Where Does Granite Come From?

The quarrying process.

Granite memorials, headstones, and even signage have a common place in our lives, but do you ever wonder what kind of a process the stone went through before it became the beautiful product you’re looking at today? Where does granite come from? The following video shows the process of quarrying and refining granite into a usable product.

Quarries

Granite can be found in many locations around the world. Different geological areas produce different kinds of granite. For example, most black granite comes from India or China whereas a lot of grey and red come from the United States. The color will determine where it is available. The majority of granite is produced by large quarries in the United States, China, India, Spain, Finland, and Brazil. Rock quarries are a type of mining operation called an open-pit mine. The name comes from the gaping holes that are dug in the earth’s surface as the rock is cut and removed.

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Workers at Keystone finish drilling and prepare for extraction

Extracting Process

Granite is removed from its resting place by two different methods; drilling and jet piercing. The drilling process is most common. Holes are drilled about an inch apart around the sectioned slab. Then a secondary drill removes the remaining stone between the first holes until the chunk breaks free. Jet piercing is a similar method where an extremely hot jet burner flame (about 4,000 degrees Fahrenheit) is directed at the stone. The super heated stone flakes away as it is heated and the burner can be operated like a cutting torch. Once the blocks are free, they are hauled out of the pit by cranes or massive quarry trucks that can hold up to 350 tons.

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14 ft. saw blades cutting granite

Manufacturing & Shipping

Once the stone hits the main manufacturing facility, it is time to begin the beautification process. The slabs are hewn down by enormous circular saws equipped with diamond teeth which allow them cut through the stone like butter. The stone is then moved to an area for polishing. Automated scrubber machines sand down the surface of the cut stone with pads made out of silicone carbine. This process leaves the surface of the stone polished and smooth at which point the true beauty of the piece begins to shine through. After the machines have had their turn, the rock is split into different sizes and hand craftsman put the finishing touches on the shape and polish. The stone is now ready to be shipped from the quarry to the monument dealer. In some cases shape carving and custom designs are completed at the quarry before being shipped to the monument manufacturer.