Sample Description USGS Spectral Library Version 7

USGS Spectral Library Version 7 Sample Description

Kokaly, R.F., Clark, R.N., Swayze, G.A., Livo, K.E., Hoefen, T.M., Pearson, N.C., Wise, R.A., Benzel, W.M., Lowers, H.A., Driscoll, R.L., and Klein, A.J., 2017, USGS Spectral Library Version 7: U.S. Geological Survey Data Series 1035, 61 p., https://doi.org/10.3133/ds1035
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TITLE: Sanidine+albite NMNH103200 DESCRIPT

DOCUMENTATION_FORMAT: MIXTURE

SAMPLE_ID: NMNH103200

MIXTURE_TYPE: Intimate

MIXTURE: Sanidine and albite (Feldspar group)

FORMULA: (K,Na)AlSi3O8 and NaAlSi3O8

FORMULA_HTML: (K,Na)AlSi₃O₈ and NaAlSi₃O₈

COLLECTION_LOCALITY: Higasinuiro-gun, Taiji, Wakayama, Japan

ORIGINAL_DONOR: Smithsonian Institution

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

"Result of petrographic examination: Many small (0.5cm) euhedral crystals totaling 6.49 g. almost all have some adhering clay/limonite, to be removed by brushing or ultrasonic cleaning. Under the microscope, a very, very few acicular inclusions (rutile?) can be seen. Otherwise, very pure."

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.

IMAGE_OF_SAMPLE:

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Sanidine plus a moderate amount of albite.

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.

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: EPMA # XRF, EPMA, ICP(Trace), WChem

COMPOSITION
KEYWORD Oxide
ASCII Amount Weight
Percent, % Oxide
html

COMPOSITION: SiO2 67.43 wt% SiO₂

COMPOSITION: TiO2 0.03 wt% TiO₂

COMPOSITION: Al2O3 18.65 wt% Al₂O₃

COMPOSITION: FeO 0.59 wt% FeO

COMPOSITION: MnO 0.02 wt% MnO

COMPOSITION: MgO 0.03 wt% MgO

COMPOSITION: CaO 0.02 wt% CaO

COMPOSITION: Na2O 5.38 wt% Na₂O

COMPOSITION: K2O 7.38 wt% K₂O

COMPOSITION: Total 99.97 wt%

COMPOSITION KEYWORD	Oxide ASCII	Amount	Weight Percent, %	Oxide html
COMPOSITION:	SiO2	67.43	wt%	SiO₂
COMPOSITION:	TiO2	0.03	wt%	TiO₂
COMPOSITION:	Al2O3	18.65	wt%	Al₂O₃
COMPOSITION:	FeO	0.59	wt%	FeO
COMPOSITION:	MnO	0.02	wt%	MnO
COMPOSITION:	MgO	0.03	wt%	MgO
COMPOSITION:	CaO	0.02	wt%	CaO
COMPOSITION:	Na2O	5.38	wt%	Na₂O
COMPOSITION:	K2O	7.38	wt%	K₂O
COMPOSITION:	Total	99.97	wt%

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

"Microprobe analysis shows homogeneity within and between grains. This is typical sanidine with about as much soda as potash, but the albite present is cryptoperthic. Average of 10 analyses."

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.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

A sharp weak absorption at 0.38 microns and broader weak absorption at 0.97 microns indicate the presence of trace levels of contaminants in this sample. G. Swayze.

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1c2b3b4_ # SAMPLE_ID: NMNH103200 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns