U.S. Geological Survey home page

USGS Spectral Library Version 7 Sample Description

Kokaly, R.F., Clark, R.N., Swayze, G.A., Livo, K.E., Hoefen, T.M., Pearson, N.C., Wise, R.A., Benzel, W.M., Lowers, H.A., Driscoll, R.L., and Klein, A.J., 2017, USGS Spectral Library Version 7: U.S. Geological Survey Data Series 1035, 61 p., https://doi.org/10.3133/ds1035
For more information on the library, see: local link web link

TITLE: Oxide_of_chromium GDS795 DESCRIPT

DOCUMENTATION_FORMAT: Man_Made

SAMPLE_ID: GDS795

MATERIAL_TYPE: Paint Pigment

MATERIAL: Paint Pigment

FORMULA:Cr2O3

FORMULA_HTML: Cr2O3

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 medium green.

IMAGE_OF_SAMPLE:
Photo 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 two diagnostic reflectance peaks at 0.411 and 0.538 microns forming a double upward spike profile. Absorption bands between and forming the peaks are located at 0.468 and 0.613 microns the latter forming an absorption edge centered at about 0.73 microns. The NIR portion of the spectrum is dominated by a relatively weak broad electronic absorption centered at 1.219 microns (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