DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: NMNH137044
MINERAL_TYPE: Nesosilicate
MINERAL: Olivine (Fosterite-Fayalite series)(Olivine group)
FORMULA: (Mg,Fe)2SiO4 Fo92
FORMULA_HTML: (Mg,Fe)2SiO4 Fo92
COLLECTION_LOCALITY: Chavira Mine, Kamargo (nr), Chihuahau, Mexico
ORIGINAL_DONOR: Smithsonian
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
The sample consists of many 0.5cm particles plus one large fragment. Under petrographic microscope, the hand-picked sample appears clean but one of the grains may be pyroxene.
Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263.
Sample is in two sieve intervals: (a) 74-250µm and (b) <74µm.
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
Pure forsterite.
Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263.
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: EM(WDS) # XRF, EM(WDS), ICP(Trace), WChem
| COMPOSITION: | SiO2 | 40.27 | wt% | SiO2 |
| COMPOSITION: | TiO2 | 0.01 | wt% | TiO2 |
| COMPOSITION: | Al2O3 | 0.02 | wt% | Al2O3 |
| COMPOSITION: | FeO | 8.70 | wt% | FeO |
| COMPOSITION: | MnO | 0.15 | wt% | Mn0 |
| COMPOSITION: | MgO | 52.28 | wt% | MgO |
| COMPOSITION: | CaO | 0.06 | wt% | CaO |
| COMPOSITION: | Na2O | 0.02 | wt% | Na2O |
| COMPOSITION: | K2O | 0.01 | wt% | K2O |
| COMPOSITION: | Total | 101.52 | wt% |
COMPOSITION_TRACE:
COMPOSITION_DISCUSSION:
Microprobe analysis of hand-picked grains showed the sample to be homogenous within and between grains. Average of 10 analyses showed the sum of the divalent cations too high, but Fo content is approximately 92 mole percent.
Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263.
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
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 3559 0.2-3.0µm 200 160µm
LIB_SPECTRA: splib04a r 3577 0.2-3.0µm 200 <74µm
LIB_SPECTRA: splib05a r ____ 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib06a r ____ 1.5-25µm 250 g.s.=