In its oxide or silicate form, silicon is used to make concrete, bricks, glass, ceramics, and soap. Silicon metal is also the base material for making silicones used in such products as synthetic oils, caulks and sealers, and anti-foaming agents.
Intrusive igneous rocks crystallize below Earth's surface, and the slow cooling that occurs there allows large crystals to form. Examples of intrusive igneous rocks are diorite, gabbro, granite, pegmatite, and peridotite. Extrusive igneous rocks erupt onto the surface, where they cool quickly to form small crystals.
Igneous rocks are called fire rocks and are formed either underground or above ground. Underground, they are formed when the melted rock, called magma, deep within the earth b â¦ ecomes trapped in pockets. As these pockets of magma cool slowly underground, the magma becomes igneous rock.hen magma appears above the earth, it is called lava. Igneous rocks are formed as the lava cools above ground.     Metamorphic rocks are rocks that have morphed into another kind of rock. These rocks were once igneous or sedimentary rocks.