U.S. Geological Survey home page


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: Pyrrhotite HS269 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS269

MINERAL_TYPE: Sulfide

MINERAL: Pyrrhotite (Nickeliferous)

FORMULA: Fe1-xS

FORMULA_HTML: Fe1-xS

COLLECTION_LOCALITY: Ontario

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

"SS-20. Pyrrhotite. Ontario (269B). Pyrrhotite, Fe1-xS, is a common accessory mineral of igneous rocks, particularly basic ones. It is often found in high temperature veins and occasionally in pegmatites. It occurs in large masses associated with other sulphides, especially nickel suphides, of uncertain origin. This sample is nickeliferous, containing a small amount of pentlandite (?), together with a very small amount of anhydrite. It displays opaque and spectrally featureless behavior throughout this spectral range."

Sieve interval 74 - 250µm.

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.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 7.3-9.5 keV
File: pyrht269.out, -.mdi
References: JCPDS # 24-200, 29-724, 29-723
Found: pyrrhotite, very weak additional phase(s)

J.S.Huebner, J.Pickrell, T. Schaefer, written communication (1994 USGS)

Comment: Broader peaks with multiple alpha1 suggest heterogeneity between the different pyrrhotite polytypes. Pyrrhotite 3T and 5T provide the best match on major in intensities. There are seven broad, very weak unindexed reflections that do not correlate with any of the pyrrhotite polytypes suggesting an additional phase.

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2_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 4103 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 5808 0.2-3.0µm 200 g.s.=


USA.gov logo  Take Pride in America button