О ЛЮМИНЕСЦЕНЦИИ ЕU2+ В ПОЛЕВЫХ ШПАТАХ МУСКОВИТОВЫХ ПЕГМАТИТОВ

Abstract

Data of photoluminescence (PhL), precisely fixing Eu2+ centers, and X-ray luminescence (XrL) were compared for plagioclases and potassium feldspars in 21 samples from muscovite pegmatites of Mamsky region. Content of europium was defined in 10 samples. It has been revealed that Eu concentrations in feldspars vary froml(r4tol(r6wt%, i. e. n ■ (1.0-0.1) ppm. The element is present there, mainly in bivalency form, due to its geochemical alliance with Sr2*, Ca2+ and Ba2+- Eu2+ replaces them isomorphousely. Eu was accumulated in the early products of crystallization, and along the process of pegmatites formation its amount decreases by the order down to the complete absence in the late generations of feldspars. It is shown that in X-ray luminescence spectra of feldspars Eu2t may be identified and its relative concentration may be also determined qualitatively: for instance, in plagioclases by presence and intensity of the radiation band Xai - 400-420 nm.