High temperature sealing material

Glass composition for use as sealing material in fuel cells, comprising a glass matrix with main components consisting of SiO2, Al2O3, and one or more compounds from group I metal oxides and/or group II metal oxides, and a filler material evenly dispersed in the matrix, wherein the filler material consists of particles of one or more refractive compounds from the group : MgO—MgAl2O4, stabilized zirconia, rare earth oxides, (Mg, Ca)SiO3, Mg2SiO4, MgSiO3, CaSiO3, CaZrO3, ThO2, TiO2, MIIAlSi2O8, where MII=Ca, Sr or Ba.