The processing of granite: Step by step

From the moment it is extracted from the quarry up to the time it reaches our homes, granite must undergo a transformation process, overseen at each and every stage by strict quality controls. Today on our blog we invite you to step through this with us. Won´t you join us?

Granite quarrying

Granite is a type of rock formed deep below the earth´s surface from slowly cooling magma.  Large machinery is brought in to extract (or quarry) the granite from open-pit mines using wire saws or diamond wire saws.

Quality control already starts here. After quarrying, much of the stone is sold in blocks, and that which is cut into slabs is then split to make other smaller products such as sidewalks, wall blocks or paving stones. Any blocks with impurities or defects are set aside to undergo further quality tests.

Those blocks that pass the quality controls are sent to the gang saws (cutting machines) where the sawing process begins.

Granite Processing: Sawing

Traditionally, granite blocks were cut by the machines to obtain slabs of the thickness, sizes and finishes required for their final use in the destination works. Now, however, thanks to new technologies, the blocks are cut into slabs by modern wire cutting machinery. These slabs can be cut into varying widths and customised to the client´s requirements. This high-speed new technology delivers superb sawing quality and has greatly increased the production capacity at CKP.

The result is a natural finish with a smooth surface that is a little rough. Although this can be an end finish, other treatments are usually applied depending on the intended use of the granite slab.

Granite Processing: Types of finishes

• Polished

Polished granite is as smooth as glass with a sparkling gloss, and not as porous as other finishes. Its use is recommended almost exclusively for indoors as it has a slippery finish.

• Honed

Honed granite has a buffed or matte appearance and a smooth finish. It is not as shiny as a polished finished but is also recommended for indoor use only.

• Brushed or leathered (textured)

The smooth or rough surface of the granite is gently brushed until it becomes textured and appears worn-in with a very smooth feel. Granite surfaces with this finish are suitable for both indoor and outdoor use, although in the latter case it is recommended to check the slip rate of the surface.

• Grooved

This finish is ideal for outdoor flooring such as curb ramps or pedestrian crossings. The surface has parallel uniform grooves arranged at right-angles to the traffic.

• Natural / Natural cleft

The result is a natural finish that is a little uneven and smoothly and slightly randomly tiered. It is usually used for facades and walls both outdoors and indoors, and especially for rustic paving stones or walls.

• Bush hammered

A specialised stone-working hammer leaves the surface smooth and rugged with small indentations of 1 to 3 millimetres deep, evenly distributed across the whole surface. Like the flamed finish, it is especially suited to outdoor areas.

• Bush Hammered and Brushed

A multi-pointed tool pounds the surface to produce a very rugged surface full of scrapes or lengthened indentations. It is used for rustic decors, as may be the facades of old buildings.

• Sandblasted or Gritted

Uniform in appearance and very similar to the bush hammered finish. The sandblasting process leaves the material with a textured surface. It is because of this rough finish that it is not especially recommended indoors.

• Storage and Shipment

Once the treatment has been applied, the granite slabs are sorted according to the type of finish and are then packed.

Special attention is paid, in this step, to protecting the granite for its subsequent shipment in containers to the end customer.

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