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(For further information on spectroscopy, see:
http://speclab.cr.usgs.gov)
TITLE: Alunite-K GDS84 Na03 DESCRIPT
DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: GDS84
MINERAL_TYPE: Sulfate
MINERAL: Alunite (Alunite Group)
FORMULA: KAl3(SO4)2(OH)6
FORMULA_HTML: KAl3(SO4)2(OH)6
COLLECTION_LOCALITY: Marysvale, Utah, USA
ORIGINAL_DONOR: Roger Stroffregen
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
Coarse vein alunite from Marysvale hydrothermal deposit.
IMAGE_OF_SAMPLE:
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
GDS84 K-alunite 40 kV - 30 mA, 6.5-9.5 keV File: kalnt84.out, *.mdi (smear mount on quartz plate) References: JCPDS #14-136; GDS-97B Found: Alunite Comment- Moderately sharp reflections; the (003)-(101) doublet is poorly resolved, in contrast to GDS-97B. There may be compositional heterogeneity. Weak to very weak reflections do not appear on the JCPDS card; they could be alunite reflections, or they could be caused by trace quantities of impurities. Lattice spacing's are smaller than those that JCPDS #14-136 report for an alunite from the same locality, Marysvale, Utah.
see: Stroffregen, R.E., and C.N. Alpers, Observations on the unit-cell dimensions, H2O contents, and delD values of natural and synthetic alunite, American Mineralogist, 77, 1092-1098, 1992.
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: NONE #XRF, EM(WDS), ICP(Trace),WChem
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION:
Sample has 3 mole % Na and 97 mole % K from atomic absorption analysis. Stroffregen, R., and Alpers, C., 1992, Observations on the unit-cell dimensions, H2O contents and del D values of natural and synthetic alunite: American Mineralogist, v.77, p. 1092-1098.
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
Sample has relatively strong vibrational features between 1.4 - 1.5, 1.77, and 2.0 - 2.24, 2.32, and a complex centered at 2.5 microns.
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1a2a3a4_ # 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 204 | 0.2-3.0µm | 200 | g.s.= 260µm |
| LIB_SPECTRA: | splib05a r 386 | 0.2-3.0µm | 200 | g.s.= |
| LIB_SPECTRA: | splib05a r 398 | 1.3-5.3µm | 200 | g.s.= |
| LIB_SPECTRA: | splib06a r 1175 | g.s.= | ||
| LIB_SPECTRA: | splib06a r 1187 | g.s.= | ||
| LIB_SPECTRA: | splib06a r 1226 | g.s.= |