TITLE: Diaspore HS416 DESCRIPT
COLLECTION_LOCALITY: Rosebud, MO
ORIGINAL_DONOR: Hunt and Salisbury Collection
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
"Dimorph. with Boehmite. This sample is impure and is a mixture of bauxite minerals including gibbsite, kaolinite and a very small amount of a ferruginous material. Longward of 1.3µm the reflectance of the sample decreases. The sample has a 1.4 µm absorption (overtone of the hydroxyl) and a 1.8 µm absorption which is believed to be a displaced 1.9µm resulting from the presence of a free H2O molecule."
Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1971, Visible and near-infrared spectra of minerals and rocks: III. Oxides and hydroxides. Modern Geology, v. 2, p. 195-205.
XRD_ANALYSIS: Pure diaspore.
Konnert, Judith and Marta Flohr, 1992, unpublished data, USGS Reston, VA.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem
Bimodal grain size distribution:
pop 1 = 268 µm at 92 vol%
pop 2 = 10 µm at 8 vol%
avg grain size = 257 µm
Small grains coat larger grains. Large grains are translucent and this makes it difficult to obtain optical properties. I recomment that this sample be x-rayed for proper identification. No fizz with HCl. G. Swayze.
LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment
LIB_SPECTRA: splib04a r 1388 0.2-3.0µm 200 g.s. = 257 µm
LIB_SPECTRA: splib05a r ____ 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib06a r ____ 1.5-25µm 250 g.s.=