DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: GDS113
MINERAL_TYPE: Phyllosilicate
MINERAL: Muscovite (Mica group)
FORMULA: KAl2Si3O10(OH)2
FORMULA_HTML: KAl2Si3O10(OH)2
COLLECTION_LOCALITY: Brazil
ORIGINAL_DONOR: C.V. Clemency, SUNY
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, 6.5-9.5 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) small
sample size required smear mounts, which are responsible for
a strong preferred basal orientation in each of the patterns.
I'd be surprised if you found any differences in the optical
spectra of these eight micas."
J.S. Huebner, J. Pickrell, and J. Randow, 1993, written communication.
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: XRF # XRF, EM(WDS), ICP(Trace), WChem
| COMPOSITION: | SiO2 | 45.89 | wt% | SiO2 |
| COMPOSITION: | TiO2 | 0.32 | wt% | TiO2 |
| COMPOSITION: | Al2O3 | 35.64 | wt% | Al2O3 |
| COMPOSITION: | Fe2O3 | 1.08 | wt% | Fe2O3 |
| COMPOSITION: | FeO | 0.81 | wt% | FeO |
| COMPOSITION: | MnO | 0.02 | wt% | MnO |
| COMPOSITION: | MgO | 0.56 | wt% | MgO |
| COMPOSITION: | Na2O | 0.78 | wt% | Na2O |
| COMPOSITION: | K2O | 10.00 | wt% | K2O |
| COMPOSITION: | F | 0.23 | wt% | F |
| COMPOSITION: | H2O+ | 4.84 | wt% | H2O+ |
| COMPOSITION: | Total | 100.17 | wt% | |
| COMPOSITION: | O=Cl,F,S | 0.10 | wt% | #correction for Cl, F, S |
| COMPOSITION: | New Total | 100.07 | wt% |
Lin, F.C. and C.V. Clemency, 1981, Geochimica et Cosmochimica Acta 45, no. 4.
COMPOSITION_TRACE:
COMPOSITION_DISCUSSION:
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 3287 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r ____ 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib06a r ____ 1.5-25µm 250 g.s.=