What Is Granite?
Granite is a common type of igneous rock. Igneous rocks are formed when magma is cooled underground creating a plutonic rock. This rock is extremely durable and hard, making it the perfect substance for construction uses in such items as countertops or flooring.
How It Is Formed
Granite is formed underground by the cooling of magma. Deep within the earth, beyond the mantle layer, lies a deep layer of molten rock. The molten rock is formed when the naturally occurring radioactive elements within the ground break down and decay. The reaction of the decaying material releases large amounts of heat, melting the rocks around it. As geological events happen (such as the moving of plates or the buildup of pressure from the heat), the molten rocks are pushed toward the surface. As the rock gets closer to the surface, it also cools, creating internal igneous rocks. One of these such rocks is granite. Granite can be a mixture of mainly quartz and feldspar but also may contain mica.
How It Is Extracted
Granite usually occurs in large deposits, many times referred to as slabs, throughout the world. Mining operations use different methods of cutting to extract the different deposits from the ground in places called quarries. These slabs are then polished, put on trucks and sent to fabricators. The fabricators will then cut the slabs into the appropriate sizes and length for commercial and home use.
Sciencing Video Vault
The Extraction Process
Since granite needs to be extracted in large pieces, typical methods of large-scale blasting and collection will not work. Instead, large teams of workers with a series of large, specialized equipment and products such as high-capacity extractors, cranes, tamb rock machines, and chemicals. The teams will then slowly dig around the slabs of granite to break them free. Once the slabs have been broken free they are pulled to large trucks capable of carrying heavy loads, or are processed on site depending on the mine. These granite slabs can weight as much as 40 tons.