These rocks are not stratified. They possess crystalline and compact grains. They cannot be split into a thin slab. Granite, trap, marble etc. are the examples of this type of rocks.
Stratified Rocks:
These rocks have a layered structure. They possess planes of stratification or cleavage. They can be easily split along these planes. Sandstones, limestones, slate etc. are the examples of this class of stones.