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(For further information on spectroscopy, see:
http://speclab.cr.usgs.gov)
TITLE: Thenardite GDS146 DESCRIPT
DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: GDS146
MINERAL_TYPE: Sulfate
MINERAL: Thenardite
FORMULA: Na2SO4
FORMULA_HTML: Na2SO4
COLLECTION_LOCALITY: Saline Valley, California
ORIGINAL_DONOR: Jim Crowley
CURRENT_SAMPLE_LOCATION: USGS Reston, Virginia
ULTIMATE_SAMPLE_LOCATION: USGS Reston, Virginia
SAMPLE_DESCRIPTION:
Spectrum originally published in: Crowley, J.K., 1991, Visible and Near-Infrared (0.4 - 2.5µm) Reflectance Spectra of Playa Evaporite Minerals: Journal of Geophysical Research, vol 96, no.B10, p. 16,231-16,240.
IMAGE_OF_SAMPLE:
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
40 kV - 30 mA, 6.5-9.5 keV
File: tnrdt146.out, -.mdi
References: JCPDS #37-1465, HS450.3B
Found: Thenardite, weak to very weak unidentified reflections at
3.57, 2.00, and 1.78 Angstroms.
Comment: Well-crystallized phase, but not as well crystallized
(pattern not as sharp) as HS450.3B
J.S. Huebner, J. Pickrell, T. Schaefer, written communication(USGS)
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem
COMPOSITION_TRACE:
COMPOSITION_DISCUSSION:
Presence of features at 1.5 and 2.1 µm indicates the contamination of this sample. Ideally thenardite Na2SO4 should be anhydrous. The spectral features at these positions may be due to different mineral phases or partial hydration of this sample. G. Swayze.
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1c2c3c4? # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
| LIB_SPECTRA_HED: | where | Wave Range | Av_Rs_Pwr | Comment |
|---|---|---|---|---|
| LIB_SPECTRA: | splib04a r 4739 | 0.2-3.0µm | 200 | g.s.= |
| LIB_SPECTRA: | splib05a r 6521 | 0.2-3.0µm | 200 | g.s.= |
| LIB_SPECTRA: | splib06a r 21682 | g.s.= | ||
| LIB_SPECTRA: | splib06a r 21694 | g.s.= |