Granites usually have a coarse texture (individual minerals are visible without magnification), because the magma cools slowly underground, allowing larger crystal growth. Granites are most easily characterized as light colored and coarse grained as a result of cooling slowly below the surface.

Why do large crystals form in granite?

The molten layer of the earth's crust (magma) was forced upward, cooling slowly beneath the metamorphic rock to form granite (a type of igneous rock). This slow cooling gives granite its typical large crystals which are visible to the naked eye.

Why would granite have larger crystals than igneous rocks?

Why do granite have large crystals? Granite in the Continental Crust The large mineral crystals in granite are evidence that it cooled slowly from molten rock material. That slow cooling had to have occurred beneath Earth's surface and required a long period of time to occur.