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DOCUMENTATION_FORMAT: Man_Made
SAMPLE_ID: GDS794
MATERIAL_TYPE: Paint Pigment
MATERIAL: Paint Pigment
FORMULA: likely FeO(OH) plus clay(s)
FORMULA_HTML: likely FeO(OH) plus clay(s)
COLLECTION_LOCALITY: Phillips Collection, Washington, D.C
ORIGINAL_DONOR: Patricia Favero
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Lab
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Lab
SAMPLE_DESCRIPTION:
Dry powdered paint pigment from Kremer Pigments Inc.
Visual examination in sunlight indicates this sample is light brown.
IMAGE_OF_SAMPLE:
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EPMA, ICP(Trace), WChem
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION:
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
This pigment has spectral absorptions at 0.494, 0.661, and 0.965 microns typical of goethite. Sharp absorptions at 1.413 and 2.206 microns suggest the presence of clay with weaker absorptions at 2.305, 2.346, and 2.382 microns perhaps indicating other clay(s) or organics (continuum removed positions). G. Swayze
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1a2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns