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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: Cookeite CAr-1 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: SC-CAr-1

MINERAL_TYPE: Phyllosilicate

MINERAL: Cookeite (Chlorite group)

FORMULA: LiAl4(Si3Al)O10(OH)8

FORMULA_HTML: LiAl4(Si3Al)O10(OH)8

COLLECTION_LOCALITY: N. Little Rock, ARK

ORIGINAL_DONOR: Clay Mineral Society, Source Clay Repository

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Sample was ground in an alumina mortar and pestle and wet sieved with methanol into less than 30µm (c), 30-45µm, 60-104µm (b), and 104-150µm (a) size fractions. (Letter denotes spectrum designation.)

King, T.V.V. and R.N. Clark, 1989, Spectral Characteristics of Chlorites and Mg-Serpentines Using high-Resolution Reflectance Spectroscopy. Jour. Geophys. Res., 13.997-14,008.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Sample is cookeite plus medium amount of calcite. The sample is spectrally pure. XRD analysis by Norma Vergo.

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.

END_XRD_ANALYSIS.

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

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Up to 2 vol% quartz impurity, cookeite has low relief, first order gray color, biaxial (+), no calcite observed in x-polarized light. No fizz with HCl, so calcite identification by XRD appears to be in error. Suggest new XRD analysis.

All properties are consistent with chlorite. G. Swayze.

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 1206 0.2-2.7µm 200 g.s.= 115µm
LIB_SPECTRA: splib04a r 1217 0.2-2.7µm 200 g.s.= 70µm
LIB_SPECTRA: splib04a r 1228 0.2-2.7µm 200 g.s.= 15µm
LIB_SPECTRA: splib05a r 2126 0.2-2.7µm 200 g.s.= 115µm
LIB_SPECTRA: splib05a r 2138 0.2-2.7µm 200 g.s.= 70µm
LIB_SPECTRA: splib05a r 2150 1.3-5.3µm 200 g.s.= 15µm
LIB_SPECTRA: splib05a r 2189 0.2-2.7µm 200 g.s.=


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