* Formation: Diorite is an intrusive igneous rock, meaning it forms from magma that cools and solidifies *below* the Earth's surface.

* Slow Cooling: Magma deep underground cools very slowly. This slow cooling allows the minerals within the magma to crystallize and grow into larger, visible crystals.

* Texture: Diorite is characterized by its phaneritic texture, which means the crystals are large enough to be seen with the naked eye. This is a direct result of the slow cooling process.

In contrast, extrusive igneous rocks, like basalt, cool quickly on the Earth's surface. This rapid cooling results in very small crystals, giving them a fine-grained texture.