania, Australia
- Synthesis and characterization of zeolite 4A-type desiccant from kaolin
- Effect of iron on the compressibility of hydrous ringwoodite
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- Rate of antigorite dehydration at 2 GPa applied to subduction zones
- IR absorption coefficients for water in nominally anhydrous high-pressure minerals
- Experimental techniques for determining tin solubility in silicate melts using silica capsules in 1 atm furnaces and rhenium capsules in the piston cylinder
- Cassiterite-saturated minimum melting behavior within Sn-SnO2-SiO2 at 1 atm and 10 kbar
- Cr-bearing tourmaline associated with emerald deposits from Swat, NW Pakistan: Genesis and its exploration significance
- Mechanism and kinetics of reduction of a FeO-Fe2O3-CaO-MgO aluminosilicate melt in a high-CO-activity environment
- Biodurability of chrysotile and tremolite asbestos in simulated lung and gastric fluids
- High-pressure behavior of Ca/Na clinopyroxenes: The effect of divalent and trivalent 3d-transition elements
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- An X-ray Rietveld and infrared spectral study of the Na2(Mn1–xM2+x )Fe2+Fe3+(PO4)3 (x = 0 to 1 and M2+ = Mg, Cd) alluaudite-type solid solutions
- Dissolution kinetics of anorthite in a supercritical CO2–water system
- Evaluation of the elasticity normal to the basal plane of non-expandable 2:1 phyllosilicate minerals by nanoindentation
- 57Fe Mössbauer spectroscopy and electrical resistivity studies on naturally occurring native iron under high pressures up to 9.1 GPa
- Letter. Discreditation of paraspurrite
- Letter. High-pressure magnetic transition in hcp-Fe
- Letter. Reduced As components in highly oxidized environments: Evidence from full spectral XANES imaging using the Maia massively parallel detector
- Letter. FTIR spectroscopy with a focal plane array detector: A novel tool to monitor the spatial OH-defect distribution in single crystals applied to synthetic enstatite
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Articles in the same Issue
- TEM-assisted dynamic scanning force microscope imaging of (001) antigorite: Surfaces and steps on a modulated silicate
- PH₂O-dependent structural phase transitions in the zeolite mesolite: Real- and reciprocal-space crystal structure refinements
- The crystal structure of esperite, with a revised chemical formula, PbCa2(ZnSiO4)3, isostructural with beryllonite
- Dendritic zircon formation by deterministic volume-filling fractal growth: Implications for the mechanisms of branch formation in dendrites
- Enthalpies of formation of pyrrhotite Fe1–0.125xS (0 ≤ x ≤ 1) solid solutions
- Crystal chemistry of synthetic lawsonite solid-solution series CaAl2[(OH)2/Si2O7]·H2O– SrAl2[(OH)2/Si2O7]·H2O and the Cmcm–P21/m phase transition
- Coulsellite, CaNa3AlMg3F14, a rhombohedral pyrochlore with 1:3 ordering in both A and B sites, from the Cleveland Mine, Tasmania, Australia
- Synthesis and characterization of zeolite 4A-type desiccant from kaolin
- Effect of iron on the compressibility of hydrous ringwoodite
- Kapundaite, (Na,Ca)2Fe4 3+(PO4)4(OH)3·5H2O, a new phosphate species from Toms quarry, South Australia: Description and structural relationship to mélonjosephite
- Rate of antigorite dehydration at 2 GPa applied to subduction zones
- IR absorption coefficients for water in nominally anhydrous high-pressure minerals
- Experimental techniques for determining tin solubility in silicate melts using silica capsules in 1 atm furnaces and rhenium capsules in the piston cylinder
- Cassiterite-saturated minimum melting behavior within Sn-SnO2-SiO2 at 1 atm and 10 kbar
- Cr-bearing tourmaline associated with emerald deposits from Swat, NW Pakistan: Genesis and its exploration significance
- Mechanism and kinetics of reduction of a FeO-Fe2O3-CaO-MgO aluminosilicate melt in a high-CO-activity environment
- Biodurability of chrysotile and tremolite asbestos in simulated lung and gastric fluids
- High-pressure behavior of Ca/Na clinopyroxenes: The effect of divalent and trivalent 3d-transition elements
- Uvarovite from chromite-bearing ultramafic intrusives, Orissa, India, a crystal-chemical characterization using 57Fe Mössbauer spectroscopy
- An X-ray Rietveld and infrared spectral study of the Na2(Mn1–xM2+x )Fe2+Fe3+(PO4)3 (x = 0 to 1 and M2+ = Mg, Cd) alluaudite-type solid solutions
- Dissolution kinetics of anorthite in a supercritical CO2–water system
- Evaluation of the elasticity normal to the basal plane of non-expandable 2:1 phyllosilicate minerals by nanoindentation
- 57Fe Mössbauer spectroscopy and electrical resistivity studies on naturally occurring native iron under high pressures up to 9.1 GPa
- Letter. Discreditation of paraspurrite
- Letter. High-pressure magnetic transition in hcp-Fe
- Letter. Reduced As components in highly oxidized environments: Evidence from full spectral XANES imaging using the Maia massively parallel detector
- Letter. FTIR spectroscopy with a focal plane array detector: A novel tool to monitor the spatial OH-defect distribution in single crystals applied to synthetic enstatite
- Letter. Akaogiite: An ultra-dense polymorph of TiO2 with the baddeleyite-type structure, in shocked garnet gneiss from the Ries Crater, Germany