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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: Clinochlore GDS158 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: GDS158

MINERAL_TYPE: Phyllosilicate

MINERAL: Clinochlore, Chlorite

FORMULA: (Mg,Fe2+)5Al((Si3Al)O10(OH)8

FORMULA_HTML: (Mg,Fe2+)5Al(Si3Al)O10(OH)8

COLLECTION_LOCALITY: Flagstaff Hill, California ORIGINAL_DONOR: Jim Post CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory SAMPLE_DESCRIPTION:

This sample described in:

Post, J.L. and C.C. Plummer, 1972, The chlorite series of Flagstaff Hill area, California: A preliminary investigation. Clays and Clay Minerals, v.20, pp271-283.

Clinochlore was previously called Sheridanite. END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

45 kV - 35 mA, 6.5-9.5 keV, smear mount (sherd8.out); 40 kV - 30 mA, random mount (sherd8-2.out) References: Bailey (1988, MSA Reviews 19; 1988 in Clays and Clay Minerals); Huebner's reference patterns Found: Chlorite type IIbb. A broad, very weak reflection at 9.6 is probably due to a trace of mica. A weak reflection at 3.23 angstroms may be due to a trace of feldspar. A weak unidentified reflection at 2.357 angstroms. And a weak, unidentified reflection at 7.8 angstroms that also appeared in GDS157 (the "ripidolite"). Sought but not found: quartz Comments: With chemical analysis, the chlorite is a clinochlore IIbb. Severe preferred orientation in smear mounts; fortunately, there was enough sample for a random mount. Sharp chlorite reflections indicate excellent crystallinity. With GDS157 ("ripidolite"), the best chlorite patterns I have ever seen." J.S. Huebner, J. Pickrell, and T.Schaefer, 1994, written communication. 40 kV- 30 mA, 7.3-9.5 keV File sherd158.out, -.mdi (edge/random mount) References: Bailey (1988 in Clays and Clay Minerals, 36, 193-213); Huebner's reference patterns Found: clinichlore type IIbb, trace rutile Comment: Sharp reflections suggest excellent crystallinity and compositional homogeneity. Position of the (060) reflection indicates Mg/(Mg+Fe+Mn) = 0.85. Presence of rutile confirmed optically; rutile forms thin but very elongate needles in the chlorite flakes ("rutilated clinochlore").

END_XRD_ANALYSIS.

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


COMPOSITION
KEYWORD
Oxide
ASCII
Amount Weight
Percent, %
Oxide
html
COMPOSITION: SiO2 27.5 wt% SiO2
COMPOSITION: TiO2 1.04 wt% TiO2
COMPOSITION: Al2O3 19.8 wt% Al2O3
COMPOSITION: Cr2O3 0.057 wt% Cr2O3
COMPOSITION: Fe2O3 14.10 wt% Fe2O3
COMPOSITION: NiO 0.074 wt% NiO
COMPOSITION: MnO 0.13 wt% MnO
COMPOSITION: MgO 24.7 wt% MgO
COMPOSITION: CaO 0.10 wt% CaO
COMPOSITION: Na2O 0.22 wt% Na2O
COMPOSITION: K2O 0.03 wt% K2O
COMPOSITION: P2O5 0.11 wt% P2O5
COMPOSITION: LOI 11.5 wt% LOI
COMPOSITION: Total 99.361 wt%
COMPOSITION: O=Cl,F,S wt% #correction for Cl, F, S
COMPOSITION: New Total wt%
COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

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 1088 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 1898 0.2-3.0µm 200 g.s.=


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