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Clark et. al. 2003 USGS Open File Report 03-395
Spectral Library splib05a Sample Description

(For further information on spectrsocopy, see: http://speclab.cr.usgs.gov)

TITLE: Desert_Varnish GDS78A DESCRIPT

DOCUMENTATION_FORMAT: MIXTURE

SAMPLE_ID: GDS78A

MIXTURE_TYPE: Coating # Areal, Intimate, Coating, or Molecular

MIXTURE: Desert_Varnish

FORMULA: Na4Mn14O27*9H20 + alpha-Fe2O3 + clays

FORMULA_HTML: Na4Mn14O27•9H2 + alpha -Fe2O3

COLLECTION_LOCALITY: Stoddard Wells, CA.

ORIGINAL_DONOR: George Rossman, California Inst. of Techology

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

"Desert varnish invariably consists of birnessite in intimate mixture with hematite and large amounts of clay minerals. The clays are generally of the illite-montmorillonite type with minor kaolinite, but in several samples this concentration ratio is reversed."

This sample is a coating on desert pavement rhyolite and quartz cobbles.

Potter, R.M. and G.R. Rossman, 1979, Mineralogy of manganese dendrites and coatings. American Mineralogist, v.64, pp 1219-1226.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: # XRF, EM(WDS), ICP(Trace), WChem


COMPOSITION
KEYWORD
Oxide
ASCII
Amount Weight
Percent, %
Oxide
html
COMPOSITION: SiO2 34.35 wt% SiO2
COMPOSITION: TiO2 0.78 wt% TiO2
COMPOSITION: Al2O3 20.01 wt% Al2O3
COMPOSITION: FeO 10.96 wt% FeO
COMPOSITION: MnO 22.63 wt% MnO
COMPOSITION: MgO 2.43 wt% MgO
COMPOSITION: BaO 1.22 wt% BaO
COMPOSITION: CaO 1.28 wt% CaO
COMPOSITION: Na2O 0.23 wt% Na2O
COMPOSITION: K2O 1.89 wt% K2O
COMPOSITION: P2O5 1.10 wt% P2O5
COMPOSITION: Total 96.88 wt%
COMPOSITION: O=Cl,F,S wt% #correction for Cl, F, S
COMPOSITION: New Total wt%

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

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

LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment
LIB_SPECTRA: splib04a r 1365 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 9102 0.2-3.0µm 200 g.s.=


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