DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: HS313.1B, HS313.3B, HS313.4B, HS313.6
MINERAL_TYPE: Phyllosilicate
MINERAL: Glauconite (Mica group)
FORMULA: (K,Na)(Fe+3,Al,Mg)2(Si,Al)4O10(OH)2
FORMULA_HTML: (K,Na)(Fe+3,Al,Mg)2(Si,Al)4O10(OH)2
COLLECTION_LOCALITY: South Dakota
ORIGINAL_DONOR: Hunt and Salisbury Collection
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
Grain size fractions are indicated by the extension after the sample number:
.1B = <5 µm
.3B = 74-250 µm
.4B = 250-1200 µm
.6 = cut slab
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
Quartz - major component
1M mica (phlogopite, glauconite) - major component
Konnert, Judith and Marta Flohr, 1992, unpublished data, USGS Reston, VA.
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EPMA, ICP(Trace), WChem
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION:
No analysis.
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
Optical examination gives the following mineral mode:
70 vol% glauconite
population 1: average grain size= 230µm 65 vol%
population 2: average grain size= 8µm 5 vol%
30 vol% quartz and feldspar grains
population 3: average grain size= 260µm 30 vol%
average grain size populations = 234µm
Large rounded glauconite grains whose surfaces are 60% covered with smaller glauconite. Some of the quartz and feldspar grains are Fe-stained and partially glauconite coated. Glauconite grains have slight yellow-green pleochroism. G. Swayze
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1c2_3_4_ # Glauconite HS313.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2c3c4c # Glauconite HS313.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # Glauconite HS313.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1c2_3_4_ # Glauconite HS313.6 # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns