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(For further information on spectrsocopy, see:
http://speclab.cr.usgs.gov)
TITLE: Chalcedony CU91-6A DESCRIPT
DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: CU91-6A
MINERAL_TYPE: Tectosilicate
MINERAL: Chalcedony (var. of Quartz)
FORMULA: SiO2
FORMULA_HTML: SiO2
COLLECTION_LOCALITY: Cuprite, Nevada
ORIGINAL_DONOR: Greg Swayze
COLLECTION_LATITUDE: N37 32.43' # degrees and decimal minutes (N or S)
COLLECTION_LONGITUDE: W117 10.25' # degrees and decimal minutes (W or E) P> DATUM: NAD27 # coordinate datum
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
SEM analyses shows crystal morphology indicative of chalcedony. G. Swayze
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
Quartz, from Steve Sutley, written communication, 1992
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION:
none
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
none
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
Spectrum has absorptions characteristic of chalcedony with a strong OH fist overtone band at 1.4211 microns, a structual water band at 1.9193 microns, and a Si-OH combination band at 2.2164 microns. The 1.4211 micron band lacks a shoulder on the long wavelength side of the absorption indicating that this sample does not contain detectable amounts of opal.
See: Swayze, G.A., 1997, The hydrothermal and structural history of the Cuprite Mining District, southwestern Nevada: an integrated geological and geophysical approach: unpublished Ph.D. Dissertation, University of Colorado at Boulder, 399p.
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 894 | 0.2-3.0µm | 200 | g.s.= |
| LIB_SPECTRA: | splib05a r 1602 | 0.2-3.0µm | 200 | g.s.= |
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