Here's why:
* Intrusive Igneous Rocks: These rocks form when magma cools and solidifies beneath the Earth's surface. Since the surrounding rock acts as an insulator, the cooling process is slow. This slow cooling allows for the formation of large mineral crystals, resulting in a coarse-grained texture.
Examples of intrusive igneous rocks with coarse-grained textures include:
* Granite: A common and widely found intrusive igneous rock.
* Gabbro: A dark-colored, coarse-grained intrusive rock.
* Diorite: A medium-gray, coarse-grained intrusive rock.
In contrast:
* Extrusive Igneous Rocks: These rocks form when lava cools and solidifies on the Earth's surface. The cooling process is much faster due to exposure to the atmosphere. This rapid cooling results in smaller crystals, leading to a fine-grained texture.
