TITLE: Illite GDS4 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: GDS4

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: Marble Head, WS

ORIGINAL_DONOR: Jim Crowley, USGS

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 the sample was darker than normal due to carbonaceous impurities, but was otherwise spectrally pure.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Analysis by Norma Vergo indicates that the sample is illite/smectite: 80% illite layers, R3 ordered, with trace amounts of feldspar. The <2µm separate is illite + illite/smectite.

END_XRD_ANALYSIS.

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


COMPOSITION: SiO2 51.62 wt% SiO2
COMPOSITION: TiO2 0.92 wt% TiO2
COMPOSITION: Al2O3 23.96 wt% Al2O3
COMPOSITION: Fe2O3 1.63 wt% Fe2O3
COMPOSITION: FeO 0.29 wt% FeO
COMPOSITION: MnO 0.01 wt% MnO
COMPOSITION: MgO 3.83 wt% MgO
COMPOSITION: SrO 0.74 wt% SrO
COMPOSITION: CaO 0.47 wt% CaO
COMPOSITION: Na2O 0.14 wt% Na2O
COMPOSITION: K2O 8.12 wt% K2O
COMPOSITION: P2O5 0.09 wt% P2O5
COMPOSITION: H2O+ 5.00 wt% H2O+
COMPOSITION: H2O- 2.90 wt% H2O-
COMPOSITION: LOI 6.91 wt% LOI
COMPOSITION: Total 99.41 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 at the Branch of Geophysics, USGS, Denver.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Sample not available.

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 2351 0.2-3.0µm 200 g.s.=

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

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