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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: Pigeonite HS199 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS199

MINERAL_TYPE: Inosilicate

MINERAL: Pigeonite (Pyroxene group)

FORMULA: (Mg,Fe+2,Ca)(Mg,Fe+2)Si2O6

FORMULA_HTML: (Mg,Fe+2,Ca)(Mg,Fe+2)Si2O6

COLLECTION_LOCALITY: Loudoun County, Virginia

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

I-6 Pigeonite 199B-Londoun Co., Va. (Mg, Fe2+, Ca) (Mg, Fe2+) (Si2O6): This mineral is common in igneous rocks of the extrusive volcanic type, particularly in andesites and dacites. Its spectrum is quite flat with a broad feature at 0.95µ, typical of six-fold coordinated ferrous iron.

Sieve interval 74 - 250µm.

Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1973, Visible and near-infrared spectra of minerals and rocks: VI. Additional silicates. Modern Geology, v. 4, p. 85-106.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV - 30 mA, 7.3-9.5 keV
File: pignt199.out, -.mdi (smear mount on quartz plate)
References: Borg and Smith (1969); Huebner's reference patterns.
Found: high albite, clinopyroxene, minor quartz, many weak unidentified reflections, including a possible ilmenite (211)

Comment: Sharp reflections suggest good crystallinity and compositional heterogeneity. Quartz has some unusual relative intensities, perhaps because the amount present is insufficient to give a random distribution of grain (lattice) orientations. The clinopyroxene pattern is very similar to that obtained from a lunar augite-pigeonite intergrowth; in neither case were two clinopyroxenes resolved in the powder pattern.

J.S. Huebner, J. Pickrell, T. Schaefer, written communication(USGS)

END_XRD_ANALYSIS.

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


COMPOSITION
KEYWORD
Oxide
ASCII
Amount Weight
Percent, %
Oxide
html
COMPOSITION: FeO 25.31 wt% FeO
COMPOSITION: MnO 40.86 wt% MnO
COMPOSITION: CaO 33.93 wt% CaO
COMPOSITION: Total wt%
COMPOSITION: O=Cl,F,S wt% #correction for Cl, F, S
COMPOSITION: New Total 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 3906 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 5438 0.2-3.0µm 200 g.s.=


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