In materials science, malleability is the ability of a material to undergo large plastic deformations under compressive stress. Compressive stress is the reverse of tensile stress. Adjacent parts of the material tend to press against each other through a typical stress plane. Material may be flattened into thin sheets if malleable by hammering or rolling. Malleable materials can be flattened into metal leaves. Many metals with high malleability also have high ductility.
Gold is the most malleable of all metals. Gold is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal. It can be drawn into a monoatomic wire and then stretched about twice before it breaks. Such nanowires distort via formation, reorientation, and migration of dislocations and crystal twins without noticeable hardening. A single gram of gold can be hammered into a gold foil of 1 square meter.