DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: GDS116, GDS116a
MINERAL_TYPE: Phyllosilicate
MINERAL: Muscovite (Mica group)
FORMULA: KAl2Si3O10(OH)2
FORMULA_HTML: KAl2Si3O10(OH)2
COLLECTION_LOCALITY: Tanzania
ORIGINAL_DONOR: C.V. Clemency, SUNY (Jim Post)
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
Sample is composed of gray/green sand size particles.
GDS116 particle size is not specified.
GDS116a particle size is greater than 37 microns.
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
40 kV - 30 mA, 7.2-9.5 keV
References: Bailey (1984, p. 574), Huebner's reference patterns
Found: dioctahedral mica, 2M1 polytype
Sought but not found: quartz, (100) would be distinct if present
Comments: Very similar patterns. Only mica detected. The mica (004)
reflection is at 17.6-17.9 degrees 2 theta; indicating a large alkali
such as potassium (the dioctahedral Na-mica, paragonite,
has the (004) reflection at 18.4 degrees). The small sample size
required smear mounts, which are responsible for a strong
preferred basal orientation in each of the patterns."
J.S. Huebner, J. Pickrell, and J. Randow, 1993, written communication.
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: XRF # XRF, EPMA, ICP(Trace), WChem
COMPOSITION KEYWORD |
Oxide ASCII |
Amount | Weight Percent, % |
Oxide html |
---|---|---|---|---|
COMPOSITION: | SiO2 | 45.90 | wt% | SiO2 |
COMPOSITION: | TiO2 | 0.46 | wt% | TiO2 |
COMPOSITION: | Al2O3 | 31.06 | wt% | Al2O3 |
COMPOSITION: | Fe2O3 | 4.35 | wt% | Fe2O3 |
COMPOSITION: | FeO | 1.42 | wt% | FeO |
COMPOSITION: | MnO | 0.05 | wt% | MnO |
COMPOSITION: | MgO | 1.38 | wt% | MgO |
COMPOSITION: | CaO | 0.07 | wt% | CaO |
COMPOSITION: | Na2O | 0.43 | wt% | Na2O |
COMPOSITION: | K2O | 10.21 | wt% | K2O |
COMPOSITION: | F | 0.11 | wt% | F |
COMPOSITION: | H2O+ | 4.82 | wt% | H2O+ |
COMPOSITION: | Total | 100.26 | wt% | |
COMPOSITION: | O=Cl,F,S | 0.05 | wt% | #correction for Cl, F, S |
COMPOSITION: | New Total | 100.21 | wt% |
Lin, F.C. and C.V. Clemency, 1981, Geochimica and Cosmochimica Acta, v.45, no.4.
COMPOSITION_TRACE:
COMPOSITION_DISCUSSION:
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1a2a3a4a # GDS116 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1a2_3_4_ # GDS116a # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns