TITLE: Illite IMt-1 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: IMt-1

MINERAL_TYPE: Phyllosilicate

MINERAL: Illite, a group of hydrated mica-clay minerals

FORMULA: (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,H2O]

FORMULA_HTML: (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,H2O]

COLLECTION_LOCALITY: Silver Hill, Montana

ORIGINAL_DONOR: Clay Mineral Society Source Clay Mineral Repository

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

A spectrum of this sample was published by:

Clark, R.N., T.V.V. King, M. Klejwa, G. Swayze, and N. Vergo, 1990, High spectral resolution reflectance spectroscopy of minerals: J. Geophys Res. 12653-12680.

who noted that it was spectrally pure. Samples measured for the library include bulk (a) and <2µm fraction (b).

The spectrum from 2.5 to 25µm for this sample was published in:

Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Analysis by Norma Vergo indicates that the bulk sample is illite + quartz, <2µm separate is pure illite/smectite with 95% illite layers.

END_XRD_ANALYSIS.

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

COMPOSITION: SiO2 52.10 wt% SiO2
COMPOSITION: TiO2 0.79 wt% TiO2
COMPOSITION: Al2O3 21.90 wt% Al2O3
COMPOSITION: Fe2O3 6.44 wt% Fe2O3
COMPOSITION: MnO <0.02 wt% MnO
COMPOSITION: MgO 2.39 wt% MgO
COMPOSITION: CaO 1.07 wt% CaO
COMPOSITION: Na2O 0.30 wt% Na2O
COMPOSITION: K2O 7.84 wt% K2O
COMPOSITION: P2O5 0.10 wt% P2O5
COMPOSITION: LOI 6.91 wt% LOI
COMPOSITION: Total 99.56 wt%
COMPOSITION: O=Cl,F,S wt% #correction for Cl, F, S
COMPOSITION: New Total wt%

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

EM analysis by Gregg A. Swayze, Branch of Geophysics, USGS, Denver.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1_2_3_4_

LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment

LIB_SPECTRA: splib04a r 2362 0.2-3.0µm 200 g.s.= LIB_SPECTRA: splib04a r 2373 0.2-3.0µm 200 g.s.= <2µm

LIB_SPECTRA: splib05a r ____ 0.2-3.0µm 200 g.s.=

LIB_SPECTRA: splib06a r ____ 1.5-25µm 250 g.s.=