Here's why:
* Slow cooling: When magma cools slowly, the atoms have more time to arrange themselves into a regular, crystalline structure. This leads to the formation of large, visible crystals.
* Intrusive: Intrusive igneous rocks form when magma cools and solidifies beneath the Earth's surface. The surrounding rock provides insulation, slowing down the cooling process.
Some examples of intrusive igneous rocks with large crystals include:
* Granite: A very common rock with large crystals of quartz, feldspar, and mica.
* Gabbro: A dark-colored rock with crystals of pyroxene and plagioclase feldspar.
* Diorite: A medium-colored rock with crystals of hornblende, plagioclase feldspar, and quartz.
