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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
For more information on the library, see: local link web link

TITLE: Alunite GDS95 Na Syn (150C) DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: GDS95

MINERAL_TYPE: Sulfate

MINERAL: Na-Alunite

FORMULA: NaAl3(SO4)2(OH)6

FORMULA_HTML: NaAl3(SO4)2(OH)6

COLLECTION_LOCALITY: Not available

ORIGINAL_DONOR: Roger Stroffregen

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Synthetically prepared pure Na-endmember sample made at 150C. Sample is 100% mole fraction Na.

See Stroffregen, R.E., and C.N. Alpers, Observations on the unit-cell dimensions, H2O contents, and delD values of natural and synthetic alunite, American Mineralogist, 77, 1092-1098, 1992.

IMAGE_OF_SAMPLE:
Photo of sample

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

see: Stroffregen, R.E., and C.N. Alpers, Observations on the unit-cell dimensions, H2O contents, and delD values of natural and synthetic alunite, American Mineralogist, 77, 1092-1098, 1992.

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: NONE # XRF, EPMA, ICP(Trace),WChem

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

Sample has relatively weak vibrational features between 1.4 - 1.5, 1.76,and 2.17 microns. Other pure Na-endmember alunites prepared at higher temperatures have much stronger vibrational features.

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1_2a3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns