DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: PYX02.a, PYX02.b, PYX02.c, PYX02.d, PYX02.e, PYX02.f, PYX02.g, PYX02.h
MINERAL_TYPE: Inosilicate
MINERAL: Hypersthene (Fe-rich enstatite, Pyroxene group)
FORMULA: (Mg,Fe+2)2Si2O6
FORMULA_HTML: (Mg,Fe+2)Si2O6
COLLECTION_LOCALITY: Bamble, Norway
ORIGINAL_DONOR: Wards Scientific, and Robert B. Singer
CURRENT_SAMPLE_LOCATION: U.S.G.S. Denver Spectroscopy Laboratory.
ULTIMATE_SAMPLE_LOCATION: U.S.G.S. Denver Spectroscopy Laboratory.
SAMPLE_DESCRIPTION:
Intermediate member of the series Enstatite-Orthoferrosilite. The
original sample description and vis-nir spectrum was published by:
Singer, R.B., 1981, Near-Infrared spectral reflectance of mineral
mixtures: Systematic combinations of pyroxenes, olivine, and iron
oxides: J. Geophys Res., v. 86, p. 7967-7982.
The sample is pure pyroxene except for a small (less than 2%?)
amount of amphibole (possibly tremolite).
The amphibole absorption features appear
in the spectra as weak, narrow bands at 2.3 m and 1.4 m.
Singer suspected the tremolite contamination and the amphibole features are
in the higher resolution spectra in this library support that.
The sample was ground and wet sieved in methanol at the USGS Denver Spectroscopy Laboratory by Roger Clark. SEM photos were done by R. Clark on each sieve interval to characterize the grain sizes.
Grain size fractions are indicated by the extension after the sample number:
.g = 5-10 microns
.a = 10-20 microns
.d = 20-30 microns
.e = 30-45 microns
.f = 45-104 microns
.b = 104-150 microns
.c = 150-250 microns
.h = >250 microns
IMAGE_OF_SAMPLE:
NO PHOTO
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
None
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: XRF
COMPOSITION KEYWORD |
Oxide ASCII |
Amount | Weight Percent, % |
Oxide html |
---|---|---|---|---|
COMPOSITION: | SiO2 | 55.30 | wt% | SiO2 |
COMPOSITION: | TiO2 | 0.05 | wt% | TiO2 |
COMPOSITION: | Al2O3 | 0.12 | wt% | Al2O3 |
COMPOSITION: | Fe2O3 | (as FeO) | wt% | Fe2O3 |
COMPOSITION: | FeO | 9.38 | wt% | FeO |
COMPOSITION: | MnO | 0.15 | wt% | MnO |
COMPOSITION: | MgO | 32.80 | wt% | MgO |
COMPOSITION: | Na2O | 0.00 | wt% | Na2O |
COMPOSITION: | P2O5 | 0.01 | wt% | P2O5 |
COMPOSITION: | LOI | 2.00 | wt% | LOI |
COMPOSITION: | Total | 100.28 | wt% | |
COMPOSITION: | O=Cl,F,S | wt% | #correction for Cl, F, S | |
COMPOSITION: | New Total | 100.28 | wt% |
COMPOSITION_TRACE:
None
COMPOSITION_DISCUSSION:
The compositional analysis is from: Singer, R.B., 1981, Near-Infrared spectral reflectance of mineral mixtures: Systematic combinations of pyroxenes, olivine, and iron oxides: J. Geophys Res., v. 86, p. 7967-7982.
All Fe2O3 is reported in the FeO amount. The analysis was performed by XRA Laboratory, Ontario Canada. FeO was by wet chemistry, all else by XRF.
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
The sample appears to be pure pyroxene except for a small (less than ~ 2%) amount of tremolite.
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1c2c3b4b # Hypersthene PYX02.a # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2c3b4b # Hypersthene PYX02.b # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2c3b4b # Hypersthene PYX02.c # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2c3b4b # Hypersthene PYX02.d # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2c3b4b # Hypersthene PYX02.e # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2c3b4b # Hypersthene PYX02.f # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2c3b4b # Hypersthene PYX02.g # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2c3b4b # Hypersthene PYX02.h # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns