U.S. Geological Survey home page

USGS Spectral Library Version 7 Sample Description

Kokaly, R.F., Clark, R.N., Swayze, G.A., Livo, K.E., Hoefen, T.M., Pearson, N.C., Wise, R.A., Benzel, W.M., Lowers, H.A., Driscoll, R.L., and Klein, A.J., 2017, USGS Spectral Library Version 7: U.S. Geological Survey Data Series 1035, 61 p., https://doi.org/10.3133/ds1035
For more information on the library, see: local link web link

TITLE: Andradite WS474 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: WS474

MINERAL_TYPE: Nesosilicate

MINERAL: Andradite (Garnet group)

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

FORMULA_HTML: Ca3Fe+32(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.

IMAGE_OF_SAMPLE:
Photo of sample

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: EPMA # XRF, EPMA, 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