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: Illite CU00-5B Hi-Al+Quartz DESCRIPT

DOCUMENTATION_FORMAT: MIXTURE

SAMPLE_ID: CU00-5B

MIXTURE_TYPE: Intimate

MIXTURE: Illite + quartz

FORMULA: Al2Si2O5(OH)4 + SiO2

FORMULA_HTML: (K,H₃O)(Al,Mg,Fe)₂(Si,Al)₄O₁₀[(O H)₂,H₂O] + SiO₂

COLLECTION_LOCALITY: Western Alteration Center, Cuprite, Nevada, USA

ORIGINAL_DONOR: Gregg Swayze

COLLECTION_LATITUDE: N37 31.65' # degrees and decimal minutes (N or S)

COLLECTION_LONGITUDE: W117 13.18' # degrees and decimal minutes (W or E)

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 southern part of the western alteration center at Cuprite, NV. The sample was collected from the altered lower Cambrian Harkless Phyllite that was hydrothermally altered about 7.5 Ma. The collection site is within 100 meters of a quartz latite instrusive sill which probably elevated the temperature of country rocks in this area.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Quartz (major), illite (both 1M and 2M2 polytypes).

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:

The spectrum has band characteristic of Al-rich illite or muscovite. Spectrally differentiating illite from muscovite cannot be done at this spectral resolution and perhaps not at any spectral resolution. The 1st overtone of the OH stretch is at 1.4084 microns and the Al-OH combination band is located at 2.1966 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history of the Cuprite Mining District, southwestern Nevada: an integrated geological and geophysical approach: unpublished Ph.D. Dissertation, University of Colorado at Boulder, 399p.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 8360	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib06a r 25438			g.s.=