Sample Description USGS Spectral Library Version 7

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
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TITLE: Spessartine WS481 Garnet DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: WS481

MINERAL_TYPE: Nesosilicate

MINERAL: Spessartine (Garnet group)

FORMULA: Mn3Al2(SiO4)3

FORMULA_HTML: Mn₃Al₂(SiO₄)₃

COLLECTION_LOCALITY: Shamburu, Kenya

ORIGINAL_DONOR: Ward Natural Science Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Forms series with Almandine.

IMAGE_OF_SAMPLE:
NO PHOTO

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Spessartine is major phase with a trace amount of quartz. Handheld portable XRF confirms Mn content with ~3% Ca available to substitute into structure or make another garnet below XRD detection limit. B. Benzel.

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

Weak sharp absorptions in the 2.7 micron region indicate the presence of a hydroxyl-bearing phase(s). G. Swayze.

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2c3c4_ # WS481 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns