Fedorite in Charoite and Brookite-Feldspar-Quartz Rocks of the Alkaline Murun Complex

The paper presents the mineralogical-petrographic study of fedorite from three locations of the Murun complex: Irkutskiy and Yakutskiy districts and Gavrilovskaya zone. Two different mineral associations were discovered. The first one is associated with charoite mineralization (Irkutskiy and Yakutskiy district), while the second one from the Gavrilovskaya zone is associated with brookite-feldspar-quartz rocks. The morphogenetic features of fedorite, its paragenetic associations were studied using an Olympus BX-51 polarizing microscope in transmitted and reflected light. The investigation of the form of occurrence of minerals and their relationship made it possible to determine the sequence of the crystallization of minerals in the studied associations. In addition, some differences are noted in the chemical composition of fedorite, both between the studied samples and with previously published data.