Extensive deterioration of building stone dolomite has occurred to a high degree after restorations which included repairs with concrete and cement-lime mortars as plasters. Deteriorations have been examined on samples taken from efflorescence, decay zones of stone, and fresh interiors. Investigations were done by petrographic analysis of thin-sections, x-ray powder diffraction analysis, infrared spectroscopy, and chemical analysis. The soluble salts formed are mainly Epsomite: MgSOub>4 7Hub>2ub>Iub> ub>Oub> ub>aub>nub>dub> ub>Hub>eub>xub>aub>hub>yub>dub>rub>iub>tub>eub > :ub> ub>Mub>gub>Sub>Oub> ub>Iub>4 6Hub>2 O. The forms of dolomite deterioration and mechanisms of salt formation were tried to be explained in terms of change in the dolomite structure and dedolomitization. See also AATA 20-829.