Sample Description USGS Spectral Library Version 7

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
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TITLE: Heulandite GDS3 DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: GDS3

MINERAL_TYPE: Tectosilicate

MINERAL: Heulandite (Zeolite group)

FORMULA: (Na,Ca)2-3Al3(Al,Si)2Si13O36*12H2O

FORMULA_HTML: (Na,Ca)_2-3Al₃(Al,Si)₂Si₁₃O₃₆•12H₂O

COLLECTION_LOCALITY: Poonah, India

ORIGINAL_DONOR: Wards Scientific

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

The sample appears white and to be spectrally pure.

IMAGE_OF_SAMPLE:

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Zeolites of the heulandite group
Probably a mixture of compositions; best match is clinoptilolite.

Konnert, Judith and Marta Flohr, 1992, unpublished data, USGS Reston, VA.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

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Bimodal Grain Size Distribution:
mode 1: 176 µm @ 50 vol%
mode 2: 40 µm @ 50 vol%

average grain size= 128 µm

Low relief, one good cleavage, biaxial (+), refractive index < glycerin. No contaminants, sample very clean. All this is consistent with this sample being heulandite or clinoptilolite. G. Swayze.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

The spectrum matches that of heulandite NMNH84534 very closely and is a bit more inconsistent with those of the clinoptilolites GDS2 and GDS152 in this database. Because the XRD information is not clearly indicative of this sample being clinoptilolite, based on the spectral match to heulandite NMNH84534 I think it should remain labeled heulandite. G. Swayze

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1a2a3a4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns