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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: Fluorapatite WS416 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: WS416

MINERAL_TYPE: Phosphate

MINERAL: Apatite-(CaF) [Fluorapatite]

FORMULA: Ca5(PO4)3F

FORMULA_HTML: Ca5(PO4)3F

COLLECTION_LOCALITY: Cerro de Mercado, Durango, Mexico

ORIGINAL_DONOR: Wards Scientific

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION: Individual light yellow brown hexagonal crystals.

IMAGE_OF_SAMPLE:
Photo of sample

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

A single crystal chip was x-rayed as unambiguous fluorapatite. (R. Driscoll)

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 0.578, 0.748, 0.802, and 0.868 microns resemble similar absorptions in neodymium oxide. A peak at 1.06 microns resembles a fluorescence feature but is at a relatively long wavelength.

The UV to NIR spectrum of this sample designated by "xtl" is of a crystal causing distinctly more intense absorption compared to spectra of its powder including a possible fluoresence peak at 1.06 microns. G. Swayze

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1a2a3a4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns