TITLE: Clinochlore_Fe GDS157 Chlorite DESCRIPT DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: GDS157

MINERAL_TYPE: Phyllosilicate

MINERAL: Ferroan Clinochlore (Ripidolite) (Chlorite group)

FORMULA: (Fe+2,Mg)5Al(Si3Al)O10(OH)8

FORMULA_HTML: (Fe+2,Mg)5Al(Si3Al)O10(OH)8

COLLECTION_LOCALITY: Flagstaff Hill, California

ORIGINAL_DONOR: Jim Post

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

This sample is described in:

Post, J.L. and C.C. Plummer, 1972, The chlorite series of Flagstaff Hill area, California: A preliminary investigation. Clays and Clay Minerals, v.20, pp271-283.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 6.5-9.5 keV, smear mount (ripidolt.out); 45 kV - 35 mA, 7.3- 9.5 keV, random mount (ripidlt2.out)
References: Bailey (1988), Huebner's reference patterns
Found: Chlorite, type IIb, one weak but distinct reflection at 9.7 angstroms (mica?), and one very weak reflection at 7.7 angstroms.
Sought but not found: quartz

Comments: Many sharp relections indicate very good crystallinity. Ripidlt2 is one of the best chlorite patterns I have ever seen. The chemical analysis places this chlorite in the composition range once called ripidolite. Note that the unidentified reflection at 7.7 angstroms is also present in sheridanite GDS158."

J.S. Huebner, J. Pickrell, and J. Randow, 1993, written communication.

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: # XRF


COMPOSITION: SiO2 25.2 wt% SiO2
COMPOSITION: TiO2 0.90 wt% TiO2
COMPOSITION: Al2O3 19.6 wt% Al2O3
COMPOSITION: Cr2O3 0.057 wt% Cr2O3
COMPOSITION: Fe2O3 25.3 wt% Fe2O3
COMPOSITION: NiO 0.051 wt% NiO
COMPOSITION: MnO 0.11 wt% MnO
COMPOSITION: MgO 16.6 wt% MgO
COMPOSITION: CaO 0.11 wt% CaO
COMPOSITION: Na2O 0.27 wt% Na2O
COMPOSITION: K2O 0.03 wt% K2O
COMPOSITION: LOI 10.0 wt% LOI
COMPOSITION: Total 98.228 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:

Low order gray interference color, green pleochroic color, basal cleavage, all consistent with chlorite. No other mica obvious, some brown Fe staining present in some grains. 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 1076 0.2-3.0µm 200 g.s.=

LIB_SPECTRA: splib06a r ____ 1.5-25µm 250 g.s.=

LIB_SPECTRA: splib05a r ____ 0.2-3.0µm 200 g.s.=