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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: Labradorite HS17 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS17

MINERAL_TYPE: Tectosilicate

MINERAL: Labradorite (Plagioclase)(Feldspar group)

FORMULA: (NaAlSi,CaAl2)Si2O8

FORMULA_HTML: (NaAlSi,CaAl2)Si2O8

COLLECTION_LOCALITY: Ontario

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

"T-10 Labradorite 17B--Ontario. This plagioclase feldspar is composed of 30 to 50% albite. The spectrum of this sample is relatively flat and has a low reflectivity caused by the presence of magnetite as a microscopic disseminated impurity. We cannot account specifically for the maximum in reflectivity near 1.0µ in this spectrum. It is due to exceptionally broad, very weak absorptions on either side."

Sieve interval 74 - 250µm.

Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1973, Visible and near-infrared spectra of minerals and rocks: VI. Additional silicates. Modern Geology, v. 4, p. 85-106.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Labradorite + 6.25, 6.34 Angstroms (small amount) (Norma Vergo, USGS)

END_XRD_ANALYSIS.

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

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Not done yet

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 2696 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 4064 0.2-3.0µm 200 g.s.=


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