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Clark et. al. 2003 USGS Open File Report 03-395
Spectral Library splib05a Sample Description

(For further information on spectrsocopy, see: http://speclab.cr.usgs.gov)

TITLE: Halite HS433 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS433

MINERAL_TYPE: Halide

MINERAL: Halite

FORMULA: NaCl

FORMULA_HTML: NaCl

COLLECTION_LOCALITY: Kansas

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

"H-4. Halite. Kansas (433B). Halite, NaCl, occurs primarily as extensive beds formed by evaporation of trapped bodies of salt water. It may also form as an efflorescence on the surface in arid areas, or as a sublimation product in volcanic regions. It is colorless when pure, but more typically orange or red, and may be gray, yellow or blue. The common orange or red color is due to inclusions of ferric oxide material, while the gray is due to inclusions of clay. Like many of the halides, halite is subject to color center formation, which is responsible for the blue and purple tints. This sample is colorless and appears to be quite pure. It displays some very weak water bands from water in fluid inclusions near 1.95 and 2.25 µ, but is otherwise spectrally featureless, except for the 0-5 µ particle size range. The distinct brownish tone of this size range is caused by polyurethane contamination from the fluid energy mill."

Sieve interval 74 - 250µm.

Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1972, Visible and near-infrared spectra of minerals and rocks: V. Halides, phosphates, arsenates, vanadates and borates. Modern Geology, v. 3, p. 121-132.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 6.5-9.5 keV
File: halt433.mdi, *.out (smear mount on quartz plate)
References: JCPDS #5-628; Huebner's internal standard listings
Found: Halite

Comment: Reflections symmetrical but not sharp and the alpha1-alpha2 splitting is not distinct; the degree of crystallization is only moderate. Lattice spacing's are consistent with NaCl composition (and inconsistent with (Na,K)Cl solid solution.

J.S. Huebner, J. Pickrell, and T. Schaefer, 1994, written communication.

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem

COMPOSITION_TRACE:

None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

average grain size= 230 µm

Grains isotropic with cubic cleavage. Grains also have abundant (8 vol%) fluid or gas inclusions, and the grains are soluble in water. All this is consistent with this sample being pure salt.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1a2_3_4_ # 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 1910 0.2-3.0µm 200 g.s.= 230 µm
LIB_SPECTRA: splib05a r 3015 0.2-3.0µm 200 g.s.=


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