You will learn about "3 Types of Rocks" in this video. Rocks can be broadly divided into three types on the bases of their formation, namely igneous rocks, sedimentary rocks and metamorphic rocks. Igneous rocks are formed from magma, which is a molten rock found deep inside the earth. This molten magma comes upwards or even erupts from a volcano in the form of lava. When this molten magma cools, it leads to the formation of igneous rocks. Some examples of igneous rocks are granite and pumice.