Nature of rehydroxylation in dioctahedral 2:1 layer clay minerals
-
Arkadiusz Derkowski
,
Victor A. Drits
Abstract
Rehydroxylation of the previously dehydroxylated dioctahedral 2:1 layer clay mineral occurs preferentially in specific sites within the former octahedral sheet. The rehydroxylation of dehydroxylated Al-rich and Al,Mg-rich 2:1 layers occurs as trans-vacant (tv) structural arrangements, regardless of whether the initial structure was tv or cis-vacant (cv). In nontronite (Fe-rich 2:1 layer clay), the dehydroxylate pseudo-cv structure is probably directly reconstructed into the rehydroxylated cv structure without migration of octahedral cations. Rehydroxylation occurs preferentially in the R3+-Or-R3+ former octahedral structural arrangements (Or = residual oxygen) over R2+-Or-R (R = R3+ or R2+ = Al3+, Fe3+ or Mg2+, Fe2+). In the case of the R2+ octahedral substitution, the interlayer cation is attracted to the electrostatically undersaturated residual oxygen of the R2+-Or-R arrangement, which blocks the ability of water molecules to pass through the ditrigonal cavity and rehydroxylate the previously dehydroxylated local arrangement. The pyrophyllite-like type of octahedral R3+-Or-R3+ arrangements, formed due to the lack of tetrahedral substitution and resulting in the absence of interlayer cations, is thus favored for rehydroxylation over the mica-like R3+-Or-R3+ arrangements where Al occurs in the tetrahedral sheet. The valence of the interlayer cation and the charge density of the 2:1 layer clay mineral, which controls the interlayer cation content, also affect the degree of rehydroxylation.
Dehydroxylated 2:1 layer minerals with a high-rehydroxylation potential, including beidellite and illite, use all the adsorbed water molecules that persist above 200 °C for rehydroxylation; the water vapor from the ambient environment also becomes a source of H2O molecules for rehydroxylation. The high demand for water molecules to use for rehydroxyltion results in a noticeable gain of mass in the temperature interval between 200 and 350 °C even during heating.
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Veatchite: Structural relationships of the three polytypes
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- Zaccagnaite-3R, a new Zn-Al hydrotalcite polytype from El Soplao cave (Cantabria, Spain)
- Incorporation of Si into TiO2 phases at high pressure
- TOF-SIMS and electron microprobe investigations of zoned magmatic orthopyroxenes: First results of trace and minor element analysis with implications for diffusion modeling
- Titanium in muscovite, biotite, and hornblende: Modeling, thermometry, and rutile activities of metapelites and amphibolites
- Polysaccharide-catalyzed nucleation and growth of disordered dolomite: A potential precursor of sedimentary dolomite
- High-pressure and high-temperature phase transitions in FeTiO3 and a new dense FeTi3O7 structure
- Compressibility and thermal expansion of hydrous ringwoodite with 2.5(3) wt% H2O
- Vibrational and elastic properties of ferromagnesite across the electronic spin-pairing transition of iron
- Electronic spin states of ferric and ferrous iron in the lower-mantle silicate perovskite
- Experimental VNIR reflectance spectroscopy of gypsum dehydration: Investigating the gypsum to bassanite transition
- Nature of rehydroxylation in dioctahedral 2:1 layer clay minerals
- Thermal behavior of afghanite, an ABABACAC member of the cancrinite group
- Experimental incorporation of Th into xenotime at middle to lower crustal P-T utilizing alkali-bearing fluids
- Sol-gel synthesis of nanocrystalline fayalite (Fe2SiO4)
- The heat capacity of fayalite at high temperatures
- Structural trends for celestite (SrSO4), anglesite (PbSO4), and barite (BaSO4): Confirmation of expected variations within the SO4 groups
- The dehydroxylation of serpentine group minerals
- Formation of nanoscale Th-coffinite
- Magnetic and low-temperature structural behavior of clinopyroxene-type FeGeO3: A neutron diffraction, magnetic susceptibility, and 57Fe Mössbauer study
- Crystal structure and thermal expansion of aragonite-group carbonates by single-crystal X-ray diffraction
- The lower-pressure stability of glaucophane in the presence of paragonite and quartz in the system Na2O-MgO-Al2O3-SiO2-H2O
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- The crystal structure of metanatroautunite, Na[(UO2)(PO4)](H2O)3, from the Lake Boga Granite, Victoria, Australia
- Petedunnite (CaZnSi2O6): Stability and phase relations in the system CaO-ZnO-SiO2
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Articles in the same Issue
- Veatchite: Structural relationships of the three polytypes
- Falsterite, Ca2MgMn2+2 (Fe2+0.5Fe3+0.5)4Zn4(PO4)8(OH)4(H2O)14, a new secondary phosphate mineral from the Palermo No. 1 pegmatite, North Groton, New Hampshire
- Pavlovskyite Ca8(SiO4)2(Si3O10): A new mineral of altered silicate-carbonate xenoliths from the two Russian type localities, Birkhin massif, Baikal Lake area and Upper Chegem caldera, North Caucasus
- Zaccagnaite-3R, a new Zn-Al hydrotalcite polytype from El Soplao cave (Cantabria, Spain)
- Incorporation of Si into TiO2 phases at high pressure
- TOF-SIMS and electron microprobe investigations of zoned magmatic orthopyroxenes: First results of trace and minor element analysis with implications for diffusion modeling
- Titanium in muscovite, biotite, and hornblende: Modeling, thermometry, and rutile activities of metapelites and amphibolites
- Polysaccharide-catalyzed nucleation and growth of disordered dolomite: A potential precursor of sedimentary dolomite
- High-pressure and high-temperature phase transitions in FeTiO3 and a new dense FeTi3O7 structure
- Compressibility and thermal expansion of hydrous ringwoodite with 2.5(3) wt% H2O
- Vibrational and elastic properties of ferromagnesite across the electronic spin-pairing transition of iron
- Electronic spin states of ferric and ferrous iron in the lower-mantle silicate perovskite
- Experimental VNIR reflectance spectroscopy of gypsum dehydration: Investigating the gypsum to bassanite transition
- Nature of rehydroxylation in dioctahedral 2:1 layer clay minerals
- Thermal behavior of afghanite, an ABABACAC member of the cancrinite group
- Experimental incorporation of Th into xenotime at middle to lower crustal P-T utilizing alkali-bearing fluids
- Sol-gel synthesis of nanocrystalline fayalite (Fe2SiO4)
- The heat capacity of fayalite at high temperatures
- Structural trends for celestite (SrSO4), anglesite (PbSO4), and barite (BaSO4): Confirmation of expected variations within the SO4 groups
- The dehydroxylation of serpentine group minerals
- Formation of nanoscale Th-coffinite
- Magnetic and low-temperature structural behavior of clinopyroxene-type FeGeO3: A neutron diffraction, magnetic susceptibility, and 57Fe Mössbauer study
- Crystal structure and thermal expansion of aragonite-group carbonates by single-crystal X-ray diffraction
- The lower-pressure stability of glaucophane in the presence of paragonite and quartz in the system Na2O-MgO-Al2O3-SiO2-H2O
- Coralloite, Mn2+Mn23+(AsO4)2(OH)2·4H2O, a new mixed valence Mn hydrate arsenate: Crystal structure and relationships with bermanite and whitmoreite mineral groups
- The crystal structure of metanatroautunite, Na[(UO2)(PO4)](H2O)3, from the Lake Boga Granite, Victoria, Australia
- Petedunnite (CaZnSi2O6): Stability and phase relations in the system CaO-ZnO-SiO2
- Revision of the crystal structure and chemical formula of weeksite, K2(UO2)2(Si5O13)·4H2O
- Electron backscatter diffraction (EBSD) analyses of phyllosilicates in petrographic thin sections
