DOCUMENTATION_FORMAT: MINERAL
SAMPLE_ID: GDS159
MINERAL_TYPE: Phyllosilicate
MINERAL: Clinochlore (Sheridanite) (Chlorite group)
FORMULA: (Mg,Fe+2)5Al(Si3Al)O10(OH)8
FORMULA_HTML: (Mg,Fe+2)5Al(Si3Al)O10(OH)8
COLLECTION_LOCALITY: Frisco Mine, California?
ORIGINAL_DONOR: Jim Post
CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory
SAMPLE_DESCRIPTION:
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
40 kV - 30 mA, 6.5-9.5 keV (sheridan.out=sherd9.out)
Reference: JCPDS #12-242
Found: Chlorite type IIb; weak but sharp reflection at
9.3 degrees 2 theta; (mica?); weak reflection at 3.13 angstroms (albite?)
Sought but not found: quartz
Comments: An excellent chlorite pattern; sharp reflections indicate
good crystallinity. The chemical analysis is that of a
clinochlore.
J.S. Huebner, J. Pickrell, and T. Schaefer, 1994, written communication.
40 kV - 30 mA, 6.5-9.5 keV
File: sherd159.out, -.mdi (smear mount on quartz plate)
References: Bailey (1988 in Clays and Clay Minerals 36, 193-213); JCPDS #25-177,
35-731, 21-1276; Huebner's referecnce patterns
Found: Clinoclore type IIbb, weak reflection at 9.4 angstroms (mica?), 3.24 angstroms
(sphene(?), 3.12 angstroms (La-monazite?)
Comment: Very sharp reflections indicate high degree of crystallinity and
compositional homogeneity. Position of (060) reflection consistent with Mg/(Mg+Fe+Mn)
= 1.00. Optically, about modeal 1% "heavy" minerals (huge index and birefringence).
Rutile has its strongest reflection at 3.24 angstroms but was not found optically
(compare with GDS-158, "rutilated clinochlore").
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: XRF # XRF, EM(WDS), ICP(Trace), WChem
| COMPOSITION: | SiO2 | 31.3 | wt% | SiO2 |
| COMPOSITION: | TiO2 | 0.20 | wt% | TiO2 |
| COMPOSITION: | Al2O3 | 19.4 | wt% | Al2O3 |
| COMPOSITION: | Cr2O3 | 0.004 | wt% | Cr2O3 |
| COMPOSITION: | Fe2O3 | 1.16 | wt% | Fe2O3 |
| COMPOSITION: | MnO | 0.02 | wt% | MnO |
| COMPOSITION: | MgO | 34.7 | wt% | MgO |
| COMPOSITION: | CaO | 0.04 | wt% | CaO |
| COMPOSITION: | Na2O | 0.20 | wt% | Na2O |
| COMPOSITION: | K2O | 0.01 | wt% | K2O |
| COMPOSITION: | P2O5 | 0.01 | wt% | P2O5 |
| COMPOSITION: | LOI | 13.3 | wt% | LOI |
| COMPOSITION: | Total | 100.344 | wt% | |
| COMPOSITION: | O=Cl,F,S | wt% | #correction for Cl, F, S | |
| COMPOSITION: | New Total | wt% |
Jim Post, 1993, written communication.
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION:
None
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
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 1099 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r ____ 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib06a r ____ 1.5-25µm 250 g.s.=