Verkhne-Mangirtuiskii

This is a small intrusion situated within early Proterozoic gneisses and crystalline schists. It is formed by peralkaline granites that have a fine-grained texture and clearly expressed orientation of the rock-forming minerals. Widely developed pegmatites lie parallel to the general fabric and, less frequently, cross-cut it; they range in thickness from several centimetres to 0.5 m. The granites are allotriomorphic, homogeneous rocks composed of coarse (2-5 mm) prismatic, and less frequently isometric, perthite or antiperthite(Or44-61), quartz (20-24%), plagioclase (5-10%; An13-17) and up to 3% aegirine-salite (40-68% of the aegirine molecule) and katophorite. Accessory minerals are magnetite, titanite, apatite, zircon and orthite.