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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: Topaz Wigwam_Area_3_#13 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: Wigwam_Area_3_#13

MINERAL_TYPE: Nesosilicate

MINERAL: Topaz

FORMULA: Al2SiO4(F,OH)2

FORMULA_HTML: Al2SiO4(F,OH)2

COLLECTION_LOCALITY: Wigwam Creek #3, Colorado

ORIGINAL_DONOR: Gene Foord

CURRENT_SAMPLE_LOCATION: Gene Foord, USGS

ULTIMATE_SAMPLE_LOCATION: Gene Foord, USGS

SAMPLE_DESCRIPTION:

Most of the (OH-) in topaz is generally replaced by F-, the maximum fluorine content being 20.7%.

Hurlbut, C.S., and C. Klein, 1977, Manual of Mineralogy, 19th Ed. John Wiley and Sons, New York, New York, 353p.

Topaz is commonly found as a vapor phase or hydrothermal crystallization product in three principal geologic associations: rhyolites; pegmatities and greisens; and hydrothermal veins. The mineral also occurs as a liquidus phase in ongonites and some rhyolites.

Foord, E.L., L. Jackson, J. Taggart, J. Crock, and T.V.V. King, 1988, Environment of Crystallization of Topaz as Determined From Crystal Chemistry and Infrared Spectra. Program and Abstracts Annual GSA Meeting, October 31-November 3, 1988, Denver CO, A224,#4128.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Not Available

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

H2O- = 0.03, H2O+= 0.32

Compositions of the 65 topaz samples are grouped in terms of H2O+, F, and trace element content. H2O+ contents for (in wt. %) for rhyolitic topaz ranged from 0.06 to 0.11, pegmatitic topaz from 0.20 to 0.91, and hydrothermal topaz from 1.69 to 2.67; fluorine content is inversely related to water content. This is a pegmatitic topaz.

Foord, E.L., L. Jackson, J. Taggart, J. Crock, and T.V.V. King, 1988, Environment of Crystallization of Topaz as Determined From Crystal Chemistry and Infrared Spectra. Program and Abstracts Annual GSA Meeting, October 31-November 3, 1988, Denver CO, A224,#4128.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2_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 4837 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 6812 0.2-3.0µm 200 g.s.=


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