DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: SHCa-1
MINERAL_TYPE: Phyllosilicate
MINERAL: Hectorite (Montmorillonite group)
FORMULA: Na0.33(Mg,Li)3Si4O10(F,OH)2
FORMULA_HTML: Na0.33(Mg,Li)3Si4O10(F,OH)2
COLLECTION_LOCALITY: San Bernadino, California
ORIGINAL_DONOR: Grim Collection
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
Trioctahedral lithium montmorillonite (stored in H20).
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
Hectorite + quartz (m) + calcite (L) + dolomite (s)? (Norma Vergo)
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: XRF # XRF, EM(WDS), ICP(Trace), WChem
| COMPOSITION: | SiO2 | 34.7 | wt% | SiO2 |
| COMPOSITION: | TiO2 | 0.038 | wt% | TiO2 |
| COMPOSITION: | Al2O3 | 0.69 | wt% | Al2O3 |
| COMPOSITION: | Fe2O3 | 0.02 | wt% | Fe2O3 |
| COMPOSITION: | FeO | 0.25 | wt% | FeO |
| COMPOSITION: | MnO | 0.008 | wt% | MnO |
| COMPOSITION: | MgO | 15.3 | wt% | MgO |
| COMPOSITION: | CaO | 23.4 | wt% | CaO |
| COMPOSITION: | Li2O | 2.18 | wt% | Li2O |
| COMPOSITION: | Na2O | 1.26 | wt% | Na2O |
| COMPOSITION: | K2O | 0.13 | wt% | K2O |
| COMPOSITION: | P2O5 | 0.014 | wt% | P2O5 |
| COMPOSITION: | F | (2.60) | wt% | F |
| COMPOSITION: | F | (2.75) | wt% | F |
| COMPOSITION: | S | 0.01 | wt% | S |
| COMPOSITION: | LOI | 21.80 | wt% | LOI |
| COMPOSITION: | Total | 99.80 | wt% | |
| COMPOSITION: | O=Cl,F,S | wt% | #correction for Cl, F, S | |
| COMPOSITION: | New Total | wt% |
COMPOSITION_TRACE:
None
COMPOSITION_DISCUSSION:
None
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
Mode:
99 vol% hectorite
1 vol% quartz
tr opaques (metallic luster)
Bimodal Grain Size Distribution:
mode 1: 204 µm @ 80 vol%
mode 2: 25 µm @ 20 vol%
avg gr sz = 183 µm
This sample was treated with acetate to dissolve carbonates. There is no fizz with HCl. Clay grains have sweeping extinction, quartz present but no evidence of calcite or dolomite. All consistent with a fairly pure sample of hectorite. G. Swayze.
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1_2_3_4_
LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment
LIB_SPECTRA: splib04a r 1974 0.2-3.0µm 200 g.s.= 183 µm
LIB_SPECTRA: splib04a r 1985 0.2-3.0µm 200 g.s.= 183 µm
LIB_SPECTRA: splib05a r ____ 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib06a r ____ 1.5-25µm 250 g.s.=