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Clark et. al. 2003 USGS Open File Report 03-395
Spectral Library splib05a Sample Description

(For further information on spectrsocopy, see: http://speclab.cr.usgs.gov)

TITLE: Stilbite HS482 Zeolite DESCRIPT

DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS482

MINERAL_TYPE: Tectosilicate

MINERAL: Stilbite (Zeolite Group)

FORMULA: NaCa2Al5Si13O36*14H2O

FORMULA_HTML: NaCa2Al5Si13O36•14H2O

COLLECTION_LOCALITY: Nova Scotia

ORIGINAL_DONOR: Hunt and Salisbury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

A spectrum for this sample was published in: Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1973, Visible and near-infrared spectra of minerals and rocks: VI. Additional silicates. Modern Geology, v. 4, p. 85-106.

With the note: "The major water features occur at 0.985, 1.17, 1.44, 1.92µm and the bands are generally broad and not well resolved. The reflectivities for sizes I through IV are 98, 91, 79, and 62% at 1.1µm.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

40 kV- 30 mA, 6.5-9.5 keV
File: stilb482.mdi
References: Tschernich (1992); PDF2 #24-0894, 25-0124, 26-584, 29-1185, 41-1356, 41-1357, 44-1479; Akizuki and Konno (1985)
Found: Barrierite, stellerite, or stilbite

Comments: Sharp peaks but poorly resolved alpha1-alpha2 reflections are consistent with some variation in composition or structural order. The pattern was indexed by comparison with PDF2 #26-0584 (stilbite, calculated by D. Smith et al., 1970). A moderately weak shoulder on the larger d-spacing side of the (020) is the only unexplained feature. Line-base search-match returns barrierite, stellerite, and stibite; profile-based search-match returns only barrierite. These three species are so closely related that they might all better be considered stilbite (Tschernich, 1992). Visual comparison of overlaid patterns indicates that barrierite (29-1185), stellerite (25-0124), and stilbite (44-1479)are each an excellent match for HS-482. Another stilbite (24-0894) and structurally related heulandite and brewsterite are poor matches and were eliminated as possibilities.

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: # XRF, EM(WDS), ICP(Trace), WChem

COMPOSITION_TRACE:

COMPOSITION_DISCUSSION:

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment
LIB_SPECTRA: splib04a r 4635 0.2-3.0µm 200 g.s.=
LIB_SPECTRA: splib05a r 6426 0.2-3.0µm 200 g.s.=


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