Spectroscopy Lab

Multimedia

Filter Total Items: 39
 Expanded vermiculite ores examined in this study: their sources and amphibole, talc, and/or serpentine impurities.
February 13, 2019

Expanded vermiculite ores examined in this study

Table 1.  Expanded vermiculite ores examined in this study: their sources and amphibole, talc, and/or serpentine impurities.

Notes: XRD = X-ray diffraction analysis of bulk ore samples (B) and sink fractions (S).  SEM-EDS = Scanning Electron Microscope – Energy-Dispersive X-Ray Spectroscopy.  Band Depth Ratio = 1.40/1.42-µm band depth ratio.  The use of "sodic-

...
Average EPMA chemical analyses and calculated mineral formulas of selected unexpanded vermiculite ores.
February 13, 2019

Average EPMA chemical analyses and calculated mineral formulas.

Table 2.   Average EPMA chemical analyses and calculated mineral formulas of selected unexpanded vermiculite ores.

Notes: Compositions of bulk samples not individual minerals.  n = number of microprobe spot analyses collected on multiple mica flakes used to calculate the averaged composition of each sample.   ---- = not enough cation Al and/or Mg to assign to this

...
Summary of OH-related mid-infrared (MIR) spectral features of unexpanded and expanded vermiculite ores.
February 13, 2019

Summary of OH-related mid-infrared (MIR) spectral features.

Table 5.  Summary of OH-related mid-infrared (MIR) spectral features of unexpanded and expanded vermiculite ores.

Notes: Vibrational positions from spectra of handpicked, ground mica flakes from the unexpanded GDS469 ore sample from Libby, MT; the unexpanded ALB5SA00 ore sample from Palabora, S. Africa; and the expanded vermiculite ores as noted.  Vibrational

...
Summary of OH-related near-infrared spectral features of unexpanded and expanded vermiculite ores.
February 13, 2019

Summary of OH-related near-infrared spectral features.

Table 6.  Summary of OH-related near-infrared spectral features of unexpanded and expanded vermiculite ores.

Notes: Vibrational positions from spectra of handpicked, ground mica flakes from the unexpanded GDS469 ore sample from Libby, MT; and the expanded vermiculite ores as noted.  Vibrational assignments from this study.  oa = OH overtone;

...
Electron probe microanalysis analyses and resulting formula of an unexpanded VTx-1 Mg-vermiculite sample from Llano, Texas.
February 13, 2019

Electron probe microanalysis analyses and resulting formula.

Table A5.  Electron probe microanalysis analyses and resulting formula of an unexpanded VTx-1 Mg-vermiculite sample from Llano, Texas. 

Notes:

a Microprobe data for all Fe are binned into FeO.

b There are no data on H2O content. 

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 expanded vermiculite ore.

Figure 16. Average 1.40/1.42 – 1.38/2.32-μm band-depth-ratio values of commercial expanded vermiculite ore samples used to determine their mine sources.

Mine sources of expanded vermiculite ore samples.
November 6, 2017

Mine sources of expanded vermiculite ore samples

Figure A15. Same as Figure 21 with 2.24/2.38-μm band depth ratio and 2.24-μm absorption wavelength position 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).

Mine sources of expanded vermiculite ore samples based on their average 2.24/2.38 – 1.38/2.32-μm band-depth-ratio values.
November 6, 2017

Mine sources of expanded vermiculite ore samples.

Figure 18. Mine sources of expanded vermiculite ore samples based on their average 2.24/2.38 – 1.38/2.32-μm band-depth-ratio values.

Comparison of the unexpanded Libby ore in transmission and reflectance.
November 6, 2017

Comparison of the unexpanded Libby ore in transmission and reflectance

Figure 19. Comparison of the continuum-removed OH-stretch-overtone region of handpicked, ground flakes of hydrobiotite from the unexpanded Libby ore in transmission and reflectance.

Figure 1. Photographs of commercial, expanded vermiculite ore from the four major historical sources.
November 6, 2017

Photographs of commercial, expanded vermiculite ore.

Figure 1. Photographs of commercial, expanded vermiculite ore from the four major historical sources: Libby, Montana; Palabora, South Africa; Louisa, Virginia; and Enoree, South Carolina. Scale of the rightmost image in each set is the same as the left image unless otherwise labeled. Note (k) shows Libby vermiculite insulation with admixed cellulose whereas (l) shows

...
Continuum-removed absorbance spectra.
November 6, 2017

Continuum-removed absorbance spectra.

Figure 20. (a) Continuum-removed absorbance spectra of the NIR combination region for unexpanded and expanded vermiculite ore samples from Enoree, South Carolina (same samples as used in Fig. 19), with their deconvolution into symmetrical Gaussians. (b) Continuum-removed reflectance spectra of the same samples in the same spectral region. Both sample containers were

...
Mine sources of expanded vermiculite ore samples.
November 6, 2017

Mine sources of expanded vermiculite ore samples.

Figure 21. Mine sources of expanded vermiculite ore samples based on the average 2.24/2.38-μm band-depth-ratio values and 2.24-μm composite absorption wavelength positions in microns.