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: Jarosite GDS98 K 90C Syn DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: GDS98

MINERAL_TYPE: Sulfate

MINERAL: Jarosite (K-Jarosite) (Synthetic) (Alunite group)

FORMULA: K(Fe+3)3(SO4)2(OH)6

FORMULA_HTML: KFe⁺³₃(SO₄)₂(OH)₆

COLLECTION_LOCALITY: Synthetic

ORIGINAL_DONOR: Roger Stroffregen, SMU

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Sample synthesized at 90C

IMAGE_OF_SAMPLE:

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 7.3-6.5 keV
Reference: JCPDS #22-827 (jarosite)
Found: Jarosite

Comment: Sharp patterns (GDS99 is exceptional) indicate good crystallinity and compositional homogeneity. All reflections are accounted for by the JCPDS card. However, the samples are not identical. GDS98 has cell hexagonal dimensions a = 7.313(1) and c = 17.060(4) Angstroms whereas GDS99 has a = 7.302(1) and c = 17.214(2) Angstroms. The difference in c is significant and suggests a composition difference between the two samples. Are there differences in the optical spectra?"

J.S. Huebner, J. Pickrell, and J. Randow, 1993, written communication.

END_XRD_ANALYSIS.

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

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

There is a slight longward shift to the 2.26 micron absorption in the Beckman spectrum relative to the more accurate position of this same band in the Nicolet FTIR data. The other bands in the Beckman spectrum appear to match those of the nicolet data better.

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1a2a3a4_ # 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 2436	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib05a r 3660	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib05a r 3672	1.3-5.3µm	200	g.s.=
LIB_SPECTRA:	splib06a r 11375			g.s.=
LIB_SPECTRA:	splib06a r 11387			g.s.=
LIB_SPECTRA:	splib06a r 11426			g.s.=