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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: Hematite HS45 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS45

MINERAL_TYPE: Oxide

MINERAL: Hematite (Hematite group)

FORMULA: alpha-Fe2O3

FORMULA_HTML: alpha-Fe2O3

COLLECTION_LOCALITY: Ironton, MN

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Dimorphous with Maghemite.

The spectrum of this sample was originally published in:

Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1971, Visible and near-infrared spectra of minerals and rocks: III. Oxides and hydroxides. Modern Geology, v. 2, p. 195-205.

With the note that "this sample departs considerably from a pure stoichiometric single crystal, but is typical of naturally occurring hematite."

The sample measured for the library was HS45.3 which was dry sieved to the grain size interval 74-250µm.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 7.3-9.5 keV
File: hemat45.mdi, *.out (smear mount on quartz plate)
References: Huebner's reference patterns
Found: Hematite; traces of quartz and a 7 angstrom phase

Comment: Strong, narrow, symmetric hematite reflections indicate excellent crystallinity and suggest compositional heterogeneity. Hematite peak positions are consistent with Fe2O3 composition. The quartz identification is based upon two very weak (and broad) reflections. Very weak reflections at 7.2 and 3.55 angstroms indicate the presence of a 7 or 14 angstroms phase (possibly chlorite).

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

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

None.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2_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 2113 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 3273 0.2-3.0µm 200 g.s.=


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