A granular limestone or dolomite (a rock composed of calcium-magnesium carbonate) that has been recrystallized under the influence of heat, pressure, and aqueous solutions. This polished stone was used for sculpture and decoration and for architecture from the 7th century BC onwards. Most used were fine white marbles of Greece, though colored marbles were used in Hellenistic architecture. Roman marble, principally from Carrara quarries at Luna, became popular in the 1st century BC.