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(For further information on spectroscopy, see:
http://speclab.cr.usgs.gov)
TITLE: Jarosite on Alt. Rhyolite CU91-20A DESCRIPT
DOCUMENTATION_FORMAT: MIXTURE
SAMPLE_ID: CU91-20A
MIXTURE_TYPE: Intimate
MIXTURE: Jarosite on altered rhyolite
FORMULA: KFe3(SO4)2(OH)6
FORMULA_HTML: KFe3+3(SO4)2(OH)6
COLLECTION_LOCALITY: Eastern Alteration Center, Cuprite, Nevada, USA
ORIGINAL_DONOR: Gregg Swayze
COLLECTION_LATITUDE: N37 33.20' # degrees and decimal minutes (N or S)
COLLECTION_LONGITUDE: W117 10.55' # degrees and decimal minutes (W or E) P> DATUM: NAD27 # coordinate datum
CURRENT_SAMPLE_LOCATION: U.S.G.S. Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: U.S.G.S. Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
This sample is of a jarosite coating on a hydrothermally altered rhyolite. The sample was collected from the relict eastern hydrothermal center which was active about 7.6 Ma. Sample was collected from the northern portion of the eastern center.
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
Jarosite coating XRD: K-jarosite.
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: XRF # XRF, EM(WDS), ICP(Trace), WChem
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION:
None
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
None
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
Spectrum has absorptions characteristic of jarosite with a narrow 0.4367 micron band and broader 0.9129 micron band. There is a vibrational absorption also characteristic of jarosite at 2.2687 microns.
See: Swayze, G.A., 1997, The hydrothermal and structural history of the Cuprite Mining District, southwestern Nevada: an integrated geological and geophysical approach: unpublished Ph.D. Dissertation, University of Colorado at Boulder, 399p.
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: | splib05a r 8381 | 0.2-3.0µm | 200 | g.s.= |
| LIB_SPECTRA: | splib06a r 25459 | g.s.= |