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USGS Spectral Library Version 7 Sample Description

Kokaly, R.F., Clark, R.N., Swayze, G.A., Livo, K.E., Hoefen, T.M., Pearson, N.C., Wise, R.A., Benzel, W.M., Lowers, H.A., Driscoll, R.L., and Klein, A.J., 2017, USGS Spectral Library Version 7: U.S. Geological Survey Data Series 1035, 61 p., https://doi.org/10.3133/ds1035
For more information on the library, see: local link web link

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:
Photo 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, EPMA, 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: 1c2c3c4u # GDS146 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns