DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: WS484

MINERAL_TYPE: Nesosilicate

MINERAL: Grossular (Grossularite)(Garnet group)

FORMULA: Ca3Al2(SiO4)3

FORMULA_HTML: Ca₃Al₂(SiO₄)₃

COLLECTION_LOCALITY: Asbestos, Quebec

ORIGINAL_DONOR: Wards Natural Science Inc.

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Labortory

SAMPLE_DESCRIPTION:

Forms series with Andradite, with Hydrogrossular, with Uvarovite.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 6.5-9.5 keV
File: gros484.out, *.mdi
References: Borg and Smith (1969), JCPDS #39-368, DHZ, v. 1a(1982), Huebner's reference patterns
Found: Garnet

Comment: Well crystallized reflections indicate good crystallinity and suggest chenical homogeneity. The garnet has ao=11.81 angstroms, consistent with grossular-rich composition.

END_XRD_ANALYSIS.

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

COMPOSITION:	SiO2	39.710	wt%	SiO2
COMPOSITION:	TiO2	.253	wt%	TiO2
COMPOSITION:	Al2O3	22.580	wt%	Al2O3
COMPOSITION:	Cr2O3	.006	wt%	Cr2O3
COMPOSITION:	V2O3	.016	wt%	V2O3
COMPOSITION:	FeO	1.769	wt%	FeO
COMPOSITION:	NiO	.017	wt%	NiO
COMPOSITION:	MnO	.690	wt%	MnO
COMPOSITION:	MgO	.019	wt%	MgO
COMPOSITION:	CaO	36.170	wt%	CaO
COMPOSITION:	Total	101.230	wt%
COMPOSITION:	O=Cl,F,S		wt%	#correction for Cl, F, S

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Bimodal grain size distribution:
mode 1: 240 µm @ 75 vol%
mode 2: 15 µm @ 25 vol%

av gr sz = 210 µm

Trace iron staining. Grains isotropic, with parting, refractive index > glycerin. All consistent with this sample being pure garnet. 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 1868 0.2-3.0µm 200 g.s.= 210 µm

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

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