The ophiolitic rocks appearing near Monte Chiaro, characterized by serpentine masses crossed by veins of talc, sometimes of remarkable thickness, are to be found on the right of the Taro river a few miles from Borgotaro. On examination three interstratified clay minerals were found: saponite-talc, chlorite-saponite, chlorite-vermiculite, which were studied optically, with X-ray, d.t.a. and chemical analysis.