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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: Albite HS143 Plagioclase DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS143.1B, HS143.2B, HS143.3B, HS143.4B, HS143.6

MINERAL_TYPE: Tectosilicate

MINERAL: Oligoclase (Plagioclase, Feldspar group)

FORMULA: (Na,Ca)Al(Al,Si)Si2O8

FORMULA_HTML: (Na,Ca)Al(Al,Si)Si2O8

COLLECTION_LOCALITY: Norway

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Most analyses contain small amounts of Na, but a complete solid solution series is possible from orthoclase toward intermediate albite. Crystallizes at intermediate temperatures and has a partially ordered Al-Si distribution.

Grain size fractions are indicated by the extension after the sample number:
.1B = <5 µm
.2B = <74 µm
.3B = 74-250 µm
.4B = 250-1200 µm
.6 = cut slab

IMAGE_OF_SAMPLE:
Photo of sample

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Albite + microcline (s) (Norma Vergo)

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EPMA, ICP(Trace), WChem

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

No compositional analyses.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

Presence of a 2.2 micron absorption indicates likely mica contamination. There is also a 0.7 micron peak in the spectrum of sample HS143.2Bdue to stray light from a fluorescent lamp. G. Swayze.

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2_3_4_ # HS143.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # HS143.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2c3c4_ # HS143.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # HS143.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1d2_3_4_ # HS143.6 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns