 To date a large range of bacterial strains or communities from diverse genera have been reported to be able to colonize mineral surfaces or to weather minerals, and for some of them a plant growth promoting effect was demonstrated.The demonstrated or hypothesised mechanisms used by bacteria to weather minerals include several oxidoreduction and dissolution reactions as well as the production of weathering agents, such as protons, organic acids and chelating molecules.Buildings made of any stone, brick or concrete are susceptible to the same weathering agents as any exposed rock surface.