Skip to main content
U.S. flag

An official website of the United States government

Reflecting curved-crystal X-ray spectrograph; a device for the analysis of small mineral samples

November 12, 1956

A curved-crystal reflecting spectrometer of the type described by Birks and Brooks of the Naval Research Laboratories, but adapted for use in mineralogical studies, has been built in the Geological Survey. It has been successfully applied to the analysis of tiny crystals, zones in minerals, and individual grains in mixed-mineral specimens such as thin or polished sections, on grains or areas about 0.5 mm in diameter, X-ray diffraction spindles, and small samples of powder weighing a fraction of a milligram have also been analyzed without any loss or alteration of the sample. Of great value in thin- and polished-section work is the fact that this technique can be used to analyze selected areas without mutilating the specimen by digging out grains.A modification of the curved-crystal spectrometer has made it possible to traverse a standard polished section in synchronization with a recorder, automatically plotting the distribution of various elements along a selected line. This method was applied, for example, to a polished section containing a central core of pyrite intergrown with and surrounded by a marcasite-like mineral. Chemical analysis of a concentrate of these two minerals gave selenium, cobalt, and iron as major constituents. A clear relationship between the cobalt, selenium, and iron was established by the X-ray method, identifying the second mineral as an intermediate member of the FeSe 2 -CoSe 2 series.

Citation Information

Publication Year 1956
Title Reflecting curved-crystal X-ray spectrograph; a device for the analysis of small mineral samples
DOI 10.2113/gsecongeo.52.6.694
Authors I. Adler, J. M. Axelrod
Publication Type Article
Publication Subtype Journal Article
Series Title Economic Geology
Series Number
Index ID 70216345
Record Source USGS Publications Warehouse
USGS Organization