DOCUMENTATION_FORMAT: MINERAL

SAMPLE_ID: HS168

MINERAL_TYPE: Tectosilicate

MINERAL: Natrolite + Zeolites (Zeolite group)

FORMULA: Na2Al2Si3O10*2H20

FORMULA_HTML: Na₂Al₂Si₃O₁₀•2H₂O

COLLECTION_LOCALITY: Springfield, Oregon

ORIGINAL_DONOR: Hunt and Salibury Collection

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Dimorphous with Tetranatrolite.

"T-21 Natrolite 168B--Springfield, Ore. Na₂Al₂- Si₃O₁₀.2H₂O: This zeolite occurs in cavities in basalts and related rocks and also as an alteration product of nepheline, sodalite or plagioclase. Its major features occur at 0.85µ, 1.165µ, 1.44µ, and 1.95µ. These bands are considerably sharper than in the stilbite."

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.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Natrolite + lg. amount of analcime + sm. amount of clinoptilolite + lg. amount other. (Norma Vergo)

Spectrally contaminated by other zeolites. (Norma Vergo)

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: None # XRF, EM(WDS), ICP(Trace), WChem

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

mode:

40 vol% Natrolite
30 vol% Analcime (isotropic, low relief, concoidal fracture)
20 vol% Clinoptilolite
10 vol% Calcite
tr Fe-oxide scale

Not many gas or fluid inclusions in natrolite. Straight extinction, prismatic habit, length slow, all properties consistent with natrolite. Clear conchoidally fractured grains have low relief, 1st order gray (nearly isotropic), undulose extinction, and rutile inclusions, and are probably analcime grains. Flat blades with length slow character are probably Clinoptilolite. Calcite fizzes in HCl. This sample is very contaminated in a modal sense. G. Swayze.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1_2_3_4_

LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment

LIB_SPECTRA: splib04a r 3418 0.2-3.0µm 200 g.s.= 180 µm

LIB_SPECTRA: splib05a r ____ 0.2-3.0µm 200 g.s.=

LIB_SPECTRA: splib06a r ____ 1.5-25µm 250 g.s.=