MINERALOGY OF INCLUSIONS IN CORUNDUM FROM THE MINE NO. 418, ILMEN STATE RESERVE, SOUTH URALS

Abstract

Corundum crystals with rims of spinel and a wide spectrum of inclusions are studied from actinolite-mica veins in altered ultramafic rocks located among metaterrigenous rocks of the Ilmeny-Vishnevogorsk polymetamorphic complex. In total, 32 minerals are identified including amesite Mg2Al(AlSiO5)(OH)4 , baddeleyite ZrO2 , gersdorffite NiAsS, dissacisite-(Ce) (CaCe)(Al2Mg)(Si2O7)(SiO4)O(OH), and nickeline NiAs, which were found for the first time in the Ilmeny Mountains. The formation of various inclusions in corundum is related to the influence of high-Al fluid enriched in alkali elements, REEs, rare metals, and Ba during tectono-metamorphic activation of the complex.

Keywords

• corundum
• sapphire
• spinel
• inclusions
• dissakisite-(ce)
• baddeleyite
• ilmeny mountains