This statement is actually false because is actually porous because rock is porous and non-permeable.
Pores are not connected to each other. Even though water can enter pores (rock is porous), it cannot move through the rock layer (impermeable).
However, some rocks have high porosity and high permeability and also have medium and low permeability and porosity.
Examples:
- GRAVEL: high porosity; high permeability.
- FRACTURED GRANITE: low porosity: very high permeability.
Hope so, this answer will help you......