Here's why:

* Magma: Molten rock found beneath the Earth's surface.

* Intrusive: This refers to rocks that form when magma cools and solidifies *inside* the Earth's crust.

Examples of intrusive igneous rocks:

* Granite: A very common and durable rock, often used in construction.

* Gabbro: A dark-colored, coarse-grained rock.

* Diorite: A medium-grained rock with a mix of light and dark minerals.

Key characteristics of intrusive igneous rocks:

* Large crystals: They have more time to cool slowly, allowing larger mineral crystals to form.

* Coarse-grained texture: The individual crystals are visible to the naked eye.

* Often have a massive appearance: They don't have a layered structure like some other rocks.

Let me know if you'd like to learn more about intrusive igneous rocks or other types of rocks!