Geological Controls of Mineralization of Corundum at Gobbagurthi, Khammam Telangana India

Industrial grade Corundum and gem variety, (ruby and abrasive variety) occurs in and around Lakshmipuram and Gobbagurti areas of Khammam District of Andhra Pradesh. The area is within the Khammam Schist Belt., which is the northern extension of the Nellore Schist Belt of the Indian Peninsular Shield. Local entrepreneurs extract corundum based on certain faiths and beliefs since a long time. The nature of occurrence of corundum in these areas represents in-situ, float, and placer concentrations. Corundum occurs along with biotite gneisses, amphibolites and sillimanite-cordierite-diopsidebearing rocks, and magnesium-aluminium rich pelitic granulites. Tonalitic gneisses, cordieritecorundum rock and sillimanite schists form small lenticular bodies. The host rocks of corundum are intruded younger pegmatite veins that also have cut through the Precambrian suite of rocks. Distinct controls of corundum mineralisation manifested in geomorphology, structure and lithology are observed in an area that have proved to be very useful guides for understanding the various controls of corundum mineralization at Gobbagurthi as well as in surrounding areas of corundum occurrences in Khammam district.