Granite is one of the most common rocks on our planet. It is an igneous rock that was formed from hot, melted rock called magma. The hot, liquid rock is called magma while it remains underground and is called lava when it comes out of the earth's crust during a volcanic eruption. The hot magma cools underground and hardens into solid rock. Granite is made up mostly from a mixture of quartz, feldspar and mica crystals. It has large crystals that you can see very easily. The black specks that you can see in the picture are crystals of mica.