Our company often receive requests for treating of this type stains. The laying of floors and wall tiles in stone materials should be realized with attention to the characteristics of the stone, to the glue formula, and to the presence of humidity. An unsuitable glue, after laying could create the stains on the entire surface or on part of it. In this occasion, the stained material was a “Californian Calacatta”, in other times our staff found stains on granite and quartzite. For a correct application, it is necessary to rely to the experienced professionals and work on the installation with an epoxy resin or with suitable white glues.