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: Alunite GDS95 Na Syn (150C) DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: GDS95

MINERAL_TYPE: Sulfate

MINERAL: Na-Alunite

FORMULA: NaAl3(SO4)2(OH)6

FORMULA_HTML: NaAl₃(SO₄)₂(OH)₆

COLLECTION_LOCALITY: Not available

ORIGINAL_DONOR: Roger Stroffregen

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Synthetically prepared pure Na-endmember sample made at 150C. Sample is 100% mole fraction Na.

See Stroffregen, R.E., and C.N. Alpers, Observations on the unit-cell dimensions, H2O contents, and delD values of natural and synthetic alunite, American Mineralogist, 77, 1092-1098, 1992.

IMAGE_OF_SAMPLE:

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

see: Stroffregen, R.E., and C.N. Alpers, Observations on the unit-cell dimensions, H2O contents, and delD values of natural and synthetic alunite, American Mineralogist, 77, 1092-1098, 1992.

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

Sample has relatively weak vibrational features between 1.4 - 1.5, 1.76,and 2.17 microns. Other pure Na-endmember alunites prepared at higher temperatures have much stronger vibrational features.

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:	splib05a r 436	1.3-5.3µm	200	g.s.=
LIB_SPECTRA:	splib06a r 1269			g.s.=