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: Kalun+kaol+gth mv2-ar3 DESCRIPT

DOCUMENTATION_FORMAT: MIXTURE

SAMPLE_ID: MV2-AR3

MIXTURE_TYPE: Intimate

MIXTURE: Alunite + kaolinite + goethite

FORMULA: KAl3(SO4)2(OH)6 + Al2Si4O10(OH)2 + Fe3O(OH)

FORMULA_HTML: KAl₃(SO₄)₂(OH)₆ +Al₂ Si₄O₁₀(OH)₂ + Fe₃O(OH)

COLLECTION_LOCALITY: Alunite Ridge, near Christmas Mine, Tushar Mountains, Piute County, Utah LAT/LONG: 38º 22’ 46.05” N, 112º 19’ 48.92” W

ORIGINAL_DONOR: Barnaby Rockwell

CURRENT_SAMPLE_LOCATION: U.S.G.S. Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: U.S.G.S. Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Hydrothermally altered wall rock immediately adjacent to K alunite veins formed in high temperature magmatic steam environment. Dark reddish argillized appearance.

See: Rockwell, B.W.,2002, Descriptions, spectral plots, and digital reflectance spectra of samples applied to spectral analysis of imaging spectroscopy data: Utah (East Tintic Mountains, Oquirrh Mountains, Wasatch Mountains, and Tushar Mountains), Nevada (Goldfield Hills), and New Mexico (Jemez Mountains), USA, 1999-2002: U.S. Geological Survey Open-File Report 02-407, electronic web pages. (http://pubs.usgs.gov/of/2002/ofr-02-407) END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Major greater than 25%: K alunite Minor 5%-25%: kaolinite Trace less than 5%: quartz, goethite, hematite

see:

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: NONE # XRF, EM(WDS), ICP(Trace), WChem

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

None

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

Spectrum mostly dominated by goethite absorptions in the electronic region (.35-1.35 microns) and alunite in the vibrational region (1.35 2.5 microns). A kaolinite absorption forms a shoulder on short wavelength side of the alunite OH overtone doublet in the 1.4 micron region. Kaolinite absorptions also deepen the 2.17 micron absorption increasing the depth of the 2.201 micron alunite band relative to the main alunite band at 2.17 microns.

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2_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 8396	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib06a r 25474			g.s.=