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(For further information on spectrsocopy, see:
http://speclab.cr.usgs.gov)
TITLE: Jarosite WS368 (Pb) DESCRIPT
DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: WS368
MINERAL_TYPE: Sulfate
MINERAL: Pb-bearing jarosite (Alunite group)
FORMULA: Pb(Fe+3)6(SO4)4(OH)12
FORMULA_HTML: PbFe+36(SO4)4(OH)12
COLLECTION_LOCALITY: Tombstone, Arizona
ORIGINAL_DONOR: Wards Science Collection
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
40 kV - 30 mA, 6.5-9.5 keV (plumjaro.out), 7.3-9.5 keV (plumjar2.out,
pbjaro3.out)
References: JCPDS #18-698, 22-827, and 5-417; Szymanski (1985);
pattern for K-jarosite GDS98
Found: an alunite, probably K-jarosite, plus subordinate cerussite
and quartz.
Sought but not found: plumbojarosite
Comments: Three phases found. Uncorrected alunite 2 theta values
were refined to a hexagonal/rhombohedral unit cell having a=7.301
(2) and c=17.050(7). These dimensions and the yellowish ochre color
suggest that the alunite is Fe-rich; the pattern closely matches
that of K-jarosite except that the strong (012) reflection is
missing. There is no evidence of the double cell (c=33.8 angstroms)
characteristic of plumbojarosite (in which a large divalent cation
replaces the alkali).
J.S. Huebner,J. Pickrell, T. Schaefer, unpublished data, written communication, USGS, Reston, VA (1994).
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem
COMPOSITION_TRACE:
COMPOSITION_DISCUSSION:
Comparison with a spectrum of cerussite indicates that any cerussite is not detected spectrally. Since the spectral features of this sample differ from those of low temperature K-jarosite (GDS98), this may indicate the presence of Pb in the sample. Because this sample also contains some cerussite, any chemical analysis must be done on the jarosite portion only. This has yet to be done. G. Swayze.
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1c2_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 2498 | 0.2-3.0µm | 200 | g.s.= |
| LIB_SPECTRA: | splib05a r 3834 | 0.2-3.0µm | 200 | g.s.= |
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