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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: Alun0.3+Musc0.4+Pyro0.3 AMX1 DESCRIPT

DOCUMENTATION_FORMAT: MIXTURE

SAMPLE_ID: AMX1

MIXTURE_TYPE: Areal

MIXTURE: Alun. 30% + Musc 40% +Pyroph 30%

FORMULA: KAl3(SO4)2(OH)6 + KAl2[AlSi3O10](OH,F)2 + Al2Si4O10(OH)2

FORMULA_HTML: KAl3(SO4)2(OH)6 + KAl2[AlSi3O10](OH,F)2 +
Al2Si4O10(OH)2

COLLECTION_LOCALITY: Constructed from other spectra

ORIGINAL_DONOR: Gregg Swayze

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

See alunite_res9, muscovite_gds113, pyrophyllite_pys1a.html

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

See alunite_res9, muscovite_gds113, pyrophyllite_pys1a.html

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE:

See alunite_res9, muscovite_gds113, pyrophyllite_pys1a.html

COMPOSITION_DISCUSSION:

See alunite_res9, muscovite_gds113, pyrophyllite_pys1a.html

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

See alunite_res9, muscovite_gds113, pyrophyllite_pys1a.html

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

See alunite.res9, muscovite.gds113, pyrophyllite.pys1a.html

END_SPECTROSCOPIC_DISCUSSION.

Spectrum has very complex 1.4 and 2-2.5 micron region with superimposed absorptions from all three minerals. The 2.17 micron band typical of alunite has a sharp 2.165 micron band from pyrophyllite. Spectral features of muscovite in this region and at 1.4 microns are dominated by those of alunite and pyrophyllite.

SPECTRAL_PURITY: 1a2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns