Griffith Crack

A Griffith Crack is a mechanism to explain how rocks, which can be very strong materials, are fractured by stress in the crust.  Microscopic cracks in the rock, which can be the result of a flaw or inclusion in a mineral, will concentrate the tensile stress in a rock.  This can lead to the expansion (or propagation) of the crack and even to failure of the rock resulting in a fault.