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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: Topaz Wigwam_Area_A_#10 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: Wigwam_Area_A_#10

MINERAL_TYPE: Nesosilicate

MINERAL: Topaz

FORMULA: Al2SiO4(F,OH)2

FORMULA_HTML: Al2SiO4(F,OH)2

COLLECTION_LOCALITY: Wigwam Creek, Colorado, Area A

ORIGINAL_DONOR: Gene Foord

CURRENT_SAMPLE_LOCATION: Gene Foord Collection, USGS

ULTIMATE_SAMPLE_LOCATION: Gene Foord Collection, 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; pegmatites 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.

IMAGE_OF_SAMPLE:
NO PHOTO

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Not Available

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: # XRF, EPMA, ICP(Trace), WChem

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

H2O- = 0.01, H2O+= 0.26

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: 1b2b3b4_ # Wigwam_Area_A_#10 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns