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DOCUMENTATION_FORMAT: MIXTURE
SAMPLE_ID: LV95-3
MIXTURE_TYPE: Coating
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, EPMA, 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