Spectroscopy Lab

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Comparison of vermiculite insulation’s spectral features with those of elongate amphibole.
November 6, 2017

Comparison of vermiculite insulation’s spectral features

Figure 8. Comparison of vermiculite insulation’s spectral features with those of elongate amphibole from Libby, talc (from Clark et al., 2007), and serpentine (chrysotile).

NIR reflectance spectra of the unexpanded Mg-vermiculite.
November 6, 2017

NIR reflectance spectra of the unexpanded Mg-vermiculite.

Figure A7. (a) NIR reflectance spectra of the unexpanded Mg-vermiculite VTx-1 sample from Llano, Texas, before and after K+ exchange.

Reflectance spectra of representative expanded vermiculite ore samples from each of the four major historical sources.
November 6, 2017

Reflectance spectra of representative expanded vermiculite ore samples

Figure 9. Reflectance spectra of representative expanded vermiculite ore samples from each of the four major historical sources.

Continuum-removed (a) OH stretch overtone and (b) combination absorptions of the Mg-vermiculite.
November 6, 2017

Continuum-removed absorptions of Mg-vermiculite.

Figure A8. Continuum-removed (a) OH stretch overtone and (b) combination absorptions of the Mg-vermiculite VTx-1 sample from Llano, Texas, before and after partial deuteration.

Continuum-removed OH stretch overtone and combination absorptions from spectra.
November 6, 2017

Continuum-removed OH stretch overtone and combination absorptions

Figure 10. (a) and (b) show continuum-removed OH stretch overtone and combination absorptions from spectra of handpicked, ground flakes of phlogopite, hydrobiotite, and vermiculite from unexpanded Libby vermiculite ore.

Distribution of individual 1.40/1.42-μm band-depth-ratio values of expanded Libby vermiculite ore.
November 6, 2017

Distribution of band-depth-ratio values of expanded vermiculite ore.

Figure A9. The distribution of individual 1.40/1.42-μm band-depth-ratio values of expanded Libby vermiculite ore is positively skewed by the presence of coarse-grained elongate amphibole bundle impurities.

Evaluation of the total surface area of an expanded vermiculite ore sample.
November 6, 2017

Evaluation of the total surface area of expanded vermiculite ore.

Figure A10. Evaluation of the total surface area of an expanded vermiculite ore sample that must be spectrally measured to derive a precise average 1.38/2.32-μm band-depth-ratio value for source determination.

Continuum-removed absorbance spectra of handpicked, ground flakes of phlogopite, hydrobiotite, and vermiculite.
November 6, 2017

Continuum-removed absorbance spectra.

Figure 11. Continuum-removed absorbance spectra of handpicked, ground flakes of phlogopite, hydrobiotite, and vermiculite from unexpanded Libby ore, and of a K+-exchanged split of the vermiculite, showing the OH stretch fundamental absorptions and their deconvolution into symmetrical Gaussians.

Evaluation of the total surface area of an expanded vermiculite ore sample.
November 6, 2017

Evaluation of the total surface area of expanded vermiculite ore.

Figure A12. Evaluation of the total surface area of an expanded vermiculite ore sample that must be spectrally measured to derive a precise average 2.24/2.38-μm band-depth-ratio value for source determination.

Continuum-removed absorbance spectra of handpicked, ground phlogopite, hydrobiotite, and vermiculite flakes.
November 6, 2017

Continuum-removed absorbance spectra.

Figure 12. Continuum-removed absorbance spectra of handpicked, ground phlogopite, hydrobiotite, and vermiculite flakes from unexpanded Libby ore showing the out-of-plane and in-plane cation-OH bend fundamental absorptions and their deconvolution into symmetrical Gaussians.

Average 1.40/1.42 – 1.38/2.32-μm band-depth-ratio values of commercial expanded vermiculite ore samples.
November 6, 2017

Average band-depth-ratio values of commercial vermiculite ore.

Figure A13. Same as Figure 16 with band-depth-ratio values of a few expanded vermiculite ore samples derived from spectra measured at finer spectral resolution (6 nm) then convolved to the sampling and bandpasses of the normal resolution (11 nm).

Continuum-removed absorbance spectra of handpicked, ground phlogopite, hydrobiotite, and vermiculite flakes.
November 6, 2017

Continuum-removed absorbance spectra

Figure 13. Continuum-removed absorbance spectra of handpicked, ground phlogopite, hydrobiotite, and vermiculite flakes from unexpanded Libby ore showing the OH-stretch overtone absorptions and their deconvolution into symmetrical Gaussians.