Natural intensity, susceptibility, and Kocnigsbarger ratio w0re determined and studies of R.ayloigh loops, and high field hysteresis, and variation of susceptibility with temperature from-196~ to Curio temperature w~re made on a number of magnetite-quartzitG and pyroxene granulite sampl.-s from Tamil Nadu. Fee, Fete3, and Ties proportions were estimated and cell dim~aasions were determined. Frcm the magnetic studies it is infcrr~l that in general the samples contam predornirtantty multidomain grains. In a few cases single-domain l~artieles are detected, while in a few other samples a mixture of supcrparamagnctic partiel~ and single domain states could be inferred. Tho rdativc rmrmnmaec ratio is found to increase with coercive force. The ferromagnetic rninoral in magnotito-quartzites is pure magnetite with a little alteration to b~m~tite while in pyroxene granulit~s it is a tita~iferous magnetite with a small percentage of TiOz. It is probable that the cell dimensions are dependent on oxidation in magnetites, and on the content of TiOz in titanfferous magnetites.