Clark et. al. 2003 USGS Open File Report 03-395
Spectral Library splib05a Sample Description

(For further information on spectrsocopy, see: http://speclab.cr.usgs.gov)

TITLE: Opal WS732 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: WS732

MINERAL_TYPE: Tectosilicate

MINERAL: Opal

FORMULA: SiO2*nH2O

FORMULA_HTML: SiO₂•nH₂O

COLLECTION_LOCALITY: Pershing Co., Nevada

ORIGINAL_DONOR: Wards Scientific

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
File: opal732.out, -.mdi
References: Tada and Iiyama (1983, p. 232); Isaacs et al. (1983, p. 258)
Found: opal having affinity to cristobalite
Quartz sought: no sign of quartz

Comment: 4 broad reflections in positions of strong cristobalite reflections. One of these reflections (4.1 angstroms) is extremely intense. Weak, broad reflection at 2.1 angstroms not explained.

J.S. Huebner, J. Pickrell, T. Schaefer, written communication 1994

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:

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 3745	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib05a r 5267	0.2-3.0µm	200	g.s.=

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U.S. Department of the Interior | U.S. Geological Survey URL: https://pubsdata.usgs.gov/pubs/of/2003/ofr-03-395/DESCRIPT/M/opal_ws732.html Questions or Assistance: USGS Web Contact Page Last Modified: Sat Jan 12 23:29 EDT 2013