Abstract
Ca-Na ordering and structural polarity of subcells in an intermediate plagioclase with modulated structure have been observed using Z-contrast imaging with an aberration-corrected scanning transmission electron microscope. Neighboring lamellar domains with I1̄ symmetry are related by inversion twin operation, instead of anti-phase domain boundaries (or APBs) as in all previously reported structure models. The boundaries between lamellar domains have I1̄ symmetry instead of C1̄ symmetry. Modulated plagioclase has unique Ca-Na and Al-Si ordering structure that is different from those in end-member structures of anorthite and low albite. The modulated structures of intermediate plagioclase are not metastable structures formed during phase transition, but instead thermodynamically stable structures at low temperature due to Ca-Na ordering within the subcells with I1 symmetry.
© 2015 by Walter de Gruyter Berlin/Boston
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- Anhydrite: An important sulfur binder limiting the climatic impact of subaerial volcanic eruptions
- Tweed, twins, and holes
- The chemical behavior of fluids released during deep subduction based on fluid inclusions
- In situ observation of the pyroxene-majorite transition in Na2MgSi5O12 using synchrotron radiation and Raman spectroscopy of Na-majorite
- Prevalence of growth twins among anhedral plagioclase microlites
- Intrinsic conditions of magma genesis at the Lunar Crater Volcanic Field (Nevada), and implications for internal plumbing and magma ascent
- A rock fragment related to the magnesian suite in lunar meteorite Allan Hills (ALHA) 81005
- Trinitite redux: Mineralogy and petrology
- Pauloabibite, trigonal NaNbO3, isostructural with ilmenite, from the Jacupiranga carbonatite, Cajati, São Paulo, Brazil
- Kojonenite, a new palladium tin telluride mineral from the Stillwater Layered Igneous Intrusion, Montana, U.S.A.
- Cathodoluminescence dependence on feldspar mineral structure and implications for forensic geology
- Non-invasive assessment of the formation of tourmaline nodules by X-ray microtomography and computer modeling
- Alkali influence on the water speciation and the environment of protons in silicate glasses revealed by 1H MAS NMR spectroscopy
- Carbonate mineralization in percolated olivine aggregates: Linking effects of crystallographic orientation and fluid flow
- The catalytic effect of bound extracellular polymeric substances excreted by anaerobic microorganisms on Ca-Mg carbonate precipitation: Implications for the “dolomite problem”
- Experimental study along the magnesio-hornblende–glaucophane join
- Direct observation of Ca-Na ordering and structure polarity in Ca-rich intermediate plagioclase feldspar with incommensurate modulated structure
- Stability and adhesion of calcite/montmorillonite assembly
- Experimental and modeled chlorine solubilities in aluminosilicate melts at 1 to 7000 bars and 700 to 1250 °C: Applications to magmas of Augustine Volcano, Alaska
- Cation order-disorder in Fe-bearing pyrope and grossular garnets: A 27Al and 29Si MAS NMR and 57Fe Mössbauer spectroscopy study
- Trace and minor elements in galena: A reconnaissance LA-ICP-MS study
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- Mössbauer spectroscopic study of natural eosphorite, [(Mn,Fe)AlPO4(OH)2H2O]
- P-V-T equation of state of Ca3Cr2Si3O12 uvarovite garnet by using a diamond-anvil cell and in-situ synchrotron X-ray diffraction
- Possible new Ca-REE-Bi phosphate minerals from a tungsten-rich calcsilicate skarn, Sierra Nevada Mountains, California
- Klebelsbergite, Sb4O4SO4(OH)2: Stability relationships, formation in Nature, and refinement of its structure
- Balestraite, KLi2VSi4O10O2, the first member of the mica group with octahedral V5+
- Prediction of enthalpies of formation of hydrous sulfates
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- New Mineral Names
- Book Review
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