TITLE: Chalcopyrite HS431 DESCRIPT
MINERAL: Chalcopyrite (Chalcopyrite group)
ORIGINAL_DONOR: Hunt and Salisbury Collection
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
Forms series with Eskebornite.
Spectra for this sample were originally published in: Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1971, Visible and near-infrared spectra of minerals and rocks: IV. Sulphides and sulphates. Modern Geology, v. 3, p. 1-14.
With the note: "It exhibits typical opaque behaviour, decreasing in reflectivity as its particle size is reduced. It is not, however, spectrally featureless. A fall-off in the reflectivity toward the blue, together with a weak band near 0.9µm, results in the characteristic brass-yellow color of this mineral. Both spectral features are due to iron, which is present in chalcopyrite in the trivalent state (Deer et al., 1962). The copper also makes a contribution to the feature near 0.9µm. This sample is contaminated with approximately 10% pyrrhotite, which has no appreciable effect on the spectrum."
Sample measured for the library was the 74-250µm sieve interval.
40 kV - 30 mA, 7.3-9.5 keV
File: chpyr431.mdi, *.out (smear mount on quartz plate)
References: JCPDS #37-471, #5-566; Huebner's reference patterns
Found: Chalcopyrite, minor sphalerite
Comment: Moderately sharp, symmetrical peaks suggest moderate crystallinity and compositional heterogeneity. Sphalerite lattice spacings consistent with ZnS composition (Fe-poor sphalerite).
J.S. Huebner, J. Pickrell, and T. Schaefer, 1994, written communication.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem
95 vol% chalcopyrite (yellow-gold color)
5 vol% pyrrhotite (slightly magnetic)
Opaque, yellow-gold metallic luster, uneven fracture. G. Swayze.
LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment
LIB_SPECTRA: splib04a r 905 0.2-3.0µm 200 g.s.= 246 µm
LIB_SPECTRA: splib05a r ____ 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib06a r ____ 1.5-25µm 250 g.s.=