Acmite

Spectrum Details

Modality

NIR

Category

mineral

Material Type

Inosilicate

Sample ID

NMNH133746

Collection Locality

Kangerdluarssuk, Narssaq (near), Greenland

Spectral Purity

1a2_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 COMPOSITION KEYWORD Oxide ASCII Amount Weight Percent, % Oxide html COMPOSITION: SiO2 52.08 wt% SiO2 COMPOSITION: TiO2 0.56 wt% TiO2 COMPOSITION: Al2O3 0.98 wt% Al2O3 COMPOSITION: FeO 29.22 wt% FeO COMPOSITION: MnO 0.24 wt% MnO COMPOSITION: MgO 0.06 wt% MgO COMPOSITION: CaO 3.84 wt% CaO COMPOSITION: Na2O 11.87 wt% Na2O COMPOSITION: K2O 0.02 wt% K2O COMPOSITION: Total 98.87 wt% COMPOSITION: O=Cl,F,S wt% COMPOSITION: New Total wt%

Sample Description

This sample was obtained by John W. Salisbury, and the original sample analysis and mid-infrared spectra were published in: 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. "Original sample was large (up to 2cm), very dark green prismatic crystals of acmite intergrown with albite(?). Material was crushed and hand picked by J. Salisbury for grinding." Sieve interval is: 74-250 µm IMAGE_OF_SAMPLE:

XRD Analysis

The 74-250 µm grains were x-rayed by Norma Vergo. The resulting pattern showed acmite and an unidentified peak of trace proportions at 4.48 Angstroms. see: 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