Synthesis, structure, thermodynamic properties, and stability relations of K-cymrite, K[AlSi 3 O 8 ]·H 2 O

Faßhauer, Detlef W.; Chatterjee, Niranjan D.; Marler, Β.

doi:10.1007/s002690050060

Cited by 40 publications

(37 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Bands at 3531 and 3603 cm −1 as occurring in the spectra of the NH 4 -hollandite and NH 4 -Si-wadeite-bearing samples represent the two OH-stretching bands of OH-topaz (Wunder et al 1993). NH 4 -cymrite contains molecular water, consequently, in the NH 4 -cymritebearing sample a H 2 O bending mode at 1606 cm −1 and the OH-stretching modes at 3533 and 3621 cm −1 are present, the positions are the same as observed by Fasshauer et al (1997) for K-cymrite. According to that study the shoulder, which can be observed at 3433 cm −1 , is also due to H 2 O.…”

Section: Resultssupporting

confidence: 67%

“…K-hollandite appears also as a reaction product of phengite breakdown in metapelitic and metabasaltic bulk compositions at pressures higher than 8 to 11 GPa, 750 to 900 • C (Domanik and Holloway 1996;Schmidt and Poli 1998;Poli and Schmidt 2002) and is probably stable up to 95 GPa, 2300 • C (Konzett and Fei 2000;Tutti et al 2001). Therefore, K-hollandite is believed to be the main K-rich solid-phase reservoir for potassium through the transition zone to the lower mantle in silicate compositional systems because K-Al-bearing silicates react to yield K-hollandite with increasing pressure (Harlow Fasshauer et al (1997), for K-Si-wadeite and K-hollandite from Yong et al (2008). Upper temperature and pressure stabilities of K-phengite determined for natural samples of metapelitic bulk compositions (Poli and Schmidt 2002), stabilities of SiO 2 polymorphs from Akaogi et al (1995).…”

Section: Introductionmentioning

confidence: 99%

“…In a status report on the stability of Kphases at mantle conditions, Harlow and Davies (2004) documented a number of K-bearing silicates that may form at higher pressure, mainly based on a summary of experimental results. In a wet system, K-feldspar may be replaced by K-cymrite [K IV Al IV Si 3 O 8 · H 2 O] above about 2.5 GPa (Fasshauer et al 1997; Fig. 1).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

High-pressure ammonium-bearing silicates: Implications for nitrogen and hydrogen storage in the Earth's mantle

Watenphul

Wunder

Heinrich

2009

American Mineralogist

View full text Add to dashboard Cite

The ammonium analogues of the high-pressure potassium-bearing silicate phases K-hollandite, K-Si-wadeite, K-cymrite, and phengite were synthesized in the system (NH 4 Ammonium in eclogite facies metasediments is mainly bound in micas and concentrations may reach up to a few thousand ppm. It can be stored to greater depths in high-pressure potassium silicates during ongoing subduction. This possibly provides an important mechanism for nitrogen and hydrogen transport into the deeper mantle.

show abstract

Section: Resultssupporting

confidence: 67%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

High-pressure ammonium-bearing silicates: Implications for nitrogen and hydrogen storage in the Earth's mantle

Watenphul

Wunder

Heinrich

2009

American Mineralogist

View full text Add to dashboard Cite

show abstract

“…Si NMR study revealed that the Si -Al distribution in the tetrahe dral sites of K -cymrite is disordered, consistent with the crystal structural study of a synthetic sample by Fasshauer et al (1997). Although the states of Si -Al ordering for natural samples are unknown, close agreement of the peak positions for the two most intense Raman peaks between natural and synthetic kokchetavite suggests that this effect is also likely insignifi cant.…”

supporting

confidence: 59%

“…It is isostructural with natural cymrite (BaAl 2 Si 2 O 8 ·H 2 O). Both phases have a unique crystal structure consisting of double -layers of Si(Al)O 4 tetrahedra that are linked together by large cations (K or Ba), with water molecules occupying cages within the double -layers (Fasshauer et al, 1997). When heated at ambient pressure, K -cymrite dehydrates to a metastable anhydrous hexagonal KAlSi 3 O 8 phase while retaining its original structure (Thompson et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

Raman and NMR spectroscopic characterization of high-pressure K-cymrite (KAlSi3O8.H2O) and its anhydrous form (kokchetavite)

Kanzaki

Xue

Amalberti

et al. 2012

Journal of Mineralogical and Petrological Sciences

View full text Add to dashboard Cite

To facilitate identification of high -pressure K -cymrite (KAlSi 3 O 8 ·H 2 O) phase and its anhydrous form (kokche tavite) in natural rocks, we have synthesized both phases and have characterized them by micro -Raman and NMR spectroscopy. K -cymrite was synthesized at 5 GPa and 800 °C. Kokchetavite was obtained by dehydrating K -cymrite at ambient pressure and 550 °C. The . The Raman spectrum for kokchetavite is consistent with that previously reported for a natural sample found as inclusions in clinopyroxenes and garnets in a garnet -pyroxene rock. However, the data for K -cymrite are inconsistent with the Raman features of a previously reported "relict K -cymrite in K -feldspar" from an eclogite. Pressure -and temperature -dependencies of the Raman shifts for the strongest peak of both phases are also reported.

show abstract

Nuclear Magnetic Resonance of Geological Materials and Glasses

Moran

Howe

2000

Encyclopedia of Analytical Chemistry

View full text Add to dashboard Cite

This article concerns the application of nuclear magnetic resonance (NMR) spectroscopic techniques to the analysis of geological materials and glasses. It includes inorganic minerals and glasses, but does not cover soils and clay minerals to any extent. The first part presents an overview of solid‐state NMR experiments applicable to inorganic solids. The range of nuclei accessible by NMR and the particular requirements for obtaining good spectra of more difficult nuclei, including quadrupolar nuclei, are discussed. The experimental conditions under which solid‐state NMR can provide quantitative analytical measurements are also considered. NMR spectroscopy provides element‐specific speciation and structural information including coordination environment and bond distances. It is particularly valuable for the analysis of amorphous and partially crystalline materials not amenable to structure determination by X‐ray diffraction. NMR can detect and quantify materials containing multiple phases and can be used for in situ monitoring of phase transitions. It provides qualitative and quantitative speciation information for framework nuclei in glasses and is also capable of characterizing the dynamic behavior of mobile ions and solvent through relaxation, diffusion and chemical exchange experiments. Thus it has become an important technique for the study of hydrous minerals and gels and for ion‐conducting glasses. The sensitivity of NMR varies considerably, depending on the nucleus observed, its abundance and its chemical environment. NMR sensitivities and detection limits cannot compete with elemental analytical techniques such as X‐ray fluorescence. In addition, quantitation in solids requires careful control of experimental parameters and careful calibration to avoid artifacts. However, the selectivity of NMR as an analytical technique is unsurpassed and the development of specialist pulse sequences to measure specific local interactions in solids makes it particularly well suited to the analysis of geological materials and glasses. NMR imaging enables structural information to be resolved in three dimensions, although resolution in solid‐state imaging is limited to tens of micrometers at best owing to the broader line widths and lower signal‐to‐noise ratios compared with liquids. However, capabilities in this field are being extended all the time and the application of NMR imaging techniques in materials analysis is expanding steadily. An alternative to conventional imaging is NMR force microscopy, which shows potential for surface mapping at higher resolutions. The applications section is organized on the basis of the materials being analyzed. Within each section, NMR techniques are classified according to the observed nuclei. The emphasis is on more recent applications and on developments leading to enhanced resolution and sensitivity. Silicates and aluminosilicates represent the largest class of applications, followed by phosphate, borate and other oxide glasses. Sol–gel materials and the reactions leading to gel formation are also discussed, as are hydrous materials more generally. The other important areas of application reviewed are minerals, ceramics, high‐temperature melts and ion‐conducting glasses. Finally, the applications of NMR imaging in this field, although sparse at present, are potentially very great. This is illustrated by two major areas of application to date, namely the imaging of bone minerals and cement and concrete.

show abstract

Synthesis, structure, thermodynamic properties, and stability relations of K-cymrite, K[AlSi 3 O 8 ]·H 2 O

Cited by 40 publications

References 14 publications

High-pressure ammonium-bearing silicates: Implications for nitrogen and hydrogen storage in the Earth's mantle

High-pressure ammonium-bearing silicates: Implications for nitrogen and hydrogen storage in the Earth's mantle

Raman and NMR spectroscopic characterization of high-pressure K-cymrite (KAlSi<sub>3</sub>O<sub>8</sub><sup>.</sup>H<sub>2</sub>O) and its anhydrous form (kokchetavite)

Nuclear Magnetic Resonance of Geological Materials and Glasses

Contact Info

Product

Resources

About