Abstract: A composite material system having an aggregate bound by an elastomer encapsulant. The composite material (CM) is designed to defeat impinging projectiles by converting the kinetic energy (KE) in the projectile to damage in the aggregate and the elastomer and increasing the thermal energy in the CM and the projectile via frictional heating. In one embodiment, the CM comprises certain kinds of rocks encapsulated (or bound) in a hyper-elastic polymer, such as polyurethane (“PU”). The CM may be shaped into convenient shapes from modular assembly to create a ballistic resistant surface.