Hardness and Brittleness seem to be totally different things.
Hardness refers to various properties of matter in the solid phase that give it high resistance to various kinds of shape change when force is applied.
Hard matter is contrasted with
soft matter.
A
material is
brittle if it is liable to
fracture when subjected to
stress. That is, it has little tendency to deform (or
strain) before fracture. This fracture absorbs relatively little
energy, even in materials of high
strength, and usually makes a snapping sound.
