DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: GDS120
MINERAL_TYPE: Phyllosilicate
MINERAL: Muscovite (Mica group)
FORMULA: KAl2Si3O10(OH)2
FORMULA_HTML: KAl2Si3O10(OH)2
COLLECTION_LOCALITY: Pegma Mine, Inyo Co., California
ORIGINAL_DONOR: Jim Post
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
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 | 45.89 | wt% | SiO2 |
COMPOSITION: | TiO2 | 0.29 | wt% | TiO2 |
COMPOSITION: | Al2O3 | 35.69 | wt% | Al2O3 |
COMPOSITION: | Fe2O3 | 2.33 | wt% | Fe2O3 |
COMPOSITION: | MnO | 0.03 | wt% | MnO |
COMPOSITION: | MgO | 0.25 | wt% | MgO |
COMPOSITION: | ZnO | 0.02 | wt% | ZnO |
COMPOSITION: | BaO | 0.01 | wt% | BaO |
COMPOSITION: | CaO | 0.10 | wt% | CaO |
COMPOSITION: | Na2O | 0.47 | wt% | Na2O |
COMPOSITION: | K2O | 9.94 | wt% | K2O |
COMPOSITION: | H2O+ | 4.38 | wt% | H2O+ |
COMPOSITION: | Total | 99.75 | wt% | |
COMPOSITION: | O=Cl,F,S | wt% | #correction for Cl, F, S | |
COMPOSITION: | New Total | wt% |
Jim Post, personal communication, 1991.
COMPOSITION_TRACE:
COMPOSITION_DISCUSSION:
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1a2a3a4_ # GDS120 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns