Natural Process of Stone

Have you ever asked yourself “where do Global Stone source their natural stone?” Or, “how do they get their stone so smooth or textured?” In this article we explain the process of producing natural stone paving.

What and where is Natural Stone paving made?

Ultimately, natural stone is the material taken from quarried mountains, from the Earth. There are many different types of natural stone: Sandstone, Limestone, Travertine, Marble Granite, and Basalt.

We source our natural stone from all over the globe (hence our name!) including Belgium, Italy, Brazil, China, India, Turkey and right here in the UK. Each region of a country produces different types of stone; for example, we source our Indian Sandstone from Rajasthan and Limestone (specifically Midnight) originates in Tamil Nadu.

The Process of creating Natural Stone Sandstone Paving

Stage 1. Stone is mined from different types of rock:

Igneous (Granite)
Metamorphic (Marble and Slate)
Sedimentary (Sandstone, Yorkstone, Limestone & Travertine)

Sandstone quarry

For this article, we examine the process of creating Sandstone Paving and the various treatments to get the individual finishes.

Stage 2. The stone is sent to the stone cutters in blocks of up to 10 tonnes.

Blocks of stone for selection

Selected block of stone

Stage 3. The paving is hand cut from the large blocks before they are sent for finishing. These are known as flags.

Handcut flags

Stage 4. There are many different types of finishes:
Calibrated:

It is a process which takes flags of variable thickness and runs them through a strip mill. Firstly, a series of closely-spaced saw blades to cut grooves or channels into the underside, nobble-off the remaining upstand, before leaving a flagstone of the selected thickness creating paving stones of an even depth. Secondly, once the flagstones are of a regular thickness, they are laid on a screed laying course. All Global Stone’s sandstone paving products are calibrated.

Calibrated paving Calibrated paving Workers processing calibrated paving

Tumbled:

Natural tumbled tiles have a slightly rounded edge and corners with a soft face. Any type of stone tile can be turned into a tumbled stone tile, including Marble, Granite, Travertine, Limestone, and Slate. All tumbled tiles have a soft, smooth and worn look to them. Therefore, their surface is often slightly chalky or dusty-looking.

The most common tumbling method is to place the tiles into a rubber drum along with rocks, water and sand. The tiles are literally tumbled over and over while the sand, rocks and water wear down their edges and soften their finish. However, not all tiles labelled tumbled are produced this way.

Larger tiles cannot be tumbled this way because they will often break in the process, and those tiles with a honed or polished finish are normally not tumbled in this manner. Instead, these tiles are either hand-chiselled or chipped on the edges, or a machine is used to rough up the edges of the tiles to give them a tumbled look.

Tumbled paving

Our Tumbled products include:

Old Rectory paving, circles, and copings & walling

Victorian paving

Sawn:

There are two types of sawn edges processes: The first image shows the water sawn process where the blocks are cut to the correct thickness. The second image is of edge cutting guided by laser. Our Mirage and Serenity products have ‘sawn’ edges.

Block of paving being sawn Laser cut sawn paving

Sawn products include:

Limestone (Neptune only)

Travertine

Marble

Honed:

Honed means the surface of the stone has been ground to a smooth, flat, consistent surface. Therefore, we achieve a polished finish by using an abrasive to bring out the reflection of the natural crystals, creating a stunning glossy and very smooth surface.

Machine that creates honed paving

Our Honed products include:

Mirage Paving & Setts

Shotblasted:

This method is used to create a lightly roughened texture to the paving. Firstly, the process involves honing the product then peppering the units with shot (small beads of steel), fired at a high velocity with compressed air.

Secondly, the shot spalls the surface a bit at a time, dislodging small particles of stone, the debris falling to the floor, along with the shot. Finally, the debris and shot are removed and separated. The shot is recycled to be used repeatedly in texturing further pieces.

Unlike tumbling, shotblasting produces an even degree of texturing that can be finely controlled by adjusting the time spent in the blast chamber. The textured product is relatively clean, as the shot dislodges any dust as it batters the paver surface.

Shotblasted paving

Shotblasted products include:

Serenity paving

Granite paving

Stage 5. Once the paving is finished, it is packed up and sent either by train and sea straight to our yard. This process can take between 8-12 weeks.

Want to take a closer look at the results? Check out our entire Natural Stone Collection here.