All ancient and modern cultures have attributed a magical meaning to stones, so much so that some of them are still worshipped as divine. The very word stone is a synonym of eternity and humanity, and has even given rise to people's proper nouns.
Natural stone is fireproof, hygienic, non-toxic and bio-compatible by definition since the earth is made up of it.
The international Neapolitan pizza standard clearly spells it out: "Real Neapolitan pizza is rolled out with skilful hand movements only on a marble surface covered in flour."
Genoese pesto is traditionally made with a wooden pestle in a white marble mortar. Serpentine stone pots are used in Valtellina to cook braised meat because they retain heat, while smoothed soapstone slabs are used as cooking surface.
In ancient oil presses as well as modern ones, olives are poured into the pan mill, where granite wheels called ''macelli" run on the bottom, crushing them and extracting the oil.
A finished product in natural stone is produced through a number of processing stages, consisting in extracting the rock from the original quarry, dividing it into blocks and a second subdivision in elements of specific shape and size. After obtaining the stone element in the desired shape and size, the final processing consists in applying the desired finish to the material. Some surface processes - in addition to resulting in the varying appearance and degrees of colour - also affect the product's performance, such as mechanical resistance, resistance to weathering and soundproofing. The following processes give special features to outdoor use materials:
- Smoothing - Surface processing that dulls and lightens the colour, giving a matte appearance and a smooth and flat surface to the material. It is especially used for outdoor facing in areas where the climate conditions would damage polishing, causing stain effects.
- Polishing - It lends brightness and mirroring properties to the surface, fully highlighting the stone's natural colour. It also gives optimal surface flatness, making the material more hard-wearing.
- Bush Hammering - Process that makes the stone surface very similar to that of the raw material, giving the material a rough surface.
- Sanding - Consists in cutting into the surface by means of a pressurised sand jet. It is also used for cleaning stone materials. The risk consists in making the material more vulnerable to the aggression of weathering.
- Flaming - The most commonly used surface process, together with polishing. It is used to give natural appearance to the stone. However, not all stone withstands the high temperatures required to carry out this process, such as granite, which should be avoided as it contains high percentages of iron, which melts under the action of the flame causing smudges.