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DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: WS319a
MINERAL_TYPE: Carbonate
MINERAL: Calcite (REE-bearing)
FORMULA: CaCO3
FORMULA_HTML: CaCO3
COLLECTION_LOCALITY: Snowbird Mine, Mineral County, Montana, USA
ORIGINAL_DONOR: Wards Scientific
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION: Light brown stained dolomite matrix with dark brown parisite crystals also with the same catalog number WS319.
IMAGE_OF_SAMPLE:
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
X-ray diffraction analysis suggests dolomite with minor calcite. Trace to minor calcite was identified with slightly shifted peaks suggesting element substitution in the calcite crystal lattice, which may be due to substitution of rare earth elements. R. Driscoll.
Dolomite is major phase with a trace of calcite. REE were not observed in survey chemistry by handheld X-ray fluorescence with a detection limit of ~400 ppm. B. Benzel.
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EPMA, ICP(Trace), WChem
COMPOSITION_TRACE:
COMPOSITION_DISCUSSION:
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION: There are absorptions (f-f orbital electronic transitions) in the 0.7 to 1.0 micron region presumably due to variable proportions of lanthanide series rare earth elements (i.e., Nd, Sm, and others). Weak bands at 0.741, 0.800, and 0.864 microns resemble similar absorptions in neodymium oxide. A C-O related absorption at 2.336 microns is close to endmember calcite composition so the crystal with the rare earth elements is the minor calcite identified in XRD analyses. G. Swayze.
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1b2_3_4_ # WS319a # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns