Marble

Marble is a metamorphic rocks with a crystalline limestone structure formed by the combined action of high pressures and very high temperatures. Marble may be pure (metamorphic origin) or re-composed (sedimentary origin). Marble is not particularly hard (3-4 on the Mohs scale) and is characterized by some degree of variability in the granulometry of components and color shades. The color of marble depends on the presence of mineral impurities (clay, silt, sand, iron oxides and flint/chert nodules); white marble does not contain these impurities.