Dumortierite

Spectrum Details

Modality

FTIR

Category

mineral

Material Type

Nesosilicate

Sample ID

HS190.3B

Collection Locality

Pershing, County, NV

Spectral Purity

1c2c3d4d # 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

"Strong absorption feature near 0.5µm is due to pi-pi transition in the boron-oxygen triangle. OH bands occur at 1.4, 2.2 and 2.6 µm." 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: .3B = 74-250 µm IMAGE_OF_SAMPLE:

XRD Analysis

40 kV - 30 mA,6.5 -9.5 keV File: dumor190_mdi, *.out; dumr190b_mdi, *.out (smear mounts on quartz plates) References: Huebner's reference patterns; Borg and Smith (1969); JCPDS #7-71 Found: Quartz, minor dumortierite, minor additional phase(s) Comment: Sharp peaks suggest high degree of crystallinity and compositional heterogeneity. The dumortierite pattern agrees well with that of hand-picked acicular lavender material from south of Alpine, San Diego County, CA (from the S. S. Huebner collection). HS190.3B shows reflections that are present in the pattern of the Alpine reference material but do not appear in the list of peaks calculated by Borg and Smith. We have not identified the reflections at 9.2, 5.57, 5.01, 4.53, 3.93, 3.53, 3.50, 2.776, 2.002, and 1.488 Angstroms J.S.Huebner, J. Pickrell, T.Schaefer, written communication (1994 USGS)

X Units

cm⁻¹

Y Units

Absorbance

Data Points

1,801