Polished
Natural stones are polished through the application of abrasive material by polish heads that gradually are changed from coarse to fine. This technique brings out the colour and properties of the polished natural stone.

Natural
A natural finish implies the absence of treatment. It is used exactly as it is extracted, leaving the finish as natural as possible. This finish is mostly used for cladding and cobblestones.

Aged
This treatment involves vibrating the surface of the stone to mimic ageing. Although there are many methods used to go about this treatment, generally all of them lead to a soft surface.

Tumbled
Tumbled is also an ageing treatment to achieve an antique finish. In this case, a vibrating drum-like machine uses finer, more resistant stones, to wear out the surface of the natural stone. This leaves an aged finish and generates a soft surface.

Bush Hammered
This finish is achieved by hitting the surface of the natural stone with a tool called bush hammer. It generates an uneven surface creating craters of different sizes. Through this method, the surface becomes slip-resistant and is used ideally for dense traffic areas.

Sand Blasted
This finish falls in the same category as bush hammered. The surface of the natural stone is blasted with small silica particles using an air gun. This creates little craters on its surface, highlighting the colour of the stone and creating a more slip-resistant finish.

Mushroom
This finish is generally achieved by manual tools which through controlled blows, chip the surface of the natural stone. This creates a rustic appearance, enhancing the texture and irregularities.

Leather
This is achieved by brushing the surface of the natural stone by various brushes. This results in a surface which is soft, warm and smooth to the touch. Very few stones can be treated using this method, including granite.

Flamed
This is done by exposing the surface of the stone to a high-temperature flame. This creates roughness and makes it suitable to withstand exterior use.

Sawn
This is achieved using a diamond disc tooth saw. The surface of the stone is sawn to create a rough and irregular finish. This makes the overall stone lighter and gives it a non-glossy finish. It is generally used for external paving, steps, pathways, driveways and patios.

What is natural stone? It is a stone that is dug up from the earth and is mainly quarried from a mountainous ground. There are many types of natural stones, including slate, granite, limestone, basalt, quartzite, marble, sandstone and travertine etc. The aesthetics and characteristics of natural stone are defined by the process of its formation, e.g. from rivers, from volcanoes, from tectonic folding. Each type of stone is unique as no two places on earth have the same exact geological forces. This also means that the same kind of stone from different areas can differ widely.

The three main processes that natural stone go through in the field of architecture and construction are quarrying, processing and applying.

Quarrying

The process of quarrying is defined as the extraction of these natural stone from the surface of the earth. It is done through different equipment’s and methods, e.g. hand-held tools, explosives and power saws. Hand tools are used when the stone lies in an easily accessible area. The main hand tools are the drill, hammer and wedge. A row of holes is made through the drill and wedges are places within these holes. These wedges are hit with the hammer until it forces the stone to crack along the drilled row of holes. This method is known as the plug and feathers. Explosives and power saws are commonly used for detaching large stone blocks which are then broken down into smaller pieces through the plug and feather method.

Processing

After quarrying the natural stone is in the form of slabs. The slabs can be made of a dimension by sawing. There are many natural stone saws that include diamond-covered blade, gang sawing, straight saw blades and various circular saws. After sawing the next step is to polish the surface of the stone. This is done by using different polish heads, starting from coarse and then slowly moving onto more finer grit abrasives until the surface of the stone is glossy and polished. This way, the stones’ natural texture and the colour are enhanced. Other than this, there are many stone finishes that can be done, including chiselling, sandblasting or heat and flame treatment.

Application

Natural stone is extensively used in the construction industry. Their characteristics have made them one of the most favourite construction materials for humans since many thousands of years. Owing to this, its application has always been diverse. Since many years natural stones were traditionally used in masonry, decoration, indoor flooring, roofing etc. The use of them in veneering for stone wall cladding and facades is an element of modern architecture which has evolved from traditional masonry.

Being a relatively soft rock, tuff has been used for construction and building purposes for thousands of years in human history. Tuff has excellent building properties and is appreciated widely by engineers and architects for its light weight, high quality, strength and low thermal conductivity. Tuff is commonly used to create blocks for the construction of slabs and tiles, while it is also a smart choice for building high-performance roofing and waterproofing protection.

Back in the days of the Soviet Union, the Armenian tuff was employed not only within the USSR territorial construction works but also international engineering and infrastructure projects, an example being the construction of the United Nations headquarters in New York in the year 1951. Armenian tuff belongs to a particularly archaic group of natural rocks that emerged as a result of volcanic activity that took place billions of years ago on our planet. The ancient Romans used tuff for building buildings, bridges and houses that stood as a symbol of eternity, elegance, wealth and power. The porosity and softness of the tuff stone allow it to be treated and handled without using special tools. However, despite its apparent pliability and flexibility, tuff is no less reliable than granite.