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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: Erionite+Offretite GDS72 DESCRIPT

DOCUMENTATION_FORMAT: MIXTURE

SAMPLE_ID: GDS72

MIXTURE_TYPE: Intimate

MIXTURE: Erionite + Offretite (Zeolite group)

FORMULA: (K2Na2Ca,Mg)2[Al4Si14O36]·15H2O + (K2,Ca)5[(Al10Si26)O72]·30H2O

FORMULA_HTML: (K2Na2Ca,Mg)2[Al4Si14O36]·15H2O and (K2,Ca)5[(Al10Si26)O72·30H2O

COLLECTION_LOCALITY: Durkee, Oregon

ORIGINAL_DONOR: Unknown

CURRENT_SAMPLE_LOCATION: USGS Spectroscopy sample collection library - Denver, Colorado

ULTIMATE_SAMPLE_LOCATION: USGS Spectroscopy sample collection library - Denver, Colorado

SAMPLE_DESCRIPTION:

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Offretite - major component
Erionite - major component
No other identifiable components

Konnert, Judith and Marta Flohr, 1992, unpublished data, USGS Reston, VA.

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: NONE # XRF, EPMA, ICP(Trace),WChem

COMPOSITION_TRACE: None

None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

mode:
95 vol% zeolite
5 vol% contaminant (high birefringence, uniaxial mineral not included in grain size estimate)

avg. grain size = < 5 µm

Elongate prismatic grains (similar to prisms with pyramid terminations) have a very low refractive index. Fine grain size limits other optical determinations, but crystal habit and refractive index are consistent with this sample being a zeolite. G. Swayze.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2b3b4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns