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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: Anorthite GDS28 Plagioclase DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: GDS28

MINERAL_TYPE: Tectosilicate

MINERAL: Anorthite (Plagioclase, Ca end member)(Feldspar group)

FORMULA: CaAl2Si2O8

FORMULA_HTML: CaAl2Si2O8

COLLECTION_LOCALITY: Synthetic

ORIGINAL_DONOR: Bruce Hemingway, U.S.G.S.

CURRENT_SAMPLE_LOCATION: USGS Reston, VA.

ULTIMATE_SAMPLE_LOCATION: USGS Reston, VA.

SAMPLE_DESCRIPTION:

The original sample and mid-IR spectrum was described in:

Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263.

From that study, the sample was described as pure.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Pure Anorthite.

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: EM(WDS) # XRF, EM(WDS), ICP(Trace), WChem


COMPOSITION
KEYWORD
Oxide
ASCII
Amount Weight
Percent, %
Oxide
html
COMPOSITION: SiO2 43.53 wt% SiO2
COMPOSITION: TiO2 0.01 wt% TiO2
COMPOSITION: Al2O3 37.36 wt% Al2O3
COMPOSITION: FeO 0.02 wt% FeO
COMPOSITION: MnO 0.03 wt% MnO
COMPOSITION: MgO 0.03 wt% MgO
COMPOSITION: CaO 19.26 wt% CaO
COMPOSITION: Na2O 0.03 wt% Na2O
COMPOSITION: K2O 0.04 wt% K2O
COMPOSITION: Total 100.32 wt%
COMPOSITION: O=Cl,F,S wt% #correction for Cl, F, S
COMPOSITION: New Total 100.32 wt%

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

Microprobe analysis is the average of 10 analyses. See also: Robie, R.A., Hemingway, B.S., and Wilson, W.H., 1978, American Min., v.63, p. 9-123.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

The sample appears to be pure anorthite with very fine (cryptocrystalline) texture according to:

Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263. avg. grain size = 200um

Abundant vapor bubbles or fluid inclusions, elongate grains sometimes sided by cleavage planes. G. Swayze

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 457 0.2-3.0µm 200 g.s.= 125µm
LIB_SPECTRA: splib05a r 1075 0.2-3.0µm 200 g.s.=


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