Chromian Antigorite from the Chromite Deposit near Byrapur, Mysore State, India

Scaly aggregates of purple or lavender coloured chromian antigorite occur interlaced with carbonates, in small veins, cutting across the chromite deposit near Byrapllr chromite mines, Mysore State. The physical, optical and chemical characters of the mineral are determined. The axial angle, refractive indices and birefringence of the mineral are higher than those of the normal antigorite, due to the presencc of chromium in the mineral. X-ray and electron microscopy studies of the mineral were made by Dr. G. W. Brindley and C. R. F. De Kimpe, in the Department of Ceramic Technology, Pennsylvania State University, U.S.A. X-ray powder diagram shows that it belongs to serpentine group; electron diffraction proves that the mineral is antigorite. It contains 3.86% of Cr₂O₃.