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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: Montmorillonite CM20 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: CM20

MINERAL_TYPE: Phyllosilicate

MINERAL: Montmorillonite (Montmorillonite group)

FORMULA: (Na,Ca)0.33(Al,Mg)2Si4O10(OH)2*nH2O

FORMULA_HTML: (Na,Ca)0.33(Al,Mg)2Si4O10(OH)2•nH2O

COLLECTION_LOCALITY: Husband Mine, Polkville, Mississippi

ORIGINAL_DONOR: Clay Mineral Standard, Wards Natural Science Inc

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

A spectrum for 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.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Analysis by Norma Vergo indicates the sample is smectite + trace quartz, the less than 2µm cut was pure smectite.

END_XRD_ANALYSIS.

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


COMPOSITION
KEYWORD
Oxide
ASCII
Amount Weight
Percent, %
Oxide
html
COMPOSITION: SiO2 52.0 wt% SiO2
COMPOSITION: TiO2 0.17 wt% TiO2
COMPOSITION: Al2O3 18.3 wt% Al2O3
COMPOSITION: Fe2O3 5.18 wt% Fe2O3
COMPOSITION: FeO 0.02 wt% FeO
COMPOSITION: MnO 0.06 wt% MnO
COMPOSITION: MgO 3.32 wt% MgO
COMPOSITION: CaO 2.19 wt% CaO
COMPOSITION: Na2O less than 0.15 wt% Na2O
COMPOSITION: K2O 0.02 wt% K2O
COMPOSITION: P2O5 less than 0.05 wt% P2O5
COMPOSITION: H2O+ 7.56 wt% H2O+
COMPOSITION: H2O- 12.6 wt% H2O-
COMPOSITION: H2O 20.2 wt% H2O
COMPOSITION: LOI 18.9 wt% LOI
COMPOSITION: Total 100.34 wt%
COMPOSITION: O=Cl,F,S wt% #correction for Cl, F, S
COMPOSITION: New Total wt%

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

XRF Analysis by Branch of Analytical Chemistry, USGS, Denver. Total above includes LOI value rather than H2O values, and does not include value for FeO as it was determined at same time as H2O. Trace analysis was performed and will be added later.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Indicates no visible quartz, ~1% limonite individual grains.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

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: splib04a r 3177 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 4511 0.2-3.0µm 200 g.s.=


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