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USGS Spectral Library Version 7 Sample Description

Kokaly, R.F., Clark, R.N., Swayze, G.A., Livo, K.E., Hoefen, T.M., Pearson, N.C., Wise, R.A., Benzel, W.M., Lowers, H.A., Driscoll, R.L., and Klein, A.J., 2017, USGS Spectral Library Version 7: U.S. Geological Survey Data Series 1035, 61 p., https://doi.org/10.3133/ds1035
For more information on the library, see: local link web link

TITLE: Pectolite NMNH94865 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: NMNH94865.a, NMNH94865.b

MINERAL_TYPE: Inosilicate

MINERAL: Pectolite

FORMULA: NaCa2Si3O8(OH)

FORMULA_HTML: NaCa2Si3O8(OH)

COLLECTION_LOCALITY: Thetford, Ontario, Canada

ORIGINAL_DONOR: Smithsonian Institution

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Forms series with Serandite.

"Results of petrographic examination: Hand specimen consists of one small (1mm x 1cm) and one larger (5mm x 6mm x 1cm) fragment. The larger one has a large area of albite (1/4 of the sample). The rest is composed of pectolite needles. Under petrographic microscope, sample has 2% of an isotropic mineral. Fibrous nature of mineral precludes effective sieving. Fine fraction separated from coarse fraction by elutriation in acetone."

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.

Grain size fractions are indicated by the extension after the sample number:
a = 1-3 mm
b = < 1 mm

IMAGE_OF_SAMPLE:
Photo of sample

Photo is of the fine grained sample "b".

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Pure pectolite.

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.

Pure (Norma Vergo).

END_XRD_ANALYSIS.

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

COMPOSITION
KEYWORD
Oxide
ASCII
Amount Weight
Percent, %
Oxide
html
COMPOSITION: SiO2 53.37 wt% SiO2
COMPOSITION: TiO2 0.01 wt% TiO2
COMPOSITION: Al2O3 0.03 wt% Al2O3
COMPOSITION: FeO 0.11 wt% FeO
COMPOSITION: MnO 0.03 wt% MnO
COMPOSITION: MgO 0.03 wt% MgO
COMPOSITION: CaO 33.84 wt% CaO
COMPOSITION: Na2O 9.61 wt% Na2O
COMPOSITION: K2O 0.01 wt% K2O
COMPOSITION: Total 94.04 wt%

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

Microprobe analysis found the sample homogeneous within and between grains of pectolite. Average of 8 samples.

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.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Sample "a" consists of elongate grains ~ 1 to 5 mm in length whereas sample "b" consists of ~ 0.1 to 1mm elongate grains. G. Swayze.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2b3b4_ # NMNH94865.a # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns
SPECTRAL_PURITY: 1b2b3b4b # NMNH94865.b # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns