File(s) under permanent embargo
Site occupancies by iron in nontronites
journal contribution
posted on 2002-04-01, 00:00 authored by Will GatesWill Gates, P G Slade, A Manceau, B LansonTwelve nontronites and two ferruginous smectites have been characterized with respect to Fe 3+ occupancy of tetrahedral sites. The techniques used were near infrared, Fe-K X-ray absorption near-edge and X-ray absorption fine-structure spectroscopies, along with two X-ray diffraction techniques. The results show that calculations of the structural formulae of many nontronites should be adjusted to include Fe 3+ in tetrahedral sites. The nontronite from Spokane County, Washington, (∼44% Fe 2 O 3 ) is essentially an end-member with its non-siliceous tetrahedral sites occupied by Fe 3+ . Samples with chemical compositions similar to Garfield nontronite (∼36.5% Fe 2 O 3 ) may have small amounts ( < 5% of total Fe 3+ ) of tetrahedral Fe 3+ . Tetrahedral Fe 3+ is unlikely to be present in samples containing less than ∼34% Fe 2 O 3 .
History
Journal
Clays and clay mineralsVolume
50Issue
2Pagination
223 - 239Publisher
The Clay Minerals SocietyLocation
[Chantilly, Va.]Publisher DOI
ISSN
0009-8604Language
engPublication classification
C1.1 Refereed article in a scholarly journalCopyright notice
2002, The Clay Minerals SocietyUsage metrics
Categories
Keywords
Chemical AnalysesTetrahedral FeStructural FormulaScience & TechnologyPhysical SciencesLife Sciences & BiomedicineChemistry, PhysicalGeosciences, MultidisciplinaryMineralogySoil ScienceChemistryGeologyAgricultureEXAFSnear IRnontronitesoctahedral Fesite occupancysmectitesXANESX-ray diffractionMOSSBAUER-SPECTROSCOPYTRIOCTAHEDRAL MICASTETRAHEDRAL FE-3+GARFIELD NONTRONITELAYERED STRUCTURESPOLARIZED EXAFSX-RAYSDIFFRACTIONFE3+VERMICULITEGeology
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC