Clark and others 2007 USGS Data Series 231
Spectral Library splib06a Sample Description

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

TITLE: Quartz HS32 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS32

MINERAL_TYPE: Tectosilicate

MINERAL: Quartz

FORMULA: SiO2

FORMULA_HTML: SiO₂

COLLECTION_LOCALITY: Rock Springs, Arkansas

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

This particular sample is a very pure variety of clear crystal quartz, and careful grinding has produced a sample with very high reflectivity and almost devoid of spectral features. There are only two very weak features at 2.3 and 2.5µm in the finest grain sizes. Because there are no bands at 1.4µm or 1.9µm, these features cannot be attributed to water or hydroxyl groups in the quartz. The cross-overs of the two very fine grain sizes with the others is not significant.

Hunt, G.R., J.W. Salisbury, 1970, Visible and near-infrared spectra of minerals and rocks: I. Silicate minerals. Modern Geology, v. 1, p. 283-300.

Sieve interval 74-250µm.

Results of petrographic examination: Crystal clear quartz.

Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263.

IMAGE_OF_SAMPLE:

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Pure. (Norma Vergo)

Pure quartz.

Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263.

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

Results of XRF or other compositional analysis: Essentially pure SiO₂ within the limit of microprobe error.

Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Colorless transparent. No contamination visually apparent.

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 4135	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib05a r 5854	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib06a r 19141			g.s.=