TITLE: Clinochlore GDS159 Chlorite DESCRIPT

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.=