Augite

Spectrum Details

Modality

NIR

Category

mineral

Material Type

Inosilicate

Sample ID

NMNH120049

Collection Locality

Rozier (nr.), Gorges du Tarn, Tarn, France

Spectral Purity

1b2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

Composition / XRD

EPMA # XRF, EPMA, ICP(Trace), WChem

Sample Description

Diopside and hedenbergite form a complete solid solution series with physical and optical properties varying linearly with composition. Augite is a clinopyroxene in which some Na substitutes for Ca, some Al substitutes for both Mg (or Fe) and Si, and in which Fe and Mg contents are higher than in diopside or hedenbergite. "Results of petrographic examination: One 22.31g. piece, black, probably part of one crystal; some veining with lighter mineral (serpentine?) difficult to remove. Microscopic examination of hand-picked sample indicates about 1-2% contamination by low-index, iron stained mineral. Cleavage is virtually nonexistent, however, index of refraction and 2V point to augite." Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263. IMAGE_OF_SAMPLE:

XRD Analysis

Augite + dolomite (m). (Norma Vergo) Sample is augite plus a moderate amount of dolomite. Sample subsequently treated with warm HCl to remove dolomite. Salisbury, J. W., Walter, L. W., and Vergo, N., 1987, Mid-Infrared (2.1-25µm) Spectra of Minerals: First Edition, U.S. Geological Survey Open File Report 87-263.

X Units

cm⁻¹

Y Units

Absorbance

Data Points

2,126