Marble Geology

Marble is a crystalline rock, compact and susceptible to polishing, used for buildings and decorative purposes. It consists of semi-hard minerals belonging to 3 or 4 class on the MOHS scale (calcite, dolomite, serpentine).

The formation - Marble is a metamorphic rock that reaches the consistency and appearance commonly known only at the end of a long process of transformation. The original sedimentary and calcareous rock settles on not too deep marine environments where it is enriched by fossils responsible for the nuances of many marble. The succession of chemical and physical processes transform the fluid sediment in solid rock. The time of lithification is extremely variable: from a very short time to millions of years.

The material, after being subjected to high temperatures and high pressures, undergoes a further transformation: a complete recrystallization of calcium carbonate and the formation of calcite and dolomite. The movements of the earth's crust lead the marble going up until us, close to the surface, where it can be extracted.

The presence of different types of marble is due to the variability of the process that we have just described and may include impurities of various kinds and quantities. It is a common practice, indeed, to distinguish them according to area of origin or the nuances of the colour.

Colour and veins – The colour of marble is extremely variable and is hard to classify. It depends on the lesser or greater presence of mineral impurities such as clay, sand, iron oxides, flint nodules that can be either in granules or in layers within the original sedimentary rock. White marble that are difficult to find, instead, are characterized by the fact that their metamorphization does not allow the presence of impurities. Polychrome marbles are those one that because of their veins have a non-uniform colour.