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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: Albite GDS30 Plagioclase DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: GDS30 and NMNH C5390

MINERAL_TYPE: Tectosilicate

MINERAL: Albite (Plagioclase, Na end member)(Feldspar group)

FORMULA: NaAlSi3O8

FORMULA_HTML: NaAlSi3O8

COLLECTION_LOCALITY: Rutherford, VA

ORIGINAL_DONOR: Jack Salisbury

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Spectra from 2.5 to 25 µm for this sample are published 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.

"Sample is translucent and light gray to white in color. This is the classic Amelia albite. Hand specimen is large (2 cm) fragment of twinned crystal. Appears very fresh. Is translucent and light gray to white in color."

Sample measured for the library is the 74-250µm interval.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Pure albite.

END_XRD_ANALYSIS.

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


COMPOSITION
KEYWORD
Oxide
ASCII
Amount Weight
Percent, %
Oxide
html
COMPOSITION: SiO2 68.18 wt% SiO2
COMPOSITION: TiO2 0.01 wt% TiO2
COMPOSITION: Al2O3 20.07 wt% Al2O3
COMPOSITION: FeO 0.01 wt% FeO
COMPOSITION: MnO 0.01 wt% MnO
COMPOSITION: MgO 0.02 wt% MgO
COMPOSITION: CaO 0.02 wt% CaO
COMPOSITION: Na2O 10.37 wt% Na2O
COMPOSITION: K2O 0.20 wt% K2O
COMPOSITION: Total 99.88 wt%
COMPOSITION: O=Cl,F,S wt% #correction for Cl, F, S
COMPOSITION: New Total wt%

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

"Flame photometry and atomic absorption analysis of samples from the same location (not the same sample) show 98.42 mole percent albite. Microprobe analysis shows sample to be homogeneous within and between grains. Ten analyses indicate pure albite end member compostion."

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

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

avg. grain size = 190µm

Clear tabular grains, mostly cleavage bound grains. 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 95 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 144 0.2-3.0µm 200 g.s.= 190 µm


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