Oxidized iron expands by 100% of its original volume. This is the phenomenon which is commonly called rust. The expanded metal exerts enormous stresses on masonry where it is embedded, causing cracks and structural failures. The process of failure is called oxide jacking. Most prominent examples of oxide jacking are at St. Paul's Cathedral and the Acropolis. The first such sign of such failure is a detectable surface stain, followed by masonry spalling and structural cracks. The rusting iron must be removed and replaced with brackets, dowels or reinforcing bars made from special metal alloys. The so-called stainless steel is not suitable because under certain circumstances it will corrode also. Reinforcement and repair can also be executed successfully with epoxy and other synthetic resins.