Here's why:

* Foliation refers to the layered or banded appearance in metamorphic rocks caused by pressure and heat. This alignment of minerals gives the rock a distinct texture.

* Gabbro is an intrusive igneous rock, meaning it cools slowly underground. This slow cooling allows for the formation of large crystals, but it doesn't create the pressure needed for foliation.

Instead of foliation, gabbro has a phaneritic texture, meaning its crystals are large enough to be seen with the naked eye.