Pyroxene

Spectrum Details

Modality

FTIR

Category

mineral

Material Type

Inosilicate

Sample ID

HS119.1B, HS119.2B, HS119.3B, HS119.4B

Collection Locality

Oaxaca, Mexico

Spectral Purity

1c2_3_4_ # HS119.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1c2_3_4_ # HS119.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1c2c3c4c # HS119.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1c2_3_4_ # HS119.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

Composition / XRD

None # XRF, EPMA, ICP(Trace), WChem COMPOSITION_TRACE:

Sample Description

"I-4 Augite 119B-Oaxaca, Mexico. (Ca, Mg, Fe^2+, Fe^3+, Ti, Al)2(Si, Al)2O6: Augite is an important ferromagnesian mineral of igneous rocks, and is particularly common in basic rocks. It occurs, but less frequently, in intermediate and ultrabasic rocks. The spectrum is dominated by both Fe^2+ and Fe^3+ absorptions, which produce a very general broad band centered near 1.0µ. The faint bands near 2.3µ are probably due to hydroxyl combinations even though the 1.4µ band is indiscernible." 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. Grain size fractions are indicated by the extension after the sample number: .1B = IMAGE_OF_SAMPLE:

XRD Analysis

40 kV - 30 mA, 7.0-9.5 keV File: Pxn119.out, -.mdi References: Borg and Smith (1969); Huebner's reference patterns Found: Clinopyroxene; weak reflections at 6.5 and 3.14 Angstroms; possibly significant intensity maxima at 9.4 and 8.4 Angstroms. Comment: Well crystallized pyroxene. Excellent overall match with diopside patterns, but the lattice spacings are slightly larger than in HS15.3B or endmember diopside, suggesting solid solution with hedenbergite. The relatively high background is consistent with secondary radiation due to iron. The two weak reflections are in the positions of plagioclase unindexed reflections that do not correlate with any of the pyrrhotite polytypes suggesting an additional phase red orientation? J.S.Huebner, J. Pickrell, T. Schaefer, written communication(USGS 1994) Augite(Major),Ferropargasite(trace),Ferrohornblende(trace) Sutley April, 2005.

X Units

cm⁻¹

Y Units

Absorbance

Data Points

1,801