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Spectral Parameter Tables for Expanded Vermiculite Samples

Metadata Updated: October 29, 2023

This dataset contains spectral parameters for absorption features found in reflectance spectra of expanded vermiculite samples. These data are provide for 52 samples of vermiculite attic insulation, horticultural products, aggregate, and packing materials derived from mines near Enoree, South Carolina; Libby, Montana; Louisa, Virginia; Palabora, South Africa; and Jiangsu, China collected from 2000 to 2016. Also included are two tables listing the spectral parameters for reflectance spectra of four expanded vermiculite samples selected to represent each of the four main historical sources of vermiculite (e.g., Libby, Montana; Enoree, South Carolina; Louisa, Virginia; and Palabora, South Africa) taken at normal spectral resolution (11 to 12 nm full width half maxiumum) and finer resolution (6nm fwhm). A third table lists the spectral parameters of spectra convolved to 11 to 12nm fwhm from the original 6nm fwhm data. Spectral parameters such as band depth were calculated by dividing the reflectance value of each spectral channel in an absorption by the corresponding reflectance value of a continuum drawn between endpoints on the shoulders of the absorption. The minimum channel of the continuum-removed data is found between the continuum endpoints, and a parabola is statistically fit to it and the two channels nearest to this minimum. The reflectance of the parabola’s center wavelength is determined, and then subtracted from 1.00 to derive the band depth of the absorption. Columns M and N list the x and y values of the contaminant non-detect line whose position passes through those samples that contain only minor to trace levels of contaminants in their sink fractions or have no Scanning Electron Microscopic evidence of contaminants (e.g., talc, amphibole, or serpentine).

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Metadata Created Date June 1, 2023
Metadata Updated Date October 29, 2023

Metadata Source

Harvested from DOI EDI

Additional Metadata

Resource Type Dataset
Metadata Created Date June 1, 2023
Metadata Updated Date October 29, 2023
Publisher U.S. Geological Survey
Identifier USGS:58797da0e4b0847d353f404d
Data Last Modified 20200929
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context
Metadata Catalog ID
Schema Version
Catalog Describedby
Harvest Object Id 92421a54-9ab8-43b1-b2dc-eb2c38f2e090
Harvest Source Id 52bfcc16-6e15-478f-809a-b1bc76f1aeda
Harvest Source Title DOI EDI
Metadata Type geospatial
Old Spatial -128.7597656235,23.684373489276,-62.490234376141,49.922653763102
Publisher Hierarchy White House > U.S. Department of the Interior > U.S. Geological Survey
Source Datajson Identifier True
Source Hash e85b03e645fe2ab3b2af6ede314d401ce0312b2a4a5667f452a96804ad160c4f
Source Schema Version 1.1
Spatial {"type": "Polygon", "coordinates": -128.7597656235, 23.684373489276, -128.7597656235, 49.922653763102, -62.490234376141, 49.922653763102, -62.490234376141, 23.684373489276, -128.7597656235, 23.684373489276}

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