SAMPLE_ID: HS339.1B, HS339.2B, HS339.3B, HS339.4B
MINERAL: Monticellite (Olivine group)
ORIGINAL_DONOR: Hunt and Salisbury Collection
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
Forms series with Kirschsteinite.
Original spectrum published in: Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1973, Visible and near-infrared spectra of minerals and rocks: VI. Additional silicates. Modern Geology, v. 4, p. 85-106.
With the comment:"This sample is spectrally quite featureless except for a very weak band near 1.0µm and weak features in the visible. Although monticellite typically shows remarkably small departures from ideal composition, it is obvious that a small amount of Fe2+ has substituted for the Mg, producing both the 1µm band and the fall off toward the blue in the visible."
Grain size fractions are indicated by the extension after the sample number:
.1B = <5 µm
.2B = <74 µm
.3B = 74-250 µm
.4B = 250-1200 µm
40 kV - 30 mA, 6.5-9.5 keV
References: JCPDS #35-590
Found: Monticellite; weak reflections at 5.6, 2.45, 1.56, 1.42 Angstroms
Comment: Monticellite is well crystallized.
J.S.Huebner, J.Pickrell, T. Schaefer,written communication(USGS)
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EPMA, ICP(Trace), WChem
Sharp spectral absorptions at 1.4, 2.24, and 2.32 microns are from trace contaminants that increase in abundance as the grain size of the monticellite increases being most intense in the HS339.4B sample. G. Swayze.
SPECTRAL_PURITY: 1b2_3_4_ # HS339.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1b2_3_4_ # HS339.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2c3c4c # HS339.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # HS339.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns