Marble is a type of metamorphic rock found worldwide where geologic conditions are optimal to transform sedimentary carbonate stone such as limestone or dolomite. The mineral grains are recrystallized under substantial heat and pressure, creating white and colored crystalline rock that can be cut and highly polished.
There are many different types of marble, based on the location and color of the stone. The colors are influenced by the non-carbonate impurities present in the original sedimentary rock, such as clay, sand, iron oxide, silt or chert. The metamorphic transformation veins the marble, which when pure and unpolished, is a waxy white. Sienna marble, for example, is found in the Tuscany region of Italy and is yellow with violet, red, blue or white veins.