TITLE: Cobaltite HS264 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS264

MINERAL_TYPE: Sulfide

MINERAL: Cobaltite (Cobaltite group)

FORMULA: CoAsS

FORMULA_HTML: CoAsS

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.

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

mode:
60 vol% calcite (with cobaltite inclusions)
40 vol% cobaltite

Silver-white metallic luster. This is consistent with cobaltite. Suggest wash this sample with HCl to remove calcite. G. Swayze.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1_2_3_4_

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 ____ 0.2-3.0µm 200 g.s.=

LIB_SPECTRA: splib06a r ____ 1.5-25µm 250 g.s.=