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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: 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history of the Cuprite Mining District, southwestern Nevada: an integrated geological and geophysical approach: unpublished Ph.D. Dissertation, University of Colorado at Boulder, 399p.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.=


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