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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: Microcline HS103 Feldspar DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS103

MINERAL_TYPE: Tectosilicate

MINERAL: Microcline (Feldspar group)

FORMULA: KAlSi3O8

FORMULA_HTML: KAlSi3O8

COLLECTION_LOCALITY: Crystal Peak, Colorado

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Dimorphous with Orthoclase.

"This spectrum (103B) displays as its major feature a broad band near 1.3µ similar to the ferrous ion band in the two anorthite's above. This sample is quite pure in hand specimen, but Deer et al. (1963) note that alkali feldspars are a series varying from pure KAlSi3O8 (microcline) to pure NaAlSi3O8 (albite) but they normally also contain a small amount of CaAl2-Si2O8 (anorthite). It appears that the anorthite fraction of this microcline contains substituted ferrous iron as in the anorthite's above, which also accounts for the bands in the visible at 0.38 and 0.42µ. Weak bands at 1.9 and 2.5µ are due to included water, while the 2.2µ band is due to the combination involving the AlOH bend."

Sieve interval 74 - 250µm.

Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1973, Visible and near-infrared spectra of minerals and rocks: VI. Additional silicates. Modern Geology, v. 4, p. 85-106.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Max. microcline + albite(L) + quartz(m)

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Not done yet

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1c2_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 2990 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 4354 0.2-3.0µm 200 g.s.=


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