Sample Description USGS Spectral Library Version 7

USGS Spectral Library Version 7 Sample Description

Kokaly, R.F., Clark, R.N., Swayze, G.A., Livo, K.E., Hoefen, T.M., Pearson, N.C., Wise, R.A., Benzel, W.M., Lowers, H.A., Driscoll, R.L., and Klein, A.J., 2017, USGS Spectral Library Version 7: U.S. Geological Survey Data Series 1035, 61 p., https://doi.org/10.3133/ds1035
_{For more information on the library, see:
local link
web link}

TITLE: K-Alunite CU98-5C Intermd. Temp? DESCRIPT

DOCUMENTATION_FORMAT: MIXTURE

SAMPLE_ID: CU98-5C

MIXTURE_TYPE: Intimate

MIXTURE: K-alunite + other mineral phases

FORMULA: KAl3(SO4)2(OH)6

FORMULA_HTML: KAl₃(SO₄)₂(OH)₆

COLLECTION_LOCALITY: Eastern Alteration Center, Cuprite, Nevada, USA

ORIGINAL_DONOR: Gregg Swayze

COLLECTION_LATITUDE: N37 32.087' # degrees and decimal minutes (N or S)

COLLECTION_LONGITUDE: W117 10.193' # 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 was collected from the southeastern portion of the eastern alteration center at Cuprite, NV. The sample was a volcanic rhyolite tuff of Tertiary age prior to hydrothermal alteration about 7.6 Ma.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

alunite (major), opal-A (major), tridymite (minor), and quartz (trace).

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: XRF # XRF, EPMA, ICP(Trace), WChem

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

None

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

The spectrum has absorptions characteristic of alunite. The relatively less intense absorption features may indicate that this alunite formed at intermediate temperatures (less than that of alunite CU91-217G1).

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history of the Cuprite Mining District, southwestern Nevada: an integrated geological and geophysical approach: unpublished Ph.D. Dissertation, University of Colorado at Boulder, 399p.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: 1b2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns