What Does Fracture Mean?
A fracture is an interior cleavage or a break within a metamorphic rock. It does not result from movement. A fracture at a location where the displacement of rock is involved is called a "fault." A "joint" is a fracture in which the walls of a fracture have moved only in relation to each other.
Fractures are also found in sedimentary rocks including carbonates. Carbonates, such as limestone, fracture in a distinctive rhombohedral pattern while others, such as coal – a form of carbon – fracture along a single plane. Diamonds, being carbon subjected to high geologic pressures over extended periods of time, likewise fracture along a single plane.