Igneous Rock: Face of the Earth. On the earth's surface, there are three types of rocks, metamorphic, sedimentary, and igneous. In northern Canada, much of the hard rock found is igneous rock. Igneous rock is rock formed by the hardening and crystallization of molten material that originates deep within the earth.
Igneous rocks form from the solidification of magma (molten rock). A reminder: magma is molten rock beneath the Earth's surface and lava is magma that is on the Earth's surface. The main characteristics of an Igneous rock are crystal size (grain size) and texture.
Extrusive igneous rocks, also known as volcanic rocks, are formed at the crust's surface as a result of the partial melting of rocks within the mantle and crust. Extrusive igneous rocks cool and solidify quicker than intrusive igneous rocks. They are formed by the cooling of molten magma on the earth's surface.