In geology, it is a crystalline-granular mineral formed during the metamorphism of carbonate rocks (limestone or dolomite) under the influence of high pressures and temperatures. In the construction business, "marble" often means any durable, polished limestone or non-carbonate (for example, silicate) rocks. But true, metamorphogenic marble is precisely limestone that has undergone contact or regional metamorphism, when individual calcite crystals are enlarged at the expense of others. As a result, the rock acquires a granular structure, which is clearly visible on a fresh fracture. Actually, this is one of the characteristic features of "real" marble ..
Natural marble can only be obtained after complete recrystallization of limestone. If the process has not been completed, marbled limestone is obtained. Outwardly, it can be distinguished by the presence in the composition of various fossils (in real marble this is extremely rare and only in areas that have undergone metamorphism to a lesser extent). By its properties (porosity, density, moisture content), marbled limestone is close to ordinary marble.