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(For further information on spectrsocopy, see:
http://speclab.cr.usgs.gov)
TITLE: Lepidocrosite GDS80 (Syn) DESCRIPT
DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: GDS80
MINERAL_TYPE: Hydroxide
MINERAL: Lepidocrosite (Synthetic)
FORMULA: gamma-FeO(OH)
FORMULA_HTML: gamma-FeO(OH)
COLLECTION_LOCALITY: Synthetic, Dave Sherman
ORIGINAL_DONOR: Dave Sherman
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
Polymorphous with Akaganeite, Feroxyhyte, and Geothite.
"This sample was synthesized by aerial oxidation of a FeCl2 solution at a pH or 6-7. The X ray diffraction pattern of this sample was extremely well-defined, implying a high degree of crystallinity."
The above description may apply to this sample. This sample was one of a series of samples made for the following paper:
Sherman, D.M., R.G. Burns, and V.M. Burns, 1982, Spectral characteristics of the iron oxides with application to the Martian bright region mineralogy. Journal of Geophysical Research, v. 87, n. B12, pp. 10169- 10180.
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
40 kV - 30 mA, 7.3-9.5 keV
File: lepicr80.out, -.mdi
Reference: JCPDS #8-98, 29-713
Found: lepidocrocite and goethite in subequal proportions
Sought: quartz (see comment)
Comment: Poorly crystallized: weak, broad reflections for both oxides. The goethite (110) and lepidocrocite (120) reflections are in the positions of the quartz (100) and (101) reflections and would prevent X-ray powder detection of a small amount of quartz, if present.
J.S. Huebner, J. Pickrell, T. Schaefer, written communication 1994, Reston, VA.
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem
COMPOSITION_TRACE:
COMPOSITION_DISCUSSION:
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
Because the spectra of lepidochrosite is expected to resemble that of goethite it is unknown to what extent the goethite contaminant spectrally interferes with the lepidochrosite spectral features in this sample. G. Swayze
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1?2_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 2727 | 0.2-3.0µm | 200 | g.s.= |
| LIB_SPECTRA: | splib05a r 4099 | 0.2-3.0µm | 200 | g.s.= |
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