U.S. Geological Survey home page


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: Almandine WS479 Garnet DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: WS479

MINERAL_TYPE: Nesosilicate

MINERAL: Almandine (Garnet group)

FORMULA: (Fe+2)3Al2(SiO4)3

FORMULA_HTML: Fe+23Al2(SiO4)3

COLLECTION_LOCALITY: Ampandrambaika, Malagasy

ORIGINAL_DONOR: Ward Science Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Forms series with Pyrope and with Spessartine.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Not Available

END_XRD_ANALYSIS.

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


COMPOSITION
KEYWORD
Oxide
ASCII
Amount Weight
Percent, %
Oxide
html
COMPOSITION: SiO2 37.34 wt% SiO2
COMPOSITION: TiO2 0.08 wt% TiO2
COMPOSITION: Al2O3 21.93 wt% Al2O3
COMPOSITION: Cr2O3 0.02 wt% Cr2O3
COMPOSITION: V2O3 0.02 wt% V2O3
COMPOSITION: FeO 32.23 wt% FeO
COMPOSITION: NiO 0.01 wt% NiO
COMPOSITION: MnO 1.70 wt% MnO
COMPOSITION: MgO 8.83 wt% MgO
COMPOSITION: CaO 1.62 wt% CaO
COMPOSITION: Total 103.78 wt%
COMPOSITION: O=Cl,F,S wt% #correction for Cl, F, S
COMPOSITION: New Total 103.78 wt%

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

avg. grain size = 125µm Range = 10 - 295µm

Trace of opaques, conchoidal fractured garnet grains, with 15% of garnet grains containing non-isotropic inclusions. G. Swayze.

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 193 0.2-3.0µm 200 g.s.= 125 µm
LIB_SPECTRA: splib05a r 258 0.2-3.0µm 200 g.s.=


USA.gov logo  Take Pride in America button