Abstract. Rare small intergrowths of pneumatolitic PGM (geversite, sperrylite; insizvaite, niggliite, zvyagintsevite…) and Tl–Fe–Cu sulphide are developed in little nests of magmatogenic troilite, pentlandite, cubanite, chalcopyrite and Cl-bearing phlogopite in plagioclase lherzolites from the lower part of hyperbasic-basic Ioko-Dovyrenski intrusive. The composition of the sulfide corresponds to Ni-less cupreous thalfenisite, wt.%: Tl 34.94; Ag 0.13; Fe 24.05; Co 0.18; Cu 15.95; Cd 0.19; S 22,64; Cl 0.87; sum – O = Cl2 98.75 %. The formula of the mineral is: (Tl6.24Ag0.04)6.28(Fe15.32Cu9.16Co0.14Cd0.06)25/05S25.77Cl0.89], ~ Tl6(Fe,Cu)25S26Cl. Obviously, wide variations of Fe-Ni-Cu contents is typical both for thalfenisite and its K-bearing analogue djerfisherite.