In today’s fast-changing home improvement landscape, granite stone is one element that has retained its position and popularity in the industry. The use of granite countertops is nothing new. They are used in both commercial and residential settings for years. There are many reasons that make granite an ideal choice for kitchen countertop. They are its color variety, finishes, hardness, durability, and others. However, it is interesting to know how granite countertops are made. In this post, a detailed explanation of granite will be given touching each & every aspect of granite production.
What is Granite?
Granite is considered an igneous rock that is primarily made up of two minerals – quartz and feldspar. However, other elements can also be present like mica, amphiboles, and a combination of several trace objects. It is important to note that these variations and the abundance of these minerals give granite a particular color and texture. Geologically, granite refers to a plutonic rock that contains nearly 0 to 50% quartz (usually semi-transparent white) and 65 to 90% feldspar, which is usually of white or pink color.
How Granite is formed?
According to geologists, granite was formed when the molten rock cooled down over millions of years.
The larger the mineral crystals formed in molten rock, the slower it cooled, with K-Feldspar megacrysts forming in unusual situations larger than 5cm. Granite is formed beneath kilometers of rock and sediment. This is to produce enough heat to melt the rock.
The granite we see now is at the surface, it was uplifted at some point, forcing overlying sediment to be eroded away. The granite may somewhat expand and crack when it transitions from high pressure and temperature to air pressure and temperature. This, combined with seasonal temperature changes, might result in weakened and less suitable granite for countertops.
Mining of Granite
Granite stone is found in quarries. These quarries are located in different parts of the world. The world’s biggest granite quarry is located in Mount Airy, North Carolina, the U.S which has a size of 66 football fields. Similarly, many other quarries are located in the countries like India, Brazil, Poland, China, Italy, and others. The quality and cost of granite depend on the location of the quarry that is chosen as the source of granite suppliers.
Since there are lots of granite varieties available in the market, not all varieties can be found in these quarries. Some granite variants are specific to a region. Granite is one of the most commonly imported stones across the world.
Granite mining is a massive industrial operation. The raw granite elements are mined in massive, hefty blocks from the earth’s crust. It is the initial step in constructing a granite slab. Granite slabs are obtained from quarries. Miners typically select quarries that are as close to the earth’s surface as possible.
To expose the granite, the layers of dirt above which the stones are produced are first removed. After that, it is extracted from the earth using an open cast mining method. Drilling holes through the granite and then using hydraulic hammers to separate the individual chunks of stone from their surroundings is part of the procedure. Cranes are used to separate the blocks once they have been identified.
After the granite is mined, granite rough blocks of up to 10 tons of weight are moved to granite processing units. In these facilities, these blocks are processed into granite slabs which makes their handling easier.
These slabs are then polished to give a smoother finish to their surface. This process also highlights the natural colors and patterns on them. Different types of polishing machines are used for this. The most widely done finishes are polished, brushed, flamed, Lepatora, bush-hammered, honed, and leathered.
How Granite Slabs are Transformed into Countertops?
Once the slabs are polished, they are cut and shaped given the specific specifications of the countertops. This end-level processing of granite slabs is done keeping in mind the exact application of the granite countertops. For example, if a granite countertop is supposed to be installed in a commercial place, it would be dealt with differently than a granite slab meant for residential use.