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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: Nickeline HS264 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS264

MINERAL_TYPE: Arsenate

MINERAL: Nickeline (Niccolite) (Nickelite group)

FORMULA: NiAs

FORMULA_HTML: NiAs

COLLECTION_LOCALITY: Elliot Lake, Ontario, Canada

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

"This sample is impure, containing a small amount of calcite. Despite this contaminant, the sample is spectrally featureless throughout the range. The calcite probably only serves to slightly raise its overall reflectivity."

Hunt, G.R., J.W. Salisbury, C.J. Lenhoff, 1971, Visible and Near-Infrared spectra of Minerals and Rocks: IV. Sulphides and Sulphates. Mod. Geol. 3, pp 1-14.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 7.3-9.6keV
File: cobl264_mdi, *.out (smear on a quartz plate)
References: JCPDS #31-300, 11-513
Found: Nickeline (niccolite), wurtzite, many unindexed strong reflections
Sought but not found: chalcocite, chalcopyrite, cobalite, covellite, marcasite, pyrite, pyrrhotite

Comment: Intensities do not match JCPDS data well. Optically, a large proportion of a colorless phase with poor cleavage and high birefringence - presumably the wurtzite. In the powder used for the X-ray data, the colorless phase is much coarser than the opaque(s). Will regrind and make another pattern.

XRD analysis by Steve Sutley indicates: nickelite (nickeline) (major), galena (major), calcite (minor), dolomite (minor), skutterudite (minor), cobaltite (minor), augite (trace)+ others?

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Silver-white metallic luster. G. Swayze We thought this sample was cobalite but XRD indicates otherwise.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1c2_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 1186 0.2-3.0µm 200 g.s.= 226 µm
LIB_SPECTRA: splib05a r 4939 0.2-3.0µm 200 g.s.=


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