Abstract
Feldspar minerals can be used as naturally occurring radiation dosemeters, with dose assessment commonly using luminescence techniques. Since many feldspars contain radioactive K-40, knowledge of the mineralogy of the luminescent samples being measured is of high importance. Most feldspars contain more than trace amounts of highly luminescent Fe3+ impurities, and this article examines the relationship between features of the luminescence excitation spectrum of this ion with sample mineralogy. It is demonstrated that there is a near linear correspondence between the plagioclase feldspar composition and the separation of the T-4(2)(D) and (4)A(1)(4)E(G) Fe3+ ion levels, and this could be used to identify plagioclase feldspar composition. In the samples tested, certain features of the spectra also allowed a distinction to be made between the alkali (K-Na) and plagioclase (Na-Ca) feldspar groups. The results are compared with properties of the excitation spectra dose-dependent optically stimulated luminescence (OSL) in order to compare the chemical environment of the OSL donor defect, and the isolated Fe3+ centres.
Original language | English |
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Journal | Radiation Measurements |
Volume | 26 |
Issue number | 1 |
Pages (from-to) | 93-101 |
ISSN | 1350-4487 |
DOIs | |
Publication status | Published - 1996 |