DOCUMENTATION_FORMAT: Man_Made
SAMPLE_ID: GDS810
MATERIAL_TYPE: Paint Pigment
MATERIAL: Paint Pigment
FORMULA: Fe3O4
FORMULA_HTML: Fe3O4
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 Natural Pigments, LLC
Visual examination in sunlight indicates this sample is black.
Image is very dark and was collected under lighting conditions identical to that used to photograph the other paint pigments in this chapter.
END_SAMPLE_DESCRIPTION.
Visual examination indicates this sample is black.
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 absorptions consistent with magnetite at 0.510 and 1.135 microns, the later band being very asymmetric toward longer wavelengths. Overall reflectance is less than 2%. The very weak band at 1.77 micron may be related to organic contaminants (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