DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS111

MINERAL_TYPE: Nesosilicate

MINERAL: Andradite (Garnet group)

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

FORMULA_HTML: Ca₃Fe⁺³₂(SiO₄)₃

COLLECTION_LOCALITY: Graham County, Arizona

ORIGINAL_DONOR: Wards Scientific

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Forms series with Grossular and with Schorlomite.

Under a hand lens the sample appears brown. Individual grains have varying shades of brown with an overall "salt and pepper" effect. The visible and near-IR spectrum shows spectrally pure andradite.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Andradite + Quartz - by Norma Vero

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Optical examination gives the following mineral mode:

85 vol% andradite
15 vol% Fe-stained mineral or andradite

av gr sz = 270µm

Conchoidally fractured andradite grains some of which are partially Fe-stain coated. Entire grains Fe-stained may be different phase or andradite. 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 378 0.2-3.0µm 200 g.s.= 270 µm

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

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