DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: HS188
MINERAL_TYPE: Nesosilicate
MINERAL: Staurolite
FORMULA: Fe(+2)2Al9O6(SiO4)4(O,OH)2
FORMULA_HTML: Fe2+2Al9O6(SiO4)4(O,OH)2
COLLECTION_LOCALITY: Fannin County, Georgia
ORIGINAL_DONOR: Hunt and Salisbury Collection
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
N-14 Staurolite 188B--Fannin Co., Georgia. (Fe2+, Mg)2(Al, Fe3+)9O6 (SiO4)4(O, OH)2: Staurolite, like kyanite and sillimanite is a typical mineral found in medium grade metamorphosed argillaceous rocks. It is produced at a lower temperature-pressure than is kyanite. This spectrum shows strong general absorption to both long and short wavelengths which produces an apparent reflectivity maximum near 1.05 µ. The fall off to longer wavelengths must be due to generalized hydroxyl and water absorptions and is quite similar in appearance to the spectrum of diaspore (see Part III, p. 200, spectrum (-6). The fall off in the visible must be due to absorptions by ferrous and ferric iron.
Sieve interval 74 - 250µm.
Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1973, Visible and near-infrared spectra of minerals and rocks: VI. Additional silicates. Modern Geology, v. 4, p. 85-106.
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
40 kV - 30 mA, 7.3-9.5 keV
File: staur188.out, -.mdi
References: JCPDS # 41-1484; Huebner's reference patterns
Found: quartz, staurolite, K-mica
Comment: All components appear well crystallized and in significant representation
with quartz
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem
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 4615 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.=
COMPOSITION_TRACE: