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(For further information on spectrsocopy, see:
http://speclab.cr.usgs.gov)
TITLE: Celsian HS200 DESCRIPT
DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: HS200
MINERAL_TYPE: Tectosilicate
MINERAL: Celsian (Feldspar group)
FORMULA: BaAl2Si2O8
FORMULA_HTML: BaAl2Si2O8
COLLECTION_LOCALITY: Australia
ORIGINAL_DONOR: Hunt and Salisbury Collection
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
Forms series with Orthoclase. Dimorphous with Paracelsian.
"This barium feldspar contains garnet and tourmaline as impurity. Its spectrum displays a very well defined and intense 1.9µ water feature with accompanying 1.4µ, 2.2µ, and 2.36µ features which are surprisingly weak."
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.
Sieve interval 74 - 250µm.
The impurities cause the large 2.0 band, and the weak features at 1.4 µm and in the 2.2-2.4 µm region. Celsian has no diagnostic spectral features in this spectral region. Roger N. Clark
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
Quartz - major component
Feldspar - major component (max microcline is best match)
Trioctahedral mica - more than a trace (phlogopite?)
Minor amounts of other minerals possible
Konnert, Judith and Marta Flohr, 1992, unpublished data, USGS Reston, VA.
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION:
None
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
Mode:
98-99 vol% celsian feldspar
1-2 vol% tourmaline (pleochroic, conchoidal fracture)
trace(garnet?, deep green)
Twins, two cleavages at 90 degrees, biaxial (-), low order interference color, 2-3 vol% fluid inclusions, some alteration (about 5 vol%). All consistent with celsian. Smaller (10-20 µm) grains coat larger grains up to 20-30% surface of larger grains. G. Swayze.
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1d2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
| LIB_SPECTRA_HED: | where | Wave Range | Av_Rs_Pwr | Comment |
|---|---|---|---|---|
| LIB_SPECTRA: | splib04a r 873 | 0.2-3.0µm | 200 | g.s.= 253 µm |
| LIB_SPECTRA: | splib05a r 1590 | 0.2-3.0µm | 200 | g.s.= |
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