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Clark and others 2007 USGS Data Series 231
Spectral Library splib06a Sample Description

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

TITLE: Black_Mn_Coat_Tailings LV95-3 DESCRIPT

DOCUMENTATION_FORMAT: MIXTURE

SAMPLE_ID: LV95-3

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

MIXTURE: Mn-coating on rock

FORMULA: Not available

FORMULA_HTML: Not available

COLLECTION_LOCALITY: Leadville Mining District, Leadville, Colorado, USA

ORIGINAL_DONOR: Gregg Swayze

CURRENT_SAMPLE_LOCATION: U.S.G.S. Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: U.S.G.S. Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Sample was collected from the distal base of a waste rock pile at about 3400 meter elevation 3 km east of the City of Leadville, Colorado. The surface measured spectrally is that which faced upward.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Not Available

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

The dark surface coating was subjected to SEM Energy Dispersive Spectroscopy compositional analyses. There is definitely Mn present. The larger chunks appear to be MnFe oxides surrounded by gypsum blades. A thin layer of amorphous (?) material coats the larger MnFe oxides. The amorphous material is composed of Mg, Al, Si, S, Ca, and Zn. Mn and Fe are also present in the spectrum for this material but I'm not sure how much is coming from background of the larger MnFe oxide. (Analyist: Heather Lowers)

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

None

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

Spectrum increases monotonically from short wavelengths in the UV to a relative maximum in reflectance near 2.3 microns. Superimposed on this broad absorption that is apparently characteristic of Mn-coatings is a broad band centered at 1.28 microns. A weak band near 2.34 microns may indicate carbonate or chlorite?

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2_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: splib05a r 9062 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib06a r 26691 g.s.=