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USGS Spectral Library Version 7 Sample Description

Kokaly, R.F., Clark, R.N., Swayze, G.A., Livo, K.E., Hoefen, T.M., Pearson, N.C., Wise, R.A., Benzel, W.M., Lowers, H.A., Driscoll, R.L., and Klein, A.J., 2017, USGS Spectral Library Version 7: U.S. Geological Survey Data Series 1035, 61 p., https://doi.org/10.3133/ds1035
For more information on the library, see: local link web link

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:

IMAGE_OF_SAMPLE:
Photo of sample

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 and others (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, EPMA, 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_ # WS732 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns