To ensure a clean break along the natural fracture plane, one finger is placed on the basal cheliped joint.

In lizards, fracture planes are present within the vertebrae of the tail that allow for its removal.

Strangely, the fracture planes pass through the middle of the vertebrae and not in the spaces between them.

Light danced: on the fracture planes crossing the spines, and from lines of cleavage within the central mass.

The patterns they formed resembled the fracture planes of the crystal.

Here the faults were like fracture planes snapped off in midair.

The sides of boulders are roughly planar, suggesting that some surfaces may be original fracture planes.

Orientations - the boulders may be close enough that original fracture planes can be matched.

Here's how they do it: The tail has a "fracture plane," a sort of weak spot where it can break off when grabbed.

Joe's finger moved over the line of the fracture plane.