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: Microcline+others HS107 DESCRIPT

DOCUMENTATION_FORMAT: MIXTURE

SAMPLE_ID: HS107.3B

MIXTURE_TYPE: Intimate

MIXTURE: Microcline + albite(minor) + muscovite(minor)

FORMULA: KAlSi3O8 + NaAlSi3O8 + KAl2(Si3Al)O10(OH,F)2

FORMULA_HTML: KAlSi₃O₈ + NaAlSi₃O₈ + KAl₂(Si₃Al)O₁₀(OH,F)₂

COLLECTION_LOCALITY: Keystone, South Dakota

ORIGINAL_DONOR: Hunt and Salisbury Collection

COLLECTION_LATITUDE: Not Available # degrees and decimal minutes (N or S)

COLLECTION_LONGITUDE: Not Available # degrees and decimal minutes (W or E)

DATUM: Not Available # coordinate datum

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Natural intimate mixture of microcline with lesser amounts of albite and muscovite.

"The spectrum (107B) displays a very intense OH band near 1.4µ with an accompanying feature near 2.2µ. The very weak band near 1.9µ indicates only a very small amount of H₂O. The bands are consistent with the incipient alteration of this sample to kaolinite."

Sieve interval 74 - 250µm.

Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1973, Visible and near-infrared spectra of minerals and rocks: VI. Additional silicates. Modern Geology, v. 4, p. 85-106.

Note, however, that the 2.2-2.4 µm bands are those of muscovite (or similar mica), not kaolinite as noted by Hunt and others.

That is confirmed by XRD below. R. Clark

IMAGE_OF_SAMPLE:

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Microcline + albite(minor) + muscovite(minor)

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1a2a3a4a # HS107.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns