SAMPLE_ID: HS103.1B, HS103.2B, HS103.3B, HS103.4B, HS103.6
MINERAL: Microcline (Feldspar group)
COLLECTION_LOCALITY: Crystal Peak, Colorado
ORIGINAL_DONOR: Hunt and Salisbury Collection
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
Dimorphous with Orthoclase.
"This spectrum (103B) displays as its major feature a broad band near 1.3µ similar to the ferrous ion band in the two anorthite's above. This sample is quite pure in hand specimen, but Deer and others (1963) note that alkali feldspars are a series varying from pure KAlSi3O8 (microcline) to pure NaAlSi3O8 (albite) but they normally also contain a small amount of CaAl2-Si2O8 (anorthite). It appears that the anorthite fraction of this microcline contains substituted ferrous iron as in the anorthite's above, which also accounts for the bands in the visible at 0.38 and 0.42µ. Weak bands at 1.9 and 2.5µ are due to included water, while the 2.2µ band is due to the combination involving the AlOH bend."
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.
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
.6 = cut slab
Max. microcline + albite(L) + quartz(m)
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EPMA, ICP(Trace), WChem
Not done yet
A spectral feature near 2.2 microns suggests the presence of trace quantities of a kaolin group mineral. G. Swayze.
SPECTRAL_PURITY: 1c2_3_4_ # HS103.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # HS103.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2c3c4_ # HS103.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # HS103.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # HS103.6 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns