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: Fluorapatite WS416 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: WS416

MINERAL_TYPE: Phosphate

MINERAL: Fluorapatite (Apatite group)

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:

Spectrum shows weak Nd⁺³ bands.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 6.5-9.5 keV
Reference: JCPDS #15-876 (synthetic fluorapatite); Hughes et al.

Found: Apatite (only)
Sought but not found: Quartz

Cell dimension: a=9.3922(4), c=6.8825(6) Angstroms, using Si internal standard.

Comment: apatite, probably near fluorapatite endmember composition. An extraordinarily clear pattern with many sharp peaks indicating high degree of crystallinity and compositional homogeneity. Synthetic fluorapatite reported to have a=9.3684 and c=6.8841 Angstroms, and natural fluorapatite, a=9.398 and c=6.878 Angstroms. Although the cell dimensions of WS416 appear similar to those of the analyzed natural fluorapatite, the cell dimensions of the reference synthetic and natural fluorapatites do not agree. Thus, there is uncertainty in the composition of WS416.

J.S. Huebner,J. Pickrell, T. Schaefer unpublished data, written communication, USGS, Reston, VA (1994)

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1a2_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 1657	0.2-3.0µm	200	g.s.=
LIB_SPECTRA:	splib05a r 2699	0.2-3.0µm	200	g.s.=

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U.S. Department of the Interior | U.S. Geological Survey URL: https://pubsdata.usgs.gov/pubs/of/2003/ofr-03-395/DESCRIPT/M/fluorapatite_ws416.html Questions or Assistance: USGS Web Contact Page Last Modified: Sat Jan 12 23:30 EDT 2013