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USGS Spectral Library Version 7 Sample Description

Kokaly, R.F., Clark, R.N., Swayze, G.A., Livo, K.E., Hoefen, T.M., Pearson, N.C., Wise, R.A., Benzel, W.M., Lowers, H.A., Driscoll, R.L., and Klein, A.J., 2017, USGS Spectral Library Version 7: U.S. Geological Survey Data Series 1035, 61 p., https://doi.org/10.3133/ds1035
For more information on the library, see: local link web link

TITLE: Pyrrhotite HS269 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS269.1B, HS269.2B, HS269.3B, HS269.4B

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 sulphides, 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."

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.

Grain size fractions are indicated by the extension after the sample number:
.1B = <5 µm
.2B = <74 µm
.3B = 74-250 µm
.4B = 250-1200 µm

IMAGE_OF_SAMPLE:
Photo of sample

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.

Szomolnokite (Major), Hydroniumjarosite(Major),Sulfer(minor),Pyrrhotite(minor), Titanite (trace). Sutley April, 2005.

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EPMA, 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_ # HS269.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1b2_3_4_ # HS269.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2c3c4u # HS269.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # HS269.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns