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USGS Spectral Library Version 7 Sample Description

Kokaly, R.F., Clark, R.N., Swayze, G.A., Livo, K.E., Hoefen, T.M., Pearson, N.C., Wise, R.A., Benzel, W.M., Lowers, H.A., Driscoll, R.L., and Klein, A.J., 2017, USGS Spectral Library Version 7: U.S. Geological Survey Data Series 1035, 61 p., https://doi.org/10.3133/ds1035
For more information on the library, see: local link web link

TITLE: Clinochlore GDS158 Flagstaff 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.

IMAGE_OF_SAMPLE:
Photo of sample

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: clinochlore 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, EPMA, 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: 1b2b3b4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns