Raman microprobe spectra of individual microcrystals and fibers of talc, tremolite, and related silicate minerals

Blaha, J. J.; Rosasco, G. J.

doi:10.1021/ac50029a018

Cited by 76 publications

(58 citation statements)

References 14 publications

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“…This band was assigned to internal movements of octahedral sheets. Such a band has also been found in talc (Blaha and Rosasco, 1978;Rosasco and Blaha, 1980). A weak band at about 280 cm -~ was assigned by Ishii et al (1967) and Shirozu (1985) to tetrahedral movements with the symmetry species E13.…”

Section: Bands In the 1300-50-cm -S Spectral Rangementioning

confidence: 53%

Structure-Composition Relationships in Trioctahedral Chlorites: A Vibrational Spectroscopy Study

Prieto

Dubessy

Cathelineau

1991

Clays and clay miner.

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Abstract--Raman and Fourier-transformed infrared spectra of natural trioctahedral chlorites of polytype IIb were obtained for a series of samples characterized by distinct Fe/(Fe + Mg) and Si/Al ratios ranging, respectively, from 0.04 to 0.94 and from 5.18 to 1.86. All samples were characterized by X-ray powder diffraction, and quantitative electron microprobe analysis. In the 3683-3610-cm -~ spectral range, the wave number of the OH-stretching band from the 2: l layer (band I) decreased with an increase of iron content at constant Al(IV) content. The more intense bands II and III at about 3600 cm l and 3500 cm -1, were assigned to hydroxyl groups involved in hydrogen bonds: (SiSi)O... HO, with the hydrogen bonds being roughly perpendicular to the basal plane, and (SiA1)O... HO, respectively. At higher tetrahedral A1 and octahedral Fe contents, spectra exhibited OH-bands II and III, respectively, at a lower frequency. Band III intensity increased and band II was enlarged for chlorites displaying higher AI(IV) contents.In the 1300-1350-cm l spectral range, most infrared spectra displayed intense bands at 1090, 1050, 990, and 960 cm ~, which were assigned to T-O stretching of symmetry species A1 and El. The second type of bands observed both in Raman and infrared spectra were at about 650-800 cm ~; they were assigned to OH vibrations and were strongly dependent on the composition of the interlayer octahedral sheet, especially on the Fe content.

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Section: Bands In the 1300-50-cm -S Spectral Rangementioning

confidence: 53%

Structure-Composition Relationships in Trioctahedral Chlorites: A Vibrational Spectroscopy Study

Prieto

Dubessy

Cathelineau

1991

Clays and clay miner.

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“…Difference 1 cm -1 may be caused either by substitution (Farmer 1974;Yariv and HellerKallei 1975) or by the structural differences between lizardite and chrysotile. Structural differences are both long-range scale, i.e., flat lizardite vs. curved chrysotile, and short-range scale, i.e., distortion of polyhedra (Blaha and Rosasco 1978). Considering the almost end-member stoichiometry of both the chrysotile used for this investigation and the lizardite-1T studied by , we tend to associate the observed differences with the contrasting structures of both phases.…”

Section: Raman and Ftir Spectra At Ambient Conditionsmentioning

confidence: 87%

“…Thus, only state-of-the-art ab initio techniques are suited to unravel the exact number of vibrational bands considering the influence of substitution, crystal defects or such physical influences like LO-TO splitting. The two adjacent IR bands at 3695 and 3702 cm -1 are probably caused by a minor substitutional exchange of Mg by Fe (Yariv and Heller-Kallei 1975) or a distortion of the SiO 4 tetrahedra (Blaha and Rosasco 1978). LO-TO splitting as cause for an OH band multiplication in FTIR data can be excluded due to the size of individual chrysotile fibers with respect to the IR wavelength range.…”

Section: Raman and Ftir Spectra At Ambient Conditionsmentioning

confidence: 97%

The dehydroxylation of chrysotile: A combined in situ micro-Raman and micro-FTIR study

Trittschack

Grobéty

2013

American Mineralogist

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One of the most important mechanisms releasing water in subducting slabs of oceanic crust is connected to the dehydration of serpentinized oceanic rocks. This study reports on a detailed investigation of the transition from chrysotile-an important serpentine mineral-to forsterite through the release of water.The dehydroxylation of natural chrysotile and the subsequent phase change to forsterite was studied by in situ micro-Raman and micro-FTIR spectroscopy in the temperature range of 21 to 871 C. Comparisons were made with previously published data of lizardite-1T. Micro-Raman spectra obtained in the low-frequency (100-1200 cm -1 ) and high-frequency ranges (3500-3800 cm -1 ) were complemented by micro-FTIR measurements between 2500 and 4000 cm -1 to study changes in the chrysotile structure as a function of dehydroxylation progress. In general, room-temperature chrysotile bands lie at higher wavenumbers than equivalent bands of lizardite-1T except of three bands positioned at 301.7, 317.5, and 345.2 cm -1 . Different band assignments of chrysotile and lizardite-1T Raman spectra from literature are compared. The most striking assignments concern the three aforementioned Raman bands and those lying between 620 and 635 cm -1 . The present data support a chrysotile-or at least curved TO layer related origin of the latter. Deconvolution of overlapping OH stretching bands at room temperature revealed the presence of five (FTIR) and four (Raman) bands, respectively. A slight change in the ditrigonal distortion angle during heating and the effects of a radius-dependent dehydroxylation progress can be shown. Furthermore, it was possible to identify a quenchable talclike phase immediately after the onset of the dehydroxylation at 459 C. Main bands of this phase are positioned at 184.7, 359.2, and 669.1 cm -1 and a single OH band at 3677 cm -1, and are thus quite similar to those reported for dehydroxylating lizardite-1T. Their appearance coincides with the formation of forsterite. A maximum in the integral intensity of the talc-like intermediate is reached at 716 C. At higher temperatures, the intermediate phase breaks down and supports the accelerated growth of forsterite. The lack of OH bands with the concomitant appearance of broad chrysotile-related modes in the low-frequency range after heating the sample to 871 C indicates the presence of a heavily disordered phase still resembling chrysotile. However, there are no spectral evidences for further Si-and/ or Mg-rich amorphous phases during the dehydroxylation and no indications for a relationship between the breakdown of the talc-like phase and the growth of enstatite as previously reported in literature.

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“…The Raman spectra of amosite,4,5 anthophyllite,5h7 chrysotile,4,5 crocidolite4,5 and tremolite4, 8 Ðbres, have been recorded in the 200È2000 cm~1 wavenumber region. Only tremolite has been studied by comparison with the non-Ðbrous form by Raman spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

“…Only tremolite has been studied by comparison with the non-Ðbrous form by Raman spectroscopy. 8 Lewis et al 4 used the technique to analyse pieces of asbestos waste.…”

Section: Introductionmentioning

confidence: 99%

Asbestos fibre identification by Raman microspectroscopy

Bard

Yarwood

Tylee

1997

J. Raman Spectrosc.

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Raman microspectroscopy has been shown to be a very powerful technique for the identiÐcation and characterization of small mineral Ðbres, with little or no sample preparation. Such spectra are sensitive to the composition of the mineral and can often be used to distinguish between similar species. The technique can be employed for the identiÐcation of single micrometre-sized Ðbres. Vibrational spectra were obtained from Ðve asbestos reference standards for comparison with four non-Ðbrous analogues. The di †erent species such as amosite, anthophyllite, chrysotile, crocidolite and tremolite give distinct spectra. Apparently no important di †erences appear between spectra of asbestos Ðbres and their non-Ðbrous forms, except in the OH-stretching region. For each spectrum, all peaks were listed in order to determine spectral features. The reference spectra were used for the identiÐcation of known and unknown (industrial samples) Ðbres on cellulose acetate Ðlters.

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Raman microprobe spectra of individual microcrystals and fibers of talc, tremolite, and related silicate minerals

Cited by 76 publications

References 14 publications

Structure-Composition Relationships in Trioctahedral Chlorites: A Vibrational Spectroscopy Study

Structure-Composition Relationships in Trioctahedral Chlorites: A Vibrational Spectroscopy Study

The dehydroxylation of chrysotile: A combined in situ micro-Raman and micro-FTIR study

Asbestos fibre identification by Raman microspectroscopy

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