Talc-bearing rocks in Kallievo-Murennanvaara deposit are associated with ultramafic rocks of peridotite-picritic series. Serpentinized rocks in the picritic portion of the sequence remained unaffected by talc alteration. Peidotitic komatiites, occurring below picrites which were altered to talc-carbonate rocks by carbon dioxide and then to talc-chloritic rocks under the influence of silica and alumina (the result of granite formation), were productive for soapstone. Kallievo-Murennanvaara soapstone deposit, is located on the south shore of Lake Segozero in the Medvezhyegorsk District, Republic of Karelia. Talc-bearing rocks are 40-65 m thick and 450 m long. They were used as raw materials in the radio industry and electrical technology and as refractory and facing material with an emphasis on a monolithic variety. The conditions of formation, mineral and chemical composition, thermal physical properties and possible applications of Kallievo-Murennanvaara talc-bearing rocks are discussed below.