By abrasion of the surface of the material, we get the polished finish, an even, smooth and shiny finish that gives a closed porosity to the stone. To get this, the material must have a high degree of crystallinity, something that is very common in many marbles. The polishing gives the stone more resistance to the attack by external agents (weather, impacts, liquid absorption…).
We get this finish by the mechanical abrasion of the surface, using abrasive tools. The surface becomes even and smooth but it is not shiny like in the polished finish. It is the most common finish for limestones and sandstones.
By a mechanic friction process with multiple brushes, we give the stone an aged look, the surface being rough but smooth and non-shiny.
We get the bush-hammered finish by hitting the stone with a bush hammer (a hammer with a grid of spikes on one of the ends). Nowadays, it is made automatically with compressed air and multi head automatic bush-hammer machines. Depending on the size of the spikes, and the strength and quantity of impacts we may get a more or less rough surface. This rustic finish leaves a non-slippery surface, making it ideal for swimming pools, exteriors, parks, stairs…
Using presurized air, we “fire” plenty of sand grains on the stone causing its erosion and giving it a much more slight rustic finish than the one we get by bush-hammering.
Depending on the type of material, the pressure of the air and the type of sand, we will get a more or less pronounced sandblasted.
It consists of applying a flame of more than 2500ºC on the surface of the stone using oxyacetylene lighters. This termal shock causes small and flat fragments and chips of stone to flake off, leaving a rustic touch to the surface. Besides, due to the type of flame and material there is no “burning” on the stone and the resulting surface, hardenend by the fire, is left with an extra protection against adverse weather conditions.
Only the hardest and best quality materials allow flaming, in fact, many others break when applying such a high temperature on them.