The surface treatment brings out the esthetic features and determines to a large extent the final look of the stone. Different finishes can mean very different colours and tones. Polishing will usually make the colours look darker and more intense, whereas flaming usually causes the colours to become softer.
The nature of the material and its intended use are important considerations when choosing a finish. use. Indeed, not all finishing options are suitable for all stones. Some granites, for instance, cannot be chiseled and some limestones cannot be polished.
The surface is brilliant, with a mirror effect. Veins, white spots, and fossil structures are clearly visible, colours are enhanced.
The surface is smooth but dull or slightly reflective. There are almost no visible grooves. In wet areas such as bathrooms where there is a risk of slipping, a honed finish may be a better option than a polished one. In areas with a lot of foot traffic, floor tiles are often honed and not polished.
This treatment removes saw marks and achieves a smooth surface with fine, sometimes almost invisible circular marks.
4. Sawed face
The surface is sawn by means of a frame saw, a diamond wire or a diamond disk saw. Saw marks, small waves and lines are visible. Depending on the type of saw used, the marks may be parallel (frame saw, diamond wire saw) or circular (diamond disc saw).
A flame is fired at the stone surface, at an angle of 45°. The thermic shock causes the grains on the surface to burst away. As a result, the surface becomes become rough. Flamed surfaces are used primarily for exterior applications. Flaming is mainly used on the harder types of natural stones.
A mechanical hammer hits the stone and leaves small indentations on the surface. The final result depends on the size of the hammer and the number of points on the hammer. A bush-hammered finish is mainly used in exterior applications.
A high-pressure jet of fine abrasive grains is applied to the surface. It leaves the material with a slightly rough, but fine-grained surface. This finish is mainly used for exterior applications.
Cleaving can be done manually or through mechanical means. The materials split along a natural seam. This finish brings out the original look of the stone: large flakes, holes and bumps in various shapes and at irregular distances are visible.
9. Ice flower
The ‘Ice Flower’ finish involves a mechanical treatment of the stone surface, by means of five chisels (each with four plates) that rotate on their axis and at the same time, move around the stone sheet. The result is a rough surface that resembles the pattern of ice flowers.
A diamond teeth mill grinder is applied perpendicularly to the surface, to achieve the typical flat profile. The grooves always run parallel, the distance between them remains constant. This finish may have unwanted side effects : A slanted pattern in wall-cladding may cause the rainwater to run down along the grooves, causing wear and dirt marks on the façade.
11. Old Chiseled
Grooves are made in the stone surface, either manually or through mechanical means. They usually run at a 45°angle to the edges. This creates a decorative, rough effect.
The tiles are sawn to the required dimensions, and then put into a rotating drum with abrasive particles. As such, the edges of the tiles acquire an aged appearance.
There are different types of ‘brushed’ surfaces on the market. The term means that the original surface (honed, sand-blasted, flamed or sanded) is made smoother by using abrasive brushes under high pressure. After this treatment, the colours of the natural stone become more vivid once again. The surface looks slightly rough, depending on the original finish. Some surface finishes are less commonly used, as they are not suitable for all types of stoned:
Striated: grooves made with a pin, usually on cleft surfaces
Sclype finish: grooves with rough surfaces in between them
Graded: same as sclype finish, but with larger bands
Not all finishes can be achieved for all types of stone. For instance, some marbles cannot be bush-hammered because they are too soft and their multiple and fragile veins might cause them to break. In other cases, the treatment simply makes no sense, because it does nothing to bring out the esthetic features of the stone. For example, marble is hardly ever sanded (as the colors would become dull).
A polished surface is very popular for stones that are used as construction elements : façade cladding, kitchen tops, bathrooms, and floor tiles. One of the reasons for its popularity is that a polished finish is more resistant to atmospheric condition (less pollution, organisms cannot easily stick to the surface). On the other hand, a polished finish may lose its shine in areas with heavy foot traffic. Indeed, a major consideration when choosing the finish is whether the desired esthetic effect can be maintained in the specific environment where the stone will be used. A rough surface will cause more dust and dirt particles to stick to the surface, meaning such a finish requires more maintenance in order to preserve the effect. If there is a real risk of mechanical damage such as scratching, it is preferable not to have an overly smooth surface, as scratching will be more visible on such a surface.