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Clark et. al. 2003 USGS Open File Report 03-395
Spectral Library splib05a Sample Description

(For further information on spectrsocopy, see: http://speclab.cr.usgs.gov)

TITLE: Andradite WS474 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: WS474

MINERAL_TYPE: Nesosilicate

MINERAL: Andradite (Garnet group)

FORMULA: Ca3(Fe3+)2(SiO4)3

FORMULA_HTML: Ca3Fe3+2(SiO4)3

COLLECTION_LOCALITY: Navajo Reservation, Arizona

ORIGINAL_DONOR: Ward Science Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Forms two series with Grossular and with Schorlomite.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 7.3-9.5 keV
File: pyro474.out, *.mdi
References: Borg and Smith (1969), JCPDS #15-742, DHZ, v. 1a (1982), Huebner's reference patterns
Found: Garnet; unindexed weak reflection at 3.32 angstroms

Comment: Sharp reflections indicate good degree of crystallization and suggest chemical homogeneity. Garnet ao=12.00 angstroms, inconsistent with pyrope but consistent with a andradite-rich or uvarovite-rich composition. On the basis of brown color, the garnet composition is andradite-rich. The weak unindexed reflection is consistent with the possible presence of a trace of a feldspar.

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: EM(WDS) # XRF, EM(WDS), ICP(Trace), WChem

COMPOSITION
KEYWORD
Oxide
ASCII
Amount Weight
Percent, %
Oxide
html
COMPOSITION: SiO2 35.855 wt% SiO2
COMPOSITION: TiO2 0.033 wt% TiO2
COMPOSITION: Al2O3 0.085 wt% Al2O3
COMPOSITION: Cr2O3 0.011 wt% Cr2O3
COMPOSITION: V2O3 0.011 wt% V2O3
COMPOSITION: FeO 30.817 wt% FeO
COMPOSITION: NiO 0.014 wt% NiO
COMPOSITION: MnO 0.676 wt% MnO
COMPOSITION: MgO 0.041 wt% MgO
COMPOSITION: CaO 33.509 wt% CaO
COMPOSITION: Total 101.06 wt%

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment
LIB_SPECTRA: splib04a r 4049 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 1012 0.2-3.0µm 200 g.s.=


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