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(For further information on spectrsocopy, see:
http://speclab.cr.usgs.gov)
TITLE: Jarosite GDS24 Na DESCRIPT
DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: GDS24
MINERAL_TYPE: Sulfate
MINERAL: Natro-Jarosite (Alunite group)
FORMULA: (Na)(Fe+3)3(SO4)2(OH)6
FORMULA_HTML: (Na)Fe3+3(SO4)2(OH)6
COLLECTION_LOCALITY: MIT Mineral Collection, Dave Sherman
ORIGINAL_DONOR: MIT Mineral Collection, Dave Sherman
CURRENT_SAMPLE_LOCATION: USGS Denver, Dave Sherman
ULTIMATE_SAMPLE_LOCATION: USGS Denver, Dave Sherman
SAMPLE_DESCRIPTION:
The spectrum looks like a beautiful jarosite spectrum with no contaminants. Roger N. Clark
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
Jarosite - major.
Unidentified residual in appreciable amounts; note peaks at 5.58,
5.5542, 2.769.
Konnert, Judith and Marta Flohr, 1992, unpublished data, USGS
Reston, VA.
40 kV - 30mA, 7.3-9.5 keV
File: najar24.mdi
References: JCPDS # 36-425; Huebner's reference patterns
Found: a jarosite mineral
Comment: Peaks are very narrow and the resolution of the alpha1-alpha2
reflections is good, indicating that GDS-24 is well crystallized and
compositionally homogenous. The relative peak intensities do not match
those of the JCPDS pattern or Huebner's reference patterns (see also
GDS-100, -101). The value of the c cell dimension, based on the (003),
(006), amd (009) reflections, is significantly smaller than that of
synthetic Na-jarosite.
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION:
Na-jarosite. .
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
Rhombohedral plates, moderate relief, straight extinction? Grains too small - may be length slow. All consistent with alunite (hydronium jarosite is part of Alunite Group) except for length slow? G. Swayze
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
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: | splib04a r 2467 | 0.2-3.0µm | 200 | g.s.= 15 µm |
| LIB_SPECTRA: | splib05a r 3648 | 0.2-3.0µm | 200 | g.s.= |
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