Natural stone is practically the only construction material that is placed on site as it comes from nature. During the production processes there is no type of change in its structure, composition or manufacture beyond the cutting and grinding of the surface finish of the pieces.
Among the peculiarities of natural stone, it is necessary to admit certain variations, in terms of color, grain or morphology. Variations that do not constitute defects but singularities of the material, as established by European regulations. When in a project or work the aim is to achieve total homogeneity in the finishes, natural stone is usually not the best alternative for interior or exterior flooring and cladding.
Thanks to nature we have a wide range of natural stones of different properties and colors depending on the geographical area in which we are located. Even within the same exploitation or quarry there may be differences in the same stone due, among other things, to the more or less deep areas of exploitation in which it is extracted at all times.
The regulations are flexible and allow as singularities of the material any visible variation such as cracks, inclusions, cavities, statolites and veins to the extent that they are typical of the stone and do not negatively affect its performance as a construction product. On the other hand, broken pieces, pieces with open fissures on any face, breaks in the corners of the pieces or breaks or chipping of the edges are defects, being a reason for immediate rejection as indicated by the regulations in this regard. Often times these particularities are unknown to developers, builders or individuals who often only have access to a sample of the material. To avoid ending up in a conflict, it is very important that the supplier provides a reference sample, before the start of a work, a sample that must be accepted by all parties (supplier, construction company, construction management, property, etc.) and that In some way, through images, physical samples or criteria, it must be reflected in the contract. On the other hand, the reference sample does not imply a strict uniformity between the sample itself and the actual supply, natural variations can always appear, of which they are unknown until the end of the production process.