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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: Chlorite + Epidote + Calcite GDS312 - GDS314, GDS319 DESCRIPT

DOCUMENTATION_FORMAT: MIXTURE

SAMPLE_ID: GDS312, GDS313, GDS314, GDS319

MIXTURE_TYPE: Intimate

MIXTURE: Chlorite + Epidote + Calcite

FORMULA: (Mg,Fe)3(Si,Al)4O10(OH)2-(Mg,Fe)3(OH)6 + Ca2(Al,Fe+3)3(SiO4)3(OH) + CaCO3

FORMULA_HTML: (MgFe)3(SiAl)4O10(OH)2-(MgFe)3(OH)6 +Ca2(Al,Fe+3)3(SiO4)3(OH) + CaCO3

COLLECTION_LOCALITY: Calcite from Mexico and Epidote from Prince Wales Island, and Chlorite from Flagstaff Hill, California.

ORIGINAL_DONOR: Purchased from Egger's Lapidary

COLLECTION_LATITUDE: Not Available # degrees and decimal minutes (N or S)

COLLECTION_LONGITUDE: Not Available # degrees and decimal minutes (W or E)

DATUM: Not Available # coordinate datum

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Samples constructed from ground and seived pure minerals GDS157 (chlorite), GDS297 (epidote), and GDS298 (calcite) in variable proportions.
20wt% Chlorite + 60wt% Epidote + 20 wt% Calcite GDS312
60wt% Chlorite + 20wt% Epidote + 20 wt% Calcite GDS313
20wt% Chlorite + 20wt% Epidote + 60 wt% Calcite GDS314
33wt% Chlorite + 33wt% Epidote + 33 wt% Calcite GDS319

For further information pertaining to this sample see: Dalton, B.J., Bove, D., Mladinich, C., Clark, R.N., Rockwell, B., Swayze, G.A., King, T., Church, S., Spectral Classification Of Similar Materials Using the Tetracorder Algorithm: the Calcite-Epidote-Chlorite Problem, Proceedings of the Tenth JPL Airborne Earth Science Workshop, Jet Propulsion Laboratory Publication 02-1, pp.93-101.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Samples were identified as pure.

For further information pertaining to this sample see: Dalton, B.J., Bove, D., Mladinich, C., Clark, R.N., Rockwell, B., Swayze, G.A., King, T., Church, S., Spectral Classification Of Similar Materials Using the Tetracorder Algorithm: the Calcite-Epidote-Chlorite Problem, Proceedings of the Tenth JPL Airborne Earth Science Workshop, Jet Propulsion Laboratory Publication 02-1, pp.93-101.

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

None

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

Spectra have absorptions characteristic of chlorite, epidote, and calcite. Because these are intimate mixtures the dark components dominate spectrally. In the 0.35 - 2 micron region the strong Fe absorptions of chlorite dominate the spectra. In the 2 - 2.5 micron region chlorite and epidote absorptions dominate with little evidence of the calcite 2.34 micrion absorption.

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1a2_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 7779 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 7818 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 7841 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 7863 0.2-3.0µm 200 g.s.=


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