Hedenbergite

Spectrum Details

Modality

FTIR

Category

mineral

Material Type

Inosilicate

Sample ID

HS10.1B, HS10.2B, HS10.3B, HS10.4B

Collection Locality

Silver Star, Montana

Spectral Purity

1c2_3_4_ # Hedenbergite HS10.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1c2_3_4_ # Hedenbergite HS10.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1c2c3c4c # Hedenbergite HS10.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1c2_3_4_ # Hedenbergite HS10.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

Composition / XRD

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

Sample Description

Forms series with Diopside and with Johannsenite. "S-17C. Pyroxene, variety Hedenbergite. Silver Star, Montana (10B). This sample has such strong ferric and ferrous ion bands on either side of 1µ that the reflectivity of the sample is reduced throughout the first half of the near-infrared range. Very weak water bands near 1.9 and 2.3 µ indicate the presence of some fluid inclusions. By contrast, a sample of artificially prepared hedenbergite displays a single strong ferrous ion band near 1.1 µ." Hunt, G.R., J.W. Salisbury, 1970, Visible and near-infrared spectra of minerals and rocks: I. Silicate minerals. Modern Geology, v. 1, p. 283-300. Grain size fractions are indicated by the extension after the sample number: .1B = IMAGE_OF_SAMPLE:

XRD Analysis

40 kV - 30 mA, 7.3-9.5 keV File: hedbg10.mdi, *.out (smear mount on quartz plate) References: JSPDS#41-1372; Huebner's reference patterns Found: Clinopyroxene consistent with hedenbergite, minor quartz, unindexed weak to very weak reflections at 8.6, 3.16, 3.11 Angstroms Comment: Clinopyroxene pattern that is distinct from that of diopside (such as HS-15.3B). Pyroxene reflections are not sharp, suggesting poor crystallinity or compositional heterogeneity. Quartz identification originally based on four weak reflections, subsequently confirmed by optics (n=1.545). Optically, many grains are discolored by brown, heterogeneously distributed material; the actual pyroxene grains are colorless by comparison. Does the optical spectrum see the pyroxene?

X Units

cm⁻¹

Y Units

Absorbance

Data Points

1,801