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: Fluorapatite_REE WS418 xtl DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: WS418

MINERAL_TYPE: Phosphate

MINERAL: Apatite-(CaF) [Fluorapatite]

FORMULA: Ca5(PO4)3F

FORMULA_HTML: Ca₅(PO₄)₃F

COLLECTION_LOCALITY: Otter Lake, Quebec, Canada

ORIGINAL_DONOR: Wards Scientific

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION: Varicolored (mostly green) well formed hexagonal prismatic crystals in a pink calcite matrix.

IMAGE_OF_SAMPLE:

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Apatite (W. Benzel) High flourine content from microprobe analysis suggests this sample is fluorapatite. (T. Hoefen)

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: Sample has a number of sharp spectral absorptions (f-f orbital electronic transitions) throughout the 0.35 to 1.3 micron range presumably due to variable proportions of lanthanide series rare earth elements (i.e., Nd, Sm, and others). Bands at 0.582, 0.748, 0.803, and 0.868 microns resemble similar absorptions in neodymium oxide. Peaks at 1.06 and 1.16 microns resemble fluorescence features but are at relatively long wavelengths. (G. Swayze)

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1c2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns