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: Muscovite, CU91-250A med Al DESCRIPT

DOCUMENTATION_FORMAT: MIXTURE

SAMPLE_ID: CU91-250A

MIXTURE_TYPE: Intimate

MIXTURE: medium low Al-muscovite + quartz

FORMULA: KAl2(Si3Al)O10(OH,F)2 + SiO2

FORMULA_HTML: KAl₂(Si₃Al)O₁₀(OH,F)₂ + SiO₂

COLLECTION_LOCALITY: Cuprite, Nevada, USA

ORIGINAL_DONOR: Gregg Swayze

COLLECTION_LATITUDE: N37deg 31.767' # degrees and decimal minutes (N or S)

COLLECTION_LONGITUDE: W117deg 13.517' # 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:

Sample is a hydrothermally altered phyllite of the Lower Cambrian Harkless formation from west of Hwy 95, collected along the southwestern margin of the western center.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Quartz (major), muscovite (both 2M1 and 1M polytypes)

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: EM(WDS) #XRF, EM(WDS), ICP(Trace),WChem

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

Electron microprobe analyses of several muscovite crystals gives an octahedral Al content of 1.762 (cation number based on 11 oxygen's) An estimate of the octahedral Al base on the wavelength position of the 2.2 micron Al-OH combination band is 1.707.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

none

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

Spectrum has vibrational absorptions typical of muscovite. Quartz in this sample has no spectral features in this spectral range (1.35 - 2.5 microns). The first OH stretch overtone is located at 1.4121 microns and the Al-OH combination band is located at 2.2017 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 8684	1.3-5.3µm	200	g.s.=

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