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(For further information on spectroscopy, 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.
IMAGE_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, 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_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
| 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.= |
| LIB_SPECTRA: | splib06a r 5327 | g.s.= | ||
| LIB_SPECTRA: | splib06a r 5341 | g.s.= |