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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: Nontronite NG-1 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: NG-1.a, NG-1.b

MINERAL_TYPE: Phyllosilicate

MINERAL: Nontronite (Fe-bearing Smectite) (Montmorillonite group)

FORMULA: Na0.33(Fe+3)2(Si,Al)4O10*nH20

FORMULA_HTML: Na0.33Fe+32(Si,Al)4O10•nH2O

COLLECTION_LOCALITY: Holen Hagen, Germany

ORIGINAL_DONOR: Clay Mineral Society

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

A spectrum for this sample was published by:

Clark, R.N., T.V.V. King, M. Klejwa, G. Swayze, and N. Vergo, 1990, High spectral resolution reflectance spectroscopy of minerals: J. Geophys Res. 12653-12680.

who noted that it was spectrally pure.

The spectrum from 2.5-25µm was 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.

Grain size fractions are indicated by the extension after the sample number:
.a = bulk
.b = less than 2µm

IMAGE_OF_SAMPLE:
Photo of sample

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Analysis by Norma Vergo indicates the sample is nontronite + quartz + other; the less than 2µm cut was nontronite + trace quartz.

END_XRD_ANALYSIS.

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


COMPOSITION
KEYWORD
Oxide
ASCII
Amount Weight
Percent, %
Oxide
html
COMPOSITION: SiO2 80.0 wt% SiO2
COMPOSITION: TiO2 0.05 wt% TiO2
COMPOSITION: Al2O3 2.00 wt% Al2O3
COMPOSITION: Fe2O3 11.1 wt% Fe2O3
COMPOSITION: MnO less than 0.02 wt% MnO
COMPOSITION: MgO 0.42 wt% MgO
COMPOSITION: CaO 0.56 wt% CaO
COMPOSITION: Na2O less than 0.15 wt% Na2O
COMPOSITION: K2O 0.72 wt% K2O
COMPOSITION: P2O5 less than 0.05 wt% P2O5
COMPOSITION: LOI 5.28 wt% LOI
COMPOSITION: Total 100.35 wt%
COMPOSITION: O=Cl,F,S wt% #correction for Cl, F, S
COMPOSITION: New Total 100.35 wt%

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

XRF Analysis by Branch of Analytical Chemistry, USGS, Denver.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

50% quartz
1-2% opaques
no HCl fizz.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2c3d4_ # NG-1.a # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1b2b3b4_ # NG-1.b <2um # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns