Bentonite in Kutch District, Gujarat State, India where Mahavir Minerals is presently operating, occurs in Supra Trappean formation of lower Eocene period that lies over trap formation
It generally lies between Laterite and basalt belt. It occurs below an overburden of 1 to 8 meters thick and extends downwards to adepth of 10 to 12 meters. Field evidence shows that Basalt has been geo-chemically weathered in-situ dominantly into clays of different composition. Basaltic rocks containing calcium, magnesium tend to weather in to montmorillonite, the predominant clay of Bentonite. Bentonite is a grit free soft material and the lump colours are pale yellow, light green, dark green or light brown depending upon surrounding conditions at the time of formation. Bentonite is classified into two types on the basis of ratio of exchangeable calcium and sodium ions.