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DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: HS108.3B
MINERAL_TYPE: Tectosilicate
MINERAL: Microcline (Feldspar group)
FORMULA: KAlSi3O8
FORMULA_HTML: KAlSi3O8
COLLECTION_LOCALITY: Perth, Ontario
ORIGINAL_DONOR: Hunt and Salisbury Collection
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
Dimorphous with Orthoclase.
"The microcline spectra (108B) shows fairly weak H2O features near 1.4 and 1.9µ, and a very weak feature near 2.2µ due to the OH stretch-AlOH bend combination. It also displays a quite sharp drop off at approximately 0.55µ which is typical of the ferric oxides. Sample is pinkish in color, which is not due to an alteration coating of ferric oxide. Deer and others (1963) point out that Fe3+ may substitute for Al in limited amount in normal alkali feldspars, but excess Fe3+ will exsolved either as discrete particles of iron-bearing mineral, or as an iron staining on grain boundaries and cleavage planes. The latter appears to be the case for this microcline, which explains the ferric oxide type of visible spectrum. There is, however, insufficient ferric oxide present to yield a discernible near-infrared feature."
Sieve interval 74 - 250µm.
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.
IMAGE_OF_SAMPLE:
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
Maximum microcline + albite(large)
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EPMA, ICP(Trace), WChem
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION:
None
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
Not done yet
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1c2b3b4u # HS108.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns